busybox/networking/udhcp/dhcpd.c

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/* vi: set sw=4 ts=4: */
/*
* udhcp server
2006-05-08 08:50:50 +05:30
* Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
* Chris Trew <ctrew@moreton.com.au>
*
* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
2006-05-08 08:50:50 +05:30
*/
//applet:IF_UDHCPD(APPLET(udhcpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_UDHCPD) += common.o packet.o signalpipe.o socket.o
//kbuild:lib-$(CONFIG_UDHCPD) += dhcpd.o arpping.o
//kbuild:lib-$(CONFIG_FEATURE_UDHCP_RFC3397) += domain_codec.o
//usage:#define udhcpd_trivial_usage
//usage: "[-fS] [-I ADDR] [-a MSEC]" IF_FEATURE_UDHCP_PORT(" [-P PORT]") " [CONFFILE]"
//usage:#define udhcpd_full_usage "\n\n"
//usage: "DHCP server\n"
//usage: "\n -f Run in foreground"
//usage: "\n -S Log to syslog too"
//usage: "\n -I ADDR Local address"
//usage: "\n -a MSEC Timeout for ARP ping (default 2000)"
//usage: IF_FEATURE_UDHCP_PORT(
//usage: "\n -P PORT Use PORT (default 67)"
//usage: )
//usage: "\nSignals:"
//usage: "\n USR1 Update lease file"
#include <netinet/ether.h>
#include <syslog.h>
#include "common.h"
#include "dhcpc.h"
2006-05-08 08:50:50 +05:30
#include "dhcpd.h"
#if ENABLE_PID_FILE_PATH
#define PID_FILE_PATH CONFIG_PID_FILE_PATH
#else
#define PID_FILE_PATH "/var/run"
#endif
/* globals */
#define g_leases ((struct dyn_lease*)ptr_to_globals)
/* struct server_data_t server_data is in bb_common_bufsiz1 */
struct static_lease {
struct static_lease *next;
uint32_t nip;
uint8_t mac[6];
uint8_t opt[1];
};
/* Takes the address of the pointer to the static_leases linked list,
* address to a 6 byte mac address,
* 4 byte IP address */
static void add_static_lease(struct static_lease **st_lease_pp,
uint8_t *mac,
uint32_t nip,
const char *opts)
{
struct static_lease *st_lease;
unsigned optlen;
optlen = (opts ? 1+1+strnlen(opts, 120) : 0);
/* Find the tail of the list */
while ((st_lease = *st_lease_pp) != NULL) {
st_lease_pp = &st_lease->next;
}
/* Add new node */
*st_lease_pp = st_lease = xzalloc(sizeof(*st_lease) + optlen);
memcpy(st_lease->mac, mac, 6);
st_lease->nip = nip;
/*st_lease->next = NULL;*/
if (optlen) {
st_lease->opt[OPT_CODE] = DHCP_HOST_NAME;
optlen -= 2;
st_lease->opt[OPT_LEN] = optlen;
memcpy(&st_lease->opt[OPT_DATA], opts, optlen);
}
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
/* Print out static leases just to check what's going on */
if (dhcp_verbose >= 2) {
bb_info_msg("static lease: mac:%02x:%02x:%02x:%02x:%02x:%02x nip:%x",
st_lease->mac[0], st_lease->mac[1], st_lease->mac[2],
st_lease->mac[3], st_lease->mac[4], st_lease->mac[5],
st_lease->nip
);
}
#endif
}
/* Find static lease IP by mac */
static uint32_t get_static_nip_by_mac(void *mac)
{
struct static_lease *st_lease = server_data.static_leases;
while (st_lease) {
if (memcmp(st_lease->mac, mac, 6) == 0)
return st_lease->nip;
st_lease = st_lease->next;
}
return 0;
}
static int is_nip_reserved_as_static(uint32_t nip)
{
struct static_lease *st_lease = server_data.static_leases;
while (st_lease) {
if (st_lease->nip == nip)
return 1;
st_lease = st_lease->next;
}
return 0;
}
/* Find the oldest expired lease, NULL if there are no expired leases */
static struct dyn_lease *oldest_expired_lease(void)
{
struct dyn_lease *oldest_lease = NULL;
leasetime_t oldest_time = time(NULL);
unsigned i;
/* Unexpired leases have g_leases[i].expires >= current time
* and therefore can't ever match */
for (i = 0; i < server_data.max_leases; i++) {
if (g_leases[i].expires == 0 /* empty entry */
|| g_leases[i].expires < oldest_time
) {
oldest_time = g_leases[i].expires;
oldest_lease = &g_leases[i];
}
}
return oldest_lease;
}
/* Clear out all leases with matching nonzero chaddr OR yiaddr.
* If chaddr == NULL, this is a conflict lease.
*/
static void clear_leases(const uint8_t *chaddr, uint32_t yiaddr)
{
unsigned i;
for (i = 0; i < server_data.max_leases; i++) {
if ((chaddr && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
|| (yiaddr && g_leases[i].lease_nip == yiaddr)
) {
memset(&g_leases[i], 0, sizeof(g_leases[i]));
}
}
}
/* Add a lease into the table, clearing out any old ones.
* If chaddr == NULL, this is a conflict lease.
*/
static struct dyn_lease *add_lease(
const uint8_t *chaddr, uint32_t yiaddr,
leasetime_t leasetime,
const char *hostname, int hostname_len)
{
struct dyn_lease *oldest;
/* clean out any old ones */
clear_leases(chaddr, yiaddr);
oldest = oldest_expired_lease();
if (oldest) {
memset(oldest, 0, sizeof(*oldest));
if (hostname) {
char *p;
hostname_len++; /* include NUL */
if (hostname_len > sizeof(oldest->hostname))
hostname_len = sizeof(oldest->hostname);
p = safe_strncpy(oldest->hostname, hostname, hostname_len);
/*
* Sanitization (s/bad_char/./g).
* The intent is not to allow only "DNS-valid" hostnames,
* but merely make dumpleases output safe for shells to use.
* We accept "0-9A-Za-z._-", all other chars turn to dots.
*/
if (*p == '-')
*p = '.'; /* defeat "-option" attacks too */
while (*p) {
if (!isalnum(*p) && *p != '-' && *p != '_')
*p = '.';
p++;
}
}
if (chaddr)
memcpy(oldest->lease_mac, chaddr, 6);
oldest->lease_nip = yiaddr;
oldest->expires = time(NULL) + leasetime;
}
return oldest;
}
/* True if a lease has expired */
static int is_expired_lease(struct dyn_lease *lease)
{
return (lease->expires < (leasetime_t) time(NULL));
}
/* Find the first lease that matches MAC, NULL if no match */
static struct dyn_lease *find_lease_by_mac(const uint8_t *mac)
{
unsigned i;
for (i = 0; i < server_data.max_leases; i++)
if (memcmp(g_leases[i].lease_mac, mac, 6) == 0)
return &g_leases[i];
return NULL;
}
/* Find the first lease that matches IP, NULL is no match */
static struct dyn_lease *find_lease_by_nip(uint32_t nip)
{
unsigned i;
for (i = 0; i < server_data.max_leases; i++)
if (g_leases[i].lease_nip == nip)
return &g_leases[i];
return NULL;
}
/* Check if the IP is taken; if it is, add it to the lease table */
static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac, unsigned arpping_ms)
{
struct in_addr temp;
int r;
r = arpping(nip, safe_mac,
server_data.server_nip,
server_data.server_mac,
server_data.interface,
arpping_ms);
if (r)
return r;
temp.s_addr = nip;
Optionally re-introduce bb_info_msg() Between Busybox 1.24.2 and 1.25.0 the bb_info_msg() function was eliminated and calls to it changed to be bb_error_msg(). The downside of this is that daemons now log all messages to syslog at the LOG_ERR level which makes it hard to filter errors from informational messages. This change optionally re-introduces bb_info_msg(), controlled by a new option FEATURE_SYSLOG_INFO, restores all the calls to bb_info_msg() that were removed (only in applets that set logmode to LOGMODE_SYSLOG or LOGMODE_BOTH), and also changes informational messages in ifplugd and ntpd. The code size change of this is as follows (using 'defconfig' on x86_64 with gcc 7.3.0-27ubuntu1~18.04) function old new delta bb_info_msg - 182 +182 bb_vinfo_msg - 27 +27 static.log7 194 198 +4 log8 190 191 +1 log5 190 191 +1 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 3/0 up/down: 215/-45) Total: 170 bytes If you don't care about everything being logged at LOG_ERR level then when FEATURE_SYSLOG_INFO is disabled Busybox actually gets smaller: function old new delta static.log7 194 200 +6 log8 190 193 +3 log5 190 193 +3 syslog_level 1 - -1 bb_verror_msg 583 581 -2 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 3/1 up/down: 12/-48) Total: -36 bytes Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-12 22:31:51 +05:30
bb_info_msg("%s belongs to someone, reserving it for %u seconds",
inet_ntoa(temp), (unsigned)server_data.conflict_time);
add_lease(NULL, nip, server_data.conflict_time, NULL, 0);
return 0;
}
/* Find a new usable (we think) address */
static uint32_t find_free_or_expired_nip(const uint8_t *safe_mac, unsigned arpping_ms)
{
uint32_t addr;
struct dyn_lease *oldest_lease = NULL;
#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
uint32_t stop;
unsigned i, hash;
/* hash hwaddr: use the SDBM hashing algorithm. Seems to give good
* dispersal even with similarly-valued "strings".
*/
hash = 0;
for (i = 0; i < 6; i++)
hash += safe_mac[i] + (hash << 6) + (hash << 16) - hash;
/* pick a seed based on hwaddr then iterate until we find a free address. */
addr = server_data.start_ip
+ (hash % (1 + server_data.end_ip - server_data.start_ip));
stop = addr;
#else
addr = server_data.start_ip;
#define stop (server_data.end_ip + 1)
#endif
do {
uint32_t nip;
struct dyn_lease *lease;
/* (Addresses ending in .0 or .255 can legitimately be allocated
* in various situations, so _don't_ skip these. The user needs
* to choose start_ip and end_ip correctly for a particular
* network environment.) */
nip = htonl(addr);
/* skip our own address */
if (nip == server_data.server_nip)
goto next_addr;
/* is this a static lease addr? */
if (is_nip_reserved_as_static(nip))
goto next_addr;
lease = find_lease_by_nip(nip);
if (!lease) {
//TODO: DHCP servers do not always sit on the same subnet as clients: should *ping*, not arp-ping!
if (nobody_responds_to_arp(nip, safe_mac, arpping_ms))
return nip;
} else {
if (!oldest_lease || lease->expires < oldest_lease->expires)
oldest_lease = lease;
}
next_addr:
addr++;
#if ENABLE_FEATURE_UDHCPD_BASE_IP_ON_MAC
if (addr > server_data.end_ip)
addr = server_data.start_ip;
#endif
} while (addr != stop);
if (oldest_lease
&& is_expired_lease(oldest_lease)
&& nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac, arpping_ms)
) {
return oldest_lease->lease_nip;
}
return 0;
}
/* On these functions, make sure your datatype matches */
static int FAST_FUNC read_str(const char *line, void *arg)
{
char **dest = arg;
free(*dest);
*dest = xstrdup(line);
return 1;
}
static int FAST_FUNC read_u32(const char *line, void *arg)
{
*(uint32_t*)arg = bb_strtou32(line, NULL, 10);
return errno == 0;
}
static int FAST_FUNC read_staticlease(const char *const_line, void *arg)
{
char *line;
char *mac_string;
char *ip_string;
char *opts;
struct ether_addr mac_bytes; /* it's "struct { uint8_t mac[6]; }" */
uint32_t nip;
/* Read mac */
line = (char *) const_line;
mac_string = strtok_r(line, " \t", &line);
if (!mac_string || !ether_aton_r(mac_string, &mac_bytes))
return 0;
/* Read ip */
ip_string = strtok_r(NULL, " \t", &line);
if (!ip_string || !udhcp_str2nip(ip_string, &nip))
return 0;
opts = strtok_r(NULL, " \t", &line);
/* opts might be NULL, that's not an error */
add_static_lease(arg, (uint8_t*) &mac_bytes, nip, opts);
return 1;
}
static int FAST_FUNC read_optset(const char *line, void *arg)
{
return udhcp_str2optset(line, arg,
dhcp_optflags, dhcp_option_strings,
/*dhcpv6:*/ 0
);
}
struct config_keyword {
const char *keyword;
int (*handler)(const char *line, void *var) FAST_FUNC;
unsigned ofs;
const char *def;
};
#define OFS(field) offsetof(struct server_data_t, field)
static const struct config_keyword keywords[] ALIGN_PTR = {
/* keyword handler variable address default */
{"start" , udhcp_str2nip , OFS(start_ip ), "192.168.0.20"},
{"end" , udhcp_str2nip , OFS(end_ip ), "192.168.0.254"},
{"interface" , read_str , OFS(interface ), "eth0"},
/* Avoid "max_leases value not sane" warning by setting default
* to default_end_ip - default_start_ip + 1: */
{"max_leases" , read_u32 , OFS(max_leases ), "235"},
{"auto_time" , read_u32 , OFS(auto_time ), "7200"},
{"decline_time" , read_u32 , OFS(decline_time ), "3600"},
{"conflict_time", read_u32 , OFS(conflict_time), "3600"},
{"offer_time" , read_u32 , OFS(offer_time ), "60"},
{"min_lease" , read_u32 , OFS(min_lease_sec), "60"},
{"lease_file" , read_str , OFS(lease_file ), LEASES_FILE},
{"pidfile" , read_str , OFS(pidfile ), PID_FILE_PATH "/udhcpd.pid"},
{"siaddr" , udhcp_str2nip , OFS(siaddr_nip ), "0.0.0.0"},
/* keywords with no defaults must be last! */
{"option" , read_optset , OFS(options ), ""},
{"opt" , read_optset , OFS(options ), ""},
{"notify_file" , read_str , OFS(notify_file ), NULL},
{"sname" , read_str , OFS(sname ), NULL},
{"boot_file" , read_str , OFS(boot_file ), NULL},
{"static_lease" , read_staticlease, OFS(static_leases), ""},
};
enum { KWS_WITH_DEFAULTS = ARRAY_SIZE(keywords) - 6 };
static NOINLINE void read_config(const char *file)
{
parser_t *parser;
const struct config_keyword *k;
unsigned i;
char *token[2];
for (i = 0; i < KWS_WITH_DEFAULTS; i++)
keywords[i].handler(keywords[i].def, (char*)&server_data + keywords[i].ofs);
parser = config_open(file);
while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
for (k = keywords, i = 0; i < ARRAY_SIZE(keywords); k++, i++) {
if (strcasecmp(token[0], k->keyword) == 0) {
if (!k->handler(token[1], (char*)&server_data + k->ofs)) {
bb_error_msg("can't parse line %u in %s",
parser->lineno, file);
/* reset back to the default value */
k->handler(k->def, (char*)&server_data + k->ofs);
}
break;
}
}
}
config_close(parser);
server_data.start_ip = ntohl(server_data.start_ip);
server_data.end_ip = ntohl(server_data.end_ip);
if (server_data.start_ip > server_data.end_ip)
bb_error_msg_and_die("bad start/end IP range in %s", file);
}
static void write_leases(void)
{
int fd;
unsigned i;
leasetime_t curr;
int64_t written_at;
fd = open_or_warn(server_data.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
if (fd < 0)
return;
curr = written_at = time(NULL);
written_at = SWAP_BE64(written_at);
full_write(fd, &written_at, sizeof(written_at));
for (i = 0; i < server_data.max_leases; i++) {
leasetime_t tmp_time;
if (g_leases[i].lease_nip == 0)
continue;
/* Screw with the time in the struct, for easier writing */
tmp_time = g_leases[i].expires;
g_leases[i].expires -= curr;
if ((signed_leasetime_t) g_leases[i].expires < 0)
g_leases[i].expires = 0;
g_leases[i].expires = htonl(g_leases[i].expires);
/* No error check. If the file gets truncated,
* we lose some leases on restart. Oh well. */
full_write(fd, &g_leases[i], sizeof(g_leases[i]));
/* Then restore it when done */
g_leases[i].expires = tmp_time;
}
close(fd);
if (server_data.notify_file) {
char *argv[3];
argv[0] = server_data.notify_file;
argv[1] = server_data.lease_file;
argv[2] = NULL;
spawn_and_wait(argv);
}
}
static NOINLINE void read_leases(const char *file)
{
struct dyn_lease lease;
int64_t written_at, time_passed;
int fd;
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
unsigned i = 0;
#endif
fd = open_or_warn(file, O_RDONLY);
if (fd < 0)
return;
if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
goto ret;
written_at = SWAP_BE64(written_at);
time_passed = time(NULL) - written_at;
/* Strange written_at, or lease file from old version of udhcpd
* which had no "written_at" field? */
if ((uint64_t)time_passed > 12 * 60 * 60)
goto ret;
while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
uint32_t y = ntohl(lease.lease_nip);
if (y >= server_data.start_ip && y <= server_data.end_ip) {
signed_leasetime_t expires = ntohl(lease.expires) - (signed_leasetime_t)time_passed;
uint32_t static_nip;
if (expires <= 0)
/* We keep expired leases: add_lease() will add
* a lease with 0 seconds remaining.
* Fewer IP address changes this way for mass reboot scenario.
*/
expires = 0;
/* Check if there is a different static lease for this IP or MAC */
static_nip = get_static_nip_by_mac(lease.lease_mac);
if (static_nip) {
/* NB: we do not add lease even if static_nip == lease.lease_nip.
*/
continue;
}
if (is_nip_reserved_as_static(lease.lease_nip))
continue;
/* NB: add_lease takes "relative time", IOW,
* lease duration, not lease deadline. */
if (add_lease(lease.lease_mac, lease.lease_nip,
expires,
lease.hostname, sizeof(lease.hostname)
) == 0
) {
bb_error_msg("too many leases while loading %s", file);
break;
}
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
i++;
#endif
}
}
log1("read %d leases", i);
ret:
close(fd);
}
2006-05-08 08:50:50 +05:30
/* Send a packet to a specific mac address and ip address by creating our own ip packet */
static void send_packet_to_client(struct dhcp_packet *dhcp_pkt, int force_broadcast)
{
const uint8_t *chaddr;
uint32_t ciaddr;
// Was:
//if (force_broadcast) { /* broadcast */ }
//else if (dhcp_pkt->ciaddr) { /* unicast to dhcp_pkt->ciaddr */ }
//else if (dhcp_pkt->flags & htons(BROADCAST_FLAG)) { /* broadcast */ }
//else { /* unicast to dhcp_pkt->yiaddr */ }
// But this is wrong: yiaddr is _our_ idea what client's IP is
// (for example, from lease file). Client may not know that,
// and may not have UDP socket listening on that IP!
// We should never unicast to dhcp_pkt->yiaddr!
// dhcp_pkt->ciaddr, OTOH, comes from client's request packet,
// and can be used.
if (force_broadcast
|| (dhcp_pkt->flags & htons(BROADCAST_FLAG))
|| dhcp_pkt->ciaddr == 0
) {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
log1s("broadcasting packet to client");
ciaddr = INADDR_BROADCAST;
chaddr = MAC_BCAST_ADDR;
} else {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
log1s("unicasting packet to client ciaddr");
ciaddr = dhcp_pkt->ciaddr;
chaddr = dhcp_pkt->chaddr;
}
udhcp_send_raw_packet(dhcp_pkt,
/*src*/ server_data.server_nip, SERVER_PORT,
/*dst*/ ciaddr, CLIENT_PORT, chaddr,
server_data.ifindex);
}
/* Send a packet to gateway_nip using the kernel ip stack */
static void send_packet_to_relay(struct dhcp_packet *dhcp_pkt)
{
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
log1s("forwarding packet to relay");
udhcp_send_kernel_packet(dhcp_pkt,
server_data.server_nip, SERVER_PORT,
dhcp_pkt->gateway_nip, SERVER_PORT,
server_data.interface);
}
static void send_packet(struct dhcp_packet *dhcp_pkt, int force_broadcast)
{
if (dhcp_pkt->gateway_nip)
send_packet_to_relay(dhcp_pkt);
else
send_packet_to_client(dhcp_pkt, force_broadcast);
}
static void send_packet_verbose(struct dhcp_packet *dhcp_pkt, const char *fmt)
{
struct in_addr addr;
addr.s_addr = dhcp_pkt->yiaddr;
bb_info_msg(fmt, inet_ntoa(addr));
/* send_packet emits error message itself if it detects failure */
send_packet(dhcp_pkt, /*force_bcast:*/ 0);
}
static void init_packet(struct dhcp_packet *packet, struct dhcp_packet *oldpacket, char type)
{
/* Sets op, htype, hlen, cookie fields
* and adds DHCP_MESSAGE_TYPE option */
udhcp_init_header(packet, type);
packet->xid = oldpacket->xid;
memcpy(packet->chaddr, oldpacket->chaddr, sizeof(oldpacket->chaddr));
packet->flags = oldpacket->flags;
packet->gateway_nip = oldpacket->gateway_nip;
packet->ciaddr = oldpacket->ciaddr;
udhcp_add_simple_option(packet, DHCP_SERVER_ID, server_data.server_nip);
}
/* Fill options field, siaddr_nip, and sname and boot_file fields.
* TODO: teach this code to use overload option.
*/
static void add_server_options(struct dhcp_packet *packet)
{
struct option_set *config_opts;
uint8_t *client_hostname_opt;
client_hostname_opt = NULL;
if (packet->yiaddr) { /* if we aren't from send_inform()... */
struct static_lease *st_lease = server_data.static_leases;
while (st_lease) {
if (st_lease->nip == packet->yiaddr) {
if (st_lease->opt[0] != 0)
client_hostname_opt = st_lease->opt;
break;
}
st_lease = st_lease->next;
}
}
config_opts = server_data.options;
while (config_opts) {
if (config_opts->data[OPT_CODE] != DHCP_LEASE_TIME) {
/* ^^^^
* DHCP_LEASE_TIME is already filled, or in case of
* send_inform(), should not be filled at all.
*/
if (config_opts->data[OPT_CODE] != DHCP_HOST_NAME
|| !client_hostname_opt
) {
/* Why "!client_hostname_opt":
* add hostname only if client has no hostname
* on its static lease line.
* (Not that "opt hostname HOST"
* makes much sense in udhcpd.conf,
* that'd give all clients the same hostname,
* but it's a valid configuration).
*/
udhcp_add_binary_option(packet, config_opts->data);
}
}
config_opts = config_opts->next;
}
if (client_hostname_opt)
udhcp_add_binary_option(packet, client_hostname_opt);
packet->siaddr_nip = server_data.siaddr_nip;
if (server_data.sname)
strncpy((char*)packet->sname, server_data.sname, sizeof(packet->sname) - 1);
if (server_data.boot_file)
strncpy((char*)packet->file, server_data.boot_file, sizeof(packet->file) - 1);
}
static uint32_t select_lease_time(struct dhcp_packet *packet)
{
uint32_t lease_time_sec = server_data.max_lease_sec;
uint8_t *lease_time_opt = udhcp_get_option32(packet, DHCP_LEASE_TIME);
if (lease_time_opt) {
move_from_unaligned32(lease_time_sec, lease_time_opt);
lease_time_sec = ntohl(lease_time_sec);
if (lease_time_sec > server_data.max_lease_sec)
lease_time_sec = server_data.max_lease_sec;
if (lease_time_sec < server_data.min_lease_sec)
lease_time_sec = server_data.min_lease_sec;
}
return lease_time_sec;
}
/* We got a DHCP DISCOVER. Send an OFFER. */
/* NOINLINE: limit stack usage in caller */
static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
uint32_t static_lease_nip,
struct dyn_lease *lease,
uint32_t requested_nip,
unsigned arpping_ms)
{
struct dhcp_packet packet;
uint32_t lease_time_sec;
init_packet(&packet, oldpacket, DHCPOFFER);
/* If it is a static lease, use its IP */
packet.yiaddr = static_lease_nip;
/* Else: */
if (!static_lease_nip) {
/* We have no static lease for client's chaddr */
const char *p_host_name;
if (lease) {
/* We have a dynamic lease for client's chaddr.
* Reuse its IP (even if lease is expired).
* Note that we ignore requested IP in this case.
*/
packet.yiaddr = lease->lease_nip;
}
/* Or: if client has requested an IP */
else if (requested_nip != 0
/* and the IP is in the lease range */
&& ntohl(requested_nip) >= server_data.start_ip
&& ntohl(requested_nip) <= server_data.end_ip
/* and */
&& ( !(lease = find_lease_by_nip(requested_nip)) /* is not already taken */
|| is_expired_lease(lease) /* or is taken, but expired */
)
) {
packet.yiaddr = requested_nip;
}
else {
/* Otherwise, find a free IP */
packet.yiaddr = find_free_or_expired_nip(oldpacket->chaddr, arpping_ms);
}
if (!packet.yiaddr) {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_simple_error_msg("no free IP addresses. OFFER abandoned");
return;
}
/* Reserve the IP for a short time hoping to get DHCPREQUEST soon */
p_host_name = (const char*) udhcp_get_option(oldpacket, DHCP_HOST_NAME);
lease = add_lease(packet.chaddr, packet.yiaddr,
server_data.offer_time,
p_host_name,
p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
);
if (!lease) {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_simple_error_msg("no free IP addresses. OFFER abandoned");
return;
}
}
lease_time_sec = select_lease_time(oldpacket);
udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
add_server_options(&packet);
/* send_packet emits error message itself if it detects failure */
send_packet_verbose(&packet, "sending OFFER to %s");
}
/* NOINLINE: limit stack usage in caller */
static NOINLINE void send_NAK(struct dhcp_packet *oldpacket)
{
struct dhcp_packet packet;
init_packet(&packet, oldpacket, DHCPNAK);
log1("sending %s", "NAK");
send_packet(&packet, /*force_bcast:*/ 1);
}
/* NOINLINE: limit stack usage in caller */
static NOINLINE void send_ACK(struct dhcp_packet *oldpacket, uint32_t yiaddr)
{
struct dhcp_packet packet;
uint32_t lease_time_sec;
const char *p_host_name;
init_packet(&packet, oldpacket, DHCPACK);
packet.yiaddr = yiaddr;
lease_time_sec = select_lease_time(oldpacket);
udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
add_server_options(&packet);
send_packet_verbose(&packet, "sending ACK to %s");
p_host_name = (const char*) udhcp_get_option(oldpacket, DHCP_HOST_NAME);
add_lease(packet.chaddr, packet.yiaddr,
lease_time_sec,
p_host_name,
p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
);
if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
/* rewrite the file with leases at every new acceptance */
write_leases();
}
}
/* NOINLINE: limit stack usage in caller */
static NOINLINE void send_inform(struct dhcp_packet *oldpacket)
{
struct dhcp_packet packet;
/* "If a client has obtained a network address through some other means
* (e.g., manual configuration), it may use a DHCPINFORM request message
* to obtain other local configuration parameters. Servers receiving a
* DHCPINFORM message construct a DHCPACK message with any local
* configuration parameters appropriate for the client without:
* allocating a new address, checking for an existing binding, filling
* in 'yiaddr' or including lease time parameters. The servers SHOULD
* unicast the DHCPACK reply to the address given in the 'ciaddr' field
* of the DHCPINFORM message.
* ...
* The server responds to a DHCPINFORM message by sending a DHCPACK
* message directly to the address given in the 'ciaddr' field
* of the DHCPINFORM message. The server MUST NOT send a lease
* expiration time to the client and SHOULD NOT fill in 'yiaddr'."
*/
//TODO: do a few sanity checks: is ciaddr set?
//Better yet: is ciaddr == IP source addr?
init_packet(&packet, oldpacket, DHCPACK);
add_server_options(&packet);
send_packet(&packet, /*force_bcast:*/ 0);
// or maybe? send_packet_verbose(&packet, "sending ACK to %s");
}
int udhcpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2008-07-05 14:48:54 +05:30
int udhcpd_main(int argc UNUSED_PARAM, char **argv)
2006-05-08 08:50:50 +05:30
{
int server_socket = -1, retval;
unsigned timeout_end;
unsigned num_ips;
unsigned opt;
2006-05-08 08:50:50 +05:30
struct option_set *option;
char *str_I = str_I;
const char *str_a = "2000";
unsigned arpping_ms;
IF_FEATURE_UDHCP_PORT(char *str_P;)
2006-05-08 08:50:50 +05:30
setup_common_bufsiz();
IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
/* Make sure fd 0,1,2 are open */
/* Setup the signal pipe on fds 3,4 - must be before openlog() */
udhcp_sp_setup();
#define OPT_f (1 << 0)
#define OPT_S (1 << 1)
#define OPT_I (1 << 2)
#define OPT_v (1 << 3)
#define OPT_a (1 << 4)
#define OPT_P (1 << 5)
getopt32: remove opt_complementary function old new delta vgetopt32 1318 1392 +74 runsvdir_main 703 713 +10 bb_make_directory 423 425 +2 collect_cpu 546 545 -1 opt_chars 3 - -3 opt_complementary 4 - -4 tftpd_main 567 562 -5 ntp_init 476 471 -5 zcip_main 1266 1256 -10 xxd_main 428 418 -10 whois_main 140 130 -10 who_main 463 453 -10 which_main 212 202 -10 wget_main 2535 2525 -10 watchdog_main 291 281 -10 watch_main 222 212 -10 vlock_main 399 389 -10 uuencode_main 332 322 -10 uudecode_main 316 306 -10 unlink_main 45 35 -10 udhcpd_main 1482 1472 -10 udhcpc_main 2762 2752 -10 tune2fs_main 290 280 -10 tunctl_main 366 356 -10 truncate_main 218 208 -10 tr_main 518 508 -10 time_main 1134 1124 -10 tftp_main 286 276 -10 telnetd_main 1873 1863 -10 tcpudpsvd_main 1785 1775 -10 taskset_main 521 511 -10 tar_main 1009 999 -10 tail_main 1644 1634 -10 syslogd_main 1967 1957 -10 switch_root_main 368 358 -10 svlogd_main 1454 1444 -10 sv 1296 1286 -10 stat_main 104 94 -10 start_stop_daemon_main 1028 1018 -10 split_main 542 532 -10 sort_main 796 786 -10 slattach_main 624 614 -10 shuf_main 504 494 -10 setsid_main 96 86 -10 setserial_main 1132 1122 -10 setfont_main 388 378 -10 setconsole_main 78 68 -10 sendmail_main 1209 1199 -10 sed_main 677 667 -10 script_main 1077 1067 -10 run_parts_main 325 315 -10 rtcwake_main 454 444 -10 rm_main 175 165 -10 reformime_main 119 109 -10 readlink_main 123 113 -10 rdate_main 246 236 -10 pwdx_main 189 179 -10 pstree_main 317 307 -10 pscan_main 663 653 -10 popmaildir_main 818 808 -10 pmap_main 80 70 -10 nc_main 1042 1032 -10 mv_main 558 548 -10 mountpoint_main 477 467 -10 mount_main 1264 1254 -10 modprobe_main 768 758 -10 modinfo_main 333 323 -10 mktemp_main 200 190 -10 mkswap_main 324 314 -10 mkfs_vfat_main 1489 1479 -10 microcom_main 715 705 -10 md5_sha1_sum_main 521 511 -10 man_main 867 857 -10 makedevs_main 1052 1042 -10 ls_main 563 553 -10 losetup_main 432 422 -10 loadfont_main 89 79 -10 ln_main 524 514 -10 link_main 75 65 -10 ipcalc_main 544 534 -10 iostat_main 2397 2387 -10 install_main 768 758 -10 id_main 480 470 -10 i2cset_main 1239 1229 -10 i2cget_main 380 370 -10 i2cdump_main 1482 1472 -10 i2cdetect_main 682 672 -10 hwclock_main 406 396 -10 httpd_main 741 731 -10 grep_main 837 827 -10 getty_main 1559 1549 -10 fuser_main 297 287 -10 ftpgetput_main 345 335 -10 ftpd_main 2232 2222 -10 fstrim_main 251 241 -10 fsfreeze_main 77 67 -10 fsck_minix_main 2921 2911 -10 flock_main 314 304 -10 flashcp_main 740 730 -10 flash_eraseall_main 833 823 -10 fdformat_main 532 522 -10 expand_main 680 670 -10 eject_main 335 325 -10 dumpleases_main 630 620 -10 du_main 314 304 -10 dos2unix_main 441 431 -10 diff_main 1350 1340 -10 df_main 1064 1054 -10 date_main 1095 1085 -10 cut_main 961 951 -10 cryptpw_main 228 218 -10 crontab_main 575 565 -10 crond_main 1149 1139 -10 cp_main 370 360 -10 common_traceroute_main 3834 3824 -10 common_ping_main 1767 1757 -10 comm_main 239 229 -10 cmp_main 655 645 -10 chrt_main 379 369 -10 chpst_main 704 694 -10 chpasswd_main 308 298 -10 chown_main 171 161 -10 chmod_main 158 148 -10 cat_main 428 418 -10 bzip2_main 120 110 -10 blkdiscard_main 264 254 -10 base64_main 221 211 -10 arping_main 1665 1655 -10 ar_main 556 546 -10 adjtimex_main 406 396 -10 adduser_main 882 872 -10 addgroup_main 411 401 -10 acpid_main 1198 1188 -10 optstring 11 - -11 opt_string 18 - -18 OPT_STR 25 - -25 ubi_tools_main 1288 1258 -30 ls_options 31 - -31 ------------------------------------------------------------------------------ (add/remove: 0/6 grow/shrink: 3/129 up/down: 86/-1383) Total: -1297 bytes text data bss dec hex filename 915428 485 6876 922789 e14a5 busybox_old 914629 485 6872 921986 e1182 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-09 01:25:02 +05:30
opt = getopt32(argv, "^"
"fSI:va:"IF_FEATURE_UDHCP_PORT("P:")
"\0"
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
getopt32: remove opt_complementary function old new delta vgetopt32 1318 1392 +74 runsvdir_main 703 713 +10 bb_make_directory 423 425 +2 collect_cpu 546 545 -1 opt_chars 3 - -3 opt_complementary 4 - -4 tftpd_main 567 562 -5 ntp_init 476 471 -5 zcip_main 1266 1256 -10 xxd_main 428 418 -10 whois_main 140 130 -10 who_main 463 453 -10 which_main 212 202 -10 wget_main 2535 2525 -10 watchdog_main 291 281 -10 watch_main 222 212 -10 vlock_main 399 389 -10 uuencode_main 332 322 -10 uudecode_main 316 306 -10 unlink_main 45 35 -10 udhcpd_main 1482 1472 -10 udhcpc_main 2762 2752 -10 tune2fs_main 290 280 -10 tunctl_main 366 356 -10 truncate_main 218 208 -10 tr_main 518 508 -10 time_main 1134 1124 -10 tftp_main 286 276 -10 telnetd_main 1873 1863 -10 tcpudpsvd_main 1785 1775 -10 taskset_main 521 511 -10 tar_main 1009 999 -10 tail_main 1644 1634 -10 syslogd_main 1967 1957 -10 switch_root_main 368 358 -10 svlogd_main 1454 1444 -10 sv 1296 1286 -10 stat_main 104 94 -10 start_stop_daemon_main 1028 1018 -10 split_main 542 532 -10 sort_main 796 786 -10 slattach_main 624 614 -10 shuf_main 504 494 -10 setsid_main 96 86 -10 setserial_main 1132 1122 -10 setfont_main 388 378 -10 setconsole_main 78 68 -10 sendmail_main 1209 1199 -10 sed_main 677 667 -10 script_main 1077 1067 -10 run_parts_main 325 315 -10 rtcwake_main 454 444 -10 rm_main 175 165 -10 reformime_main 119 109 -10 readlink_main 123 113 -10 rdate_main 246 236 -10 pwdx_main 189 179 -10 pstree_main 317 307 -10 pscan_main 663 653 -10 popmaildir_main 818 808 -10 pmap_main 80 70 -10 nc_main 1042 1032 -10 mv_main 558 548 -10 mountpoint_main 477 467 -10 mount_main 1264 1254 -10 modprobe_main 768 758 -10 modinfo_main 333 323 -10 mktemp_main 200 190 -10 mkswap_main 324 314 -10 mkfs_vfat_main 1489 1479 -10 microcom_main 715 705 -10 md5_sha1_sum_main 521 511 -10 man_main 867 857 -10 makedevs_main 1052 1042 -10 ls_main 563 553 -10 losetup_main 432 422 -10 loadfont_main 89 79 -10 ln_main 524 514 -10 link_main 75 65 -10 ipcalc_main 544 534 -10 iostat_main 2397 2387 -10 install_main 768 758 -10 id_main 480 470 -10 i2cset_main 1239 1229 -10 i2cget_main 380 370 -10 i2cdump_main 1482 1472 -10 i2cdetect_main 682 672 -10 hwclock_main 406 396 -10 httpd_main 741 731 -10 grep_main 837 827 -10 getty_main 1559 1549 -10 fuser_main 297 287 -10 ftpgetput_main 345 335 -10 ftpd_main 2232 2222 -10 fstrim_main 251 241 -10 fsfreeze_main 77 67 -10 fsck_minix_main 2921 2911 -10 flock_main 314 304 -10 flashcp_main 740 730 -10 flash_eraseall_main 833 823 -10 fdformat_main 532 522 -10 expand_main 680 670 -10 eject_main 335 325 -10 dumpleases_main 630 620 -10 du_main 314 304 -10 dos2unix_main 441 431 -10 diff_main 1350 1340 -10 df_main 1064 1054 -10 date_main 1095 1085 -10 cut_main 961 951 -10 cryptpw_main 228 218 -10 crontab_main 575 565 -10 crond_main 1149 1139 -10 cp_main 370 360 -10 common_traceroute_main 3834 3824 -10 common_ping_main 1767 1757 -10 comm_main 239 229 -10 cmp_main 655 645 -10 chrt_main 379 369 -10 chpst_main 704 694 -10 chpasswd_main 308 298 -10 chown_main 171 161 -10 chmod_main 158 148 -10 cat_main 428 418 -10 bzip2_main 120 110 -10 blkdiscard_main 264 254 -10 base64_main 221 211 -10 arping_main 1665 1655 -10 ar_main 556 546 -10 adjtimex_main 406 396 -10 adduser_main 882 872 -10 addgroup_main 411 401 -10 acpid_main 1198 1188 -10 optstring 11 - -11 opt_string 18 - -18 OPT_STR 25 - -25 ubi_tools_main 1288 1258 -30 ls_options 31 - -31 ------------------------------------------------------------------------------ (add/remove: 0/6 grow/shrink: 3/129 up/down: 86/-1383) Total: -1297 bytes text data bss dec hex filename 915428 485 6876 922789 e14a5 busybox_old 914629 485 6872 921986 e1182 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-09 01:25:02 +05:30
"vv"
#endif
, &str_I
, &str_a
IF_FEATURE_UDHCP_PORT(, &str_P)
IF_UDHCP_VERBOSE(, &dhcp_verbose)
);
if (!(opt & OPT_f)) { /* no -f */
bb_daemonize_or_rexec(0, argv);
logmode = LOGMODE_NONE;
}
/* update argv after the possible vfork+exec in daemonize */
argv += optind;
if (opt & OPT_S) {
openlog(applet_name, LOG_PID, LOG_DAEMON);
logmode |= LOGMODE_SYSLOG;
}
if (opt & OPT_I) {
len_and_sockaddr *lsa = xhost_and_af2sockaddr(str_I, 0, AF_INET);
server_data.server_nip = lsa->u.sin.sin_addr.s_addr;
free(lsa);
}
#if ENABLE_FEATURE_UDHCP_PORT
if (opt & OPT_P) {
SERVER_PORT = xatou16(str_P);
CLIENT_PORT = SERVER_PORT + 1;
}
#endif
arpping_ms = xatou(str_a);
/* Would rather not do read_config before daemonization -
* otherwise NOMMU machines will parse config twice */
2007-08-16 01:33:36 +05:30
read_config(argv[0] ? argv[0] : DHCPD_CONF_FILE);
/* prevent poll timeout overflow */
if (server_data.auto_time > INT_MAX / 1000)
server_data.auto_time = INT_MAX / 1000;
2006-05-08 08:50:50 +05:30
/* Create pidfile */
write_pidfile(server_data.pidfile);
/* if (!..) bb_perror_msg("can't create pidfile %s", pidfile); */
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_simple_info_msg("started, v"BB_VER);
2006-05-08 08:50:50 +05:30
option = udhcp_find_option(server_data.options, DHCP_LEASE_TIME);
server_data.max_lease_sec = DEFAULT_LEASE_TIME;
if (option) {
move_from_unaligned32(server_data.max_lease_sec, option->data + OPT_DATA);
server_data.max_lease_sec = ntohl(server_data.max_lease_sec);
}
2006-05-08 08:50:50 +05:30
/* Sanity check */
num_ips = server_data.end_ip - server_data.start_ip + 1;
if (server_data.max_leases > num_ips) {
bb_error_msg("max_leases=%u is too big, setting to %u",
(unsigned)server_data.max_leases, num_ips);
server_data.max_leases = num_ips;
2006-05-08 08:50:50 +05:30
}
/* this sets g_leases */
SET_PTR_TO_GLOBALS(xzalloc(server_data.max_leases * sizeof(g_leases[0])));
read_leases(server_data.lease_file);
2006-05-08 08:50:50 +05:30
if (udhcp_read_interface(server_data.interface,
&server_data.ifindex,
(server_data.server_nip == 0 ? &server_data.server_nip : NULL),
server_data.server_mac)
) {
retval = 1;
goto ret;
}
2006-05-08 08:50:50 +05:30
continue_with_autotime:
timeout_end = monotonic_sec() + server_data.auto_time;
while (1) { /* loop until universe collapses */
struct pollfd pfds[2];
struct dhcp_packet packet;
int bytes;
int tv;
uint8_t *msg_type;
uint8_t *server_id_opt;
uint8_t *requested_ip_opt;
uint32_t requested_nip;
uint32_t static_lease_nip;
struct dyn_lease *lease, fake_lease;
2006-05-08 08:50:50 +05:30
2006-11-28 05:13:28 +05:30
if (server_socket < 0) {
server_socket = udhcp_listen_socket(/*INADDR_ANY,*/ SERVER_PORT,
server_data.interface);
2006-11-28 05:13:28 +05:30
}
2006-05-08 08:50:50 +05:30
udhcp_sp_fd_set(pfds, server_socket);
new_tv:
tv = -1;
if (server_data.auto_time) {
tv = timeout_end - monotonic_sec();
if (tv <= 0) {
write_leases:
udhcpd: fix "not dying on SIGTERM" Fixes: commit 52a515d18724bbb34e3ccbbb0218efcc4eccc0a8 "udhcp: use poll() instead of select()" Feb 16 2017 udhcp_sp_read() is meant to check whether signal pipe indeed has some data to read. In the above commit, it was changed as follows: - if (!FD_ISSET(signal_pipe.rd, rfds)) + if (!pfds[0].revents) return 0; The problem is, the check was working for select() purely by accident. Caught signal interrupts select()/poll() syscalls, they return with EINTR (regardless of SA_RESTART flag in sigaction). _Then_ signal handler is invoked. IOW: they can't see any changes to fd state caused by signal haldler (in our case, signal handler makes signal pipe ready to be read). For select(), it means that rfds[] bit array is unmodified, bit of signal pipe's read fd is still set, and the above check "works": it thinks select() says there is data to read. This accident does not work for poll(): .revents stays clear, and we do not try reading signal pipe as we should. In udhcpd, we fall through and block in socket read. Further SIGTERM signals simply cause socket read to be interrupted and then restarted (since SIGTERM handler has SA_RESTART=1). Fixing this as follows: remove the check altogether. Set signal pipe read fd to nonblocking mode. Always read it in udhcp_sp_read(). If read fails, assume it's EAGAIN and return 0 ("no signal seen"). udhcpd avoids reading signal pipe on every recvd packet by looping if EINTR (using safe_poll()) - thus ensuring we have correct .revents for all fds - and calling udhcp_sp_read() only if pfds[0].revents!=0. udhcpc performs much fewer reads (typically it sleeps >99.999% of the time), there is no need to optimize it: can call udhcp_sp_read() after each poll unconditionally. To robustify socket reads, unconditionally set pfds[1].revents=0 in udhcp_sp_fd_set() (which is before poll), and check it before reading network socket in udhcpd. TODO: This might still fail: if pfds[1].revents=POLLIN, socket read may still block. There are rare cases when select/poll indicates that data can be read, but then actual read still blocks (one such case is UDP packets with wrong checksum). General advise is, if you use a poll/select loop, keep all your fds nonblocking. Maybe we should also do that to our network sockets? function old new delta udhcp_sp_setup 55 65 +10 udhcp_sp_fd_set 54 60 +6 udhcp_sp_read 46 36 -10 udhcpd_main 1451 1437 -14 udhcpc_main 2723 2708 -15 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/3 up/down: 16/-39) Total: -23 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-03-10 23:31:48 +05:30
write_leases();
goto continue_with_autotime;
}
tv *= 1000;
}
/* Block here waiting for either signal or packet */
retval = poll(pfds, 2, tv);
if (retval <= 0) {
if (retval == 0)
goto write_leases;
if (errno == EINTR)
goto new_tv;
udhcpd: fix "not dying on SIGTERM" Fixes: commit 52a515d18724bbb34e3ccbbb0218efcc4eccc0a8 "udhcp: use poll() instead of select()" Feb 16 2017 udhcp_sp_read() is meant to check whether signal pipe indeed has some data to read. In the above commit, it was changed as follows: - if (!FD_ISSET(signal_pipe.rd, rfds)) + if (!pfds[0].revents) return 0; The problem is, the check was working for select() purely by accident. Caught signal interrupts select()/poll() syscalls, they return with EINTR (regardless of SA_RESTART flag in sigaction). _Then_ signal handler is invoked. IOW: they can't see any changes to fd state caused by signal haldler (in our case, signal handler makes signal pipe ready to be read). For select(), it means that rfds[] bit array is unmodified, bit of signal pipe's read fd is still set, and the above check "works": it thinks select() says there is data to read. This accident does not work for poll(): .revents stays clear, and we do not try reading signal pipe as we should. In udhcpd, we fall through and block in socket read. Further SIGTERM signals simply cause socket read to be interrupted and then restarted (since SIGTERM handler has SA_RESTART=1). Fixing this as follows: remove the check altogether. Set signal pipe read fd to nonblocking mode. Always read it in udhcp_sp_read(). If read fails, assume it's EAGAIN and return 0 ("no signal seen"). udhcpd avoids reading signal pipe on every recvd packet by looping if EINTR (using safe_poll()) - thus ensuring we have correct .revents for all fds - and calling udhcp_sp_read() only if pfds[0].revents!=0. udhcpc performs much fewer reads (typically it sleeps >99.999% of the time), there is no need to optimize it: can call udhcp_sp_read() after each poll unconditionally. To robustify socket reads, unconditionally set pfds[1].revents=0 in udhcp_sp_fd_set() (which is before poll), and check it before reading network socket in udhcpd. TODO: This might still fail: if pfds[1].revents=POLLIN, socket read may still block. There are rare cases when select/poll indicates that data can be read, but then actual read still blocks (one such case is UDP packets with wrong checksum). General advise is, if you use a poll/select loop, keep all your fds nonblocking. Maybe we should also do that to our network sockets? function old new delta udhcp_sp_setup 55 65 +10 udhcp_sp_fd_set 54 60 +6 udhcp_sp_read 46 36 -10 udhcpd_main 1451 1437 -14 udhcpc_main 2723 2708 -15 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/3 up/down: 16/-39) Total: -23 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-03-10 23:31:48 +05:30
/* < 0 and not EINTR: should not happen */
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_simple_perror_msg_and_die("poll");
2006-05-08 08:50:50 +05:30
}
udhcpd: fix "not dying on SIGTERM" Fixes: commit 52a515d18724bbb34e3ccbbb0218efcc4eccc0a8 "udhcp: use poll() instead of select()" Feb 16 2017 udhcp_sp_read() is meant to check whether signal pipe indeed has some data to read. In the above commit, it was changed as follows: - if (!FD_ISSET(signal_pipe.rd, rfds)) + if (!pfds[0].revents) return 0; The problem is, the check was working for select() purely by accident. Caught signal interrupts select()/poll() syscalls, they return with EINTR (regardless of SA_RESTART flag in sigaction). _Then_ signal handler is invoked. IOW: they can't see any changes to fd state caused by signal haldler (in our case, signal handler makes signal pipe ready to be read). For select(), it means that rfds[] bit array is unmodified, bit of signal pipe's read fd is still set, and the above check "works": it thinks select() says there is data to read. This accident does not work for poll(): .revents stays clear, and we do not try reading signal pipe as we should. In udhcpd, we fall through and block in socket read. Further SIGTERM signals simply cause socket read to be interrupted and then restarted (since SIGTERM handler has SA_RESTART=1). Fixing this as follows: remove the check altogether. Set signal pipe read fd to nonblocking mode. Always read it in udhcp_sp_read(). If read fails, assume it's EAGAIN and return 0 ("no signal seen"). udhcpd avoids reading signal pipe on every recvd packet by looping if EINTR (using safe_poll()) - thus ensuring we have correct .revents for all fds - and calling udhcp_sp_read() only if pfds[0].revents!=0. udhcpc performs much fewer reads (typically it sleeps >99.999% of the time), there is no need to optimize it: can call udhcp_sp_read() after each poll unconditionally. To robustify socket reads, unconditionally set pfds[1].revents=0 in udhcp_sp_fd_set() (which is before poll), and check it before reading network socket in udhcpd. TODO: This might still fail: if pfds[1].revents=POLLIN, socket read may still block. There are rare cases when select/poll indicates that data can be read, but then actual read still blocks (one such case is UDP packets with wrong checksum). General advise is, if you use a poll/select loop, keep all your fds nonblocking. Maybe we should also do that to our network sockets? function old new delta udhcp_sp_setup 55 65 +10 udhcp_sp_fd_set 54 60 +6 udhcp_sp_read 46 36 -10 udhcpd_main 1451 1437 -14 udhcpc_main 2723 2708 -15 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/3 up/down: 16/-39) Total: -23 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-03-10 23:31:48 +05:30
if (pfds[0].revents) switch (udhcp_sp_read()) {
2006-05-08 08:50:50 +05:30
case SIGUSR1:
Optionally re-introduce bb_info_msg() Between Busybox 1.24.2 and 1.25.0 the bb_info_msg() function was eliminated and calls to it changed to be bb_error_msg(). The downside of this is that daemons now log all messages to syslog at the LOG_ERR level which makes it hard to filter errors from informational messages. This change optionally re-introduces bb_info_msg(), controlled by a new option FEATURE_SYSLOG_INFO, restores all the calls to bb_info_msg() that were removed (only in applets that set logmode to LOGMODE_SYSLOG or LOGMODE_BOTH), and also changes informational messages in ifplugd and ntpd. The code size change of this is as follows (using 'defconfig' on x86_64 with gcc 7.3.0-27ubuntu1~18.04) function old new delta bb_info_msg - 182 +182 bb_vinfo_msg - 27 +27 static.log7 194 198 +4 log8 190 191 +1 log5 190 191 +1 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 3/0 up/down: 215/-45) Total: 170 bytes If you don't care about everything being logged at LOG_ERR level then when FEATURE_SYSLOG_INFO is disabled Busybox actually gets smaller: function old new delta static.log7 194 200 +6 log8 190 193 +3 log5 190 193 +3 syslog_level 1 - -1 bb_verror_msg 583 581 -2 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 3/1 up/down: 12/-48) Total: -36 bytes Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-12 22:31:51 +05:30
bb_info_msg("received %s", "SIGUSR1");
2006-05-08 08:50:50 +05:30
write_leases();
/* why not just reset the timeout, eh */
goto continue_with_autotime;
2006-05-08 08:50:50 +05:30
case SIGTERM:
Optionally re-introduce bb_info_msg() Between Busybox 1.24.2 and 1.25.0 the bb_info_msg() function was eliminated and calls to it changed to be bb_error_msg(). The downside of this is that daemons now log all messages to syslog at the LOG_ERR level which makes it hard to filter errors from informational messages. This change optionally re-introduces bb_info_msg(), controlled by a new option FEATURE_SYSLOG_INFO, restores all the calls to bb_info_msg() that were removed (only in applets that set logmode to LOGMODE_SYSLOG or LOGMODE_BOTH), and also changes informational messages in ifplugd and ntpd. The code size change of this is as follows (using 'defconfig' on x86_64 with gcc 7.3.0-27ubuntu1~18.04) function old new delta bb_info_msg - 182 +182 bb_vinfo_msg - 27 +27 static.log7 194 198 +4 log8 190 191 +1 log5 190 191 +1 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 3/0 up/down: 215/-45) Total: 170 bytes If you don't care about everything being logged at LOG_ERR level then when FEATURE_SYSLOG_INFO is disabled Busybox actually gets smaller: function old new delta static.log7 194 200 +6 log8 190 193 +3 log5 190 193 +3 syslog_level 1 - -1 bb_verror_msg 583 581 -2 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 3/1 up/down: 12/-48) Total: -36 bytes Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-12 22:31:51 +05:30
bb_info_msg("received %s", "SIGTERM");
write_leases();
goto ret0;
2006-05-08 08:50:50 +05:30
}
udhcpd: fix "not dying on SIGTERM" Fixes: commit 52a515d18724bbb34e3ccbbb0218efcc4eccc0a8 "udhcp: use poll() instead of select()" Feb 16 2017 udhcp_sp_read() is meant to check whether signal pipe indeed has some data to read. In the above commit, it was changed as follows: - if (!FD_ISSET(signal_pipe.rd, rfds)) + if (!pfds[0].revents) return 0; The problem is, the check was working for select() purely by accident. Caught signal interrupts select()/poll() syscalls, they return with EINTR (regardless of SA_RESTART flag in sigaction). _Then_ signal handler is invoked. IOW: they can't see any changes to fd state caused by signal haldler (in our case, signal handler makes signal pipe ready to be read). For select(), it means that rfds[] bit array is unmodified, bit of signal pipe's read fd is still set, and the above check "works": it thinks select() says there is data to read. This accident does not work for poll(): .revents stays clear, and we do not try reading signal pipe as we should. In udhcpd, we fall through and block in socket read. Further SIGTERM signals simply cause socket read to be interrupted and then restarted (since SIGTERM handler has SA_RESTART=1). Fixing this as follows: remove the check altogether. Set signal pipe read fd to nonblocking mode. Always read it in udhcp_sp_read(). If read fails, assume it's EAGAIN and return 0 ("no signal seen"). udhcpd avoids reading signal pipe on every recvd packet by looping if EINTR (using safe_poll()) - thus ensuring we have correct .revents for all fds - and calling udhcp_sp_read() only if pfds[0].revents!=0. udhcpc performs much fewer reads (typically it sleeps >99.999% of the time), there is no need to optimize it: can call udhcp_sp_read() after each poll unconditionally. To robustify socket reads, unconditionally set pfds[1].revents=0 in udhcp_sp_fd_set() (which is before poll), and check it before reading network socket in udhcpd. TODO: This might still fail: if pfds[1].revents=POLLIN, socket read may still block. There are rare cases when select/poll indicates that data can be read, but then actual read still blocks (one such case is UDP packets with wrong checksum). General advise is, if you use a poll/select loop, keep all your fds nonblocking. Maybe we should also do that to our network sockets? function old new delta udhcp_sp_setup 55 65 +10 udhcp_sp_fd_set 54 60 +6 udhcp_sp_read 46 36 -10 udhcpd_main 1451 1437 -14 udhcpc_main 2723 2708 -15 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/3 up/down: 16/-39) Total: -23 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2018-03-10 23:31:48 +05:30
/* Is it a packet? */
if (!pfds[1].revents)
continue; /* no */
/* Note: we do not block here, we block on poll() instead.
* Blocking here would prevent SIGTERM from working:
* socket read inside this call is restarted on caught signals.
*/
bytes = udhcp_recv_kernel_packet(&packet, server_socket);
if (bytes < 0) {
/* bytes can also be -2 ("bad packet data") */
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if (bytes == -1 && errno != EINTR) {
log1("read error: "STRERROR_FMT", reopening socket" STRERROR_ERRNO);
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close(server_socket);
server_socket = -1;
}
continue;
}
if (packet.hlen != 6) {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_info_msg("MAC length != 6%s", ", ignoring packet");
continue;
}
if (packet.op != BOOTREQUEST) {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_info_msg("not a REQUEST%s", ", ignoring packet");
continue;
}
msg_type = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
if (!msg_type || msg_type[0] < DHCP_MINTYPE || msg_type[0] > DHCP_MAXTYPE) {
libbb: reduce the overhead of single parameter bb_error_msg() calls Back in 2007, commit 0c97c9d43707 ("'simple' error message functions by Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower overhead call to bb_perror_msg() when only a string was being printed with no parameters. This saves space for some CPU architectures because it avoids the overhead of a call to a variadic function. However there has never been a simple version of bb_error_msg(), and since 2007 many new calls to bb_perror_msg() have been added that only take a single parameter and so could have been using bb_simple_perror_message(). This changeset introduces 'simple' versions of bb_info_msg(), bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and bb_herror_msg_and_die(), and replaces all calls that only take a single parameter, or use something like ("%s", arg), with calls to the corresponding 'simple' version. Since it is likely that single parameter calls to the variadic functions may be accidentally reintroduced in the future a new debugging config option WARN_SIMPLE_MSG has been introduced. This uses some macro magic which will cause any such calls to generate a warning, but this is turned off by default to avoid use of the unpleasant macros in normal circumstances. This is a large changeset due to the number of calls that have been replaced. The only files that contain changes other than simple substitution of function calls are libbb.h, libbb/herror_msg.c, libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c, networking/udhcp/common.h and util-linux/mdev.c additonal macros have been added for logging so that single parameter and multiple parameter logging variants exist. The amount of space saved varies considerably by architecture, and was found to be as follows (for 'defconfig' using GCC 7.4): Arm: -92 bytes MIPS: -52 bytes PPC: -1836 bytes x86_64: -938 bytes Note that for the MIPS architecture only an exception had to be made disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h) because it made these files larger on MIPS. Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-07-02 15:05:03 +05:30
bb_info_msg("no or bad message type option%s", ", ignoring packet");
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continue;
}
/* Get SERVER_ID if present */
server_id_opt = udhcp_get_option32(&packet, DHCP_SERVER_ID);
if (server_id_opt) {
uint32_t server_id_network_order;
move_from_unaligned32(server_id_network_order, server_id_opt);
if (server_id_network_order != server_data.server_nip) {
/* client talks to somebody else */
log1("server ID doesn't match%s", ", ignoring packet");
continue;
}
}
/* Look for a static/dynamic lease */
static_lease_nip = get_static_nip_by_mac(&packet.chaddr);
if (static_lease_nip) {
Optionally re-introduce bb_info_msg() Between Busybox 1.24.2 and 1.25.0 the bb_info_msg() function was eliminated and calls to it changed to be bb_error_msg(). The downside of this is that daemons now log all messages to syslog at the LOG_ERR level which makes it hard to filter errors from informational messages. This change optionally re-introduces bb_info_msg(), controlled by a new option FEATURE_SYSLOG_INFO, restores all the calls to bb_info_msg() that were removed (only in applets that set logmode to LOGMODE_SYSLOG or LOGMODE_BOTH), and also changes informational messages in ifplugd and ntpd. The code size change of this is as follows (using 'defconfig' on x86_64 with gcc 7.3.0-27ubuntu1~18.04) function old new delta bb_info_msg - 182 +182 bb_vinfo_msg - 27 +27 static.log7 194 198 +4 log8 190 191 +1 log5 190 191 +1 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 3/0 up/down: 215/-45) Total: 170 bytes If you don't care about everything being logged at LOG_ERR level then when FEATURE_SYSLOG_INFO is disabled Busybox actually gets smaller: function old new delta static.log7 194 200 +6 log8 190 193 +3 log5 190 193 +3 syslog_level 1 - -1 bb_verror_msg 583 581 -2 crondlog 45 - -45 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 3/1 up/down: 12/-48) Total: -36 bytes Signed-off-by: James Byrne <james.byrne@origamienergy.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-04-12 22:31:51 +05:30
bb_info_msg("found static lease: %x", static_lease_nip);
memcpy(&fake_lease.lease_mac, &packet.chaddr, 6);
fake_lease.lease_nip = static_lease_nip;
fake_lease.expires = 0;
lease = &fake_lease;
} else {
lease = find_lease_by_mac(packet.chaddr);
2006-05-08 08:50:50 +05:30
}
/* Get REQUESTED_IP if present */
requested_nip = 0;
requested_ip_opt = udhcp_get_option32(&packet, DHCP_REQUESTED_IP);
if (requested_ip_opt) {
move_from_unaligned32(requested_nip, requested_ip_opt);
}
switch (msg_type[0]) {
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case DHCPDISCOVER:
log1("received %s", "DISCOVER");
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send_offer(&packet, static_lease_nip, lease, requested_nip, arpping_ms);
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break;
case DHCPREQUEST:
log1("received %s", "REQUEST");
/* RFC 2131:
o DHCPREQUEST generated during SELECTING state:
Client inserts the address of the selected server in 'server
identifier', 'ciaddr' MUST be zero, 'requested IP address' MUST be
filled in with the yiaddr value from the chosen DHCPOFFER.
Note that the client may choose to collect several DHCPOFFER
messages and select the "best" offer. The client indicates its
selection by identifying the offering server in the DHCPREQUEST
message. If the client receives no acceptable offers, the client
may choose to try another DHCPDISCOVER message. Therefore, the
servers may not receive a specific DHCPREQUEST from which they can
decide whether or not the client has accepted the offer.
o DHCPREQUEST generated during INIT-REBOOT state:
'server identifier' MUST NOT be filled in, 'requested IP address'
option MUST be filled in with client's notion of its previously
assigned address. 'ciaddr' MUST be zero. The client is seeking to
verify a previously allocated, cached configuration. Server SHOULD
send a DHCPNAK message to the client if the 'requested IP address'
is incorrect, or is on the wrong network.
Determining whether a client in the INIT-REBOOT state is on the
correct network is done by examining the contents of 'giaddr', the
'requested IP address' option, and a database lookup. If the DHCP
server detects that the client is on the wrong net (i.e., the
result of applying the local subnet mask or remote subnet mask (if
'giaddr' is not zero) to 'requested IP address' option value
doesn't match reality), then the server SHOULD send a DHCPNAK
message to the client.
If the network is correct, then the DHCP server should check if
the client's notion of its IP address is correct. If not, then the
server SHOULD send a DHCPNAK message to the client. If the DHCP
server has no record of this client, then it MUST remain silent,
and MAY output a warning to the network administrator. This
behavior is necessary for peaceful coexistence of non-
communicating DHCP servers on the same wire.
If 'giaddr' is 0x0 in the DHCPREQUEST message, the client is on
the same subnet as the server. The server MUST broadcast the
DHCPNAK message to the 0xffffffff broadcast address because the
client may not have a correct network address or subnet mask, and
the client may not be answering ARP requests.
If 'giaddr' is set in the DHCPREQUEST message, the client is on a
different subnet. The server MUST set the broadcast bit in the
DHCPNAK, so that the relay agent will broadcast the DHCPNAK to the
client, because the client may not have a correct network address
or subnet mask, and the client may not be answering ARP requests.
o DHCPREQUEST generated during RENEWING state:
'server identifier' MUST NOT be filled in, 'requested IP address'
option MUST NOT be filled in, 'ciaddr' MUST be filled in with
client's IP address. In this situation, the client is completely
configured, and is trying to extend its lease. This message will
be unicast, so no relay agents will be involved in its
transmission. Because 'giaddr' is therefore not filled in, the
DHCP server will trust the value in 'ciaddr', and use it when
replying to the client.
A client MAY choose to renew or extend its lease prior to T1. The
server may choose not to extend the lease (as a policy decision by
the network administrator), but should return a DHCPACK message
regardless.
o DHCPREQUEST generated during REBINDING state:
'server identifier' MUST NOT be filled in, 'requested IP address'
option MUST NOT be filled in, 'ciaddr' MUST be filled in with
client's IP address. In this situation, the client is completely
configured, and is trying to extend its lease. This message MUST
be broadcast to the 0xffffffff IP broadcast address. The DHCP
server SHOULD check 'ciaddr' for correctness before replying to
the DHCPREQUEST.
The DHCPREQUEST from a REBINDING client is intended to accommodate
sites that have multiple DHCP servers and a mechanism for
maintaining consistency among leases managed by multiple servers.
A DHCP server MAY extend a client's lease only if it has local
administrative authority to do so.
*/
if (!requested_ip_opt) {
requested_nip = packet.ciaddr;
if (requested_nip == 0) {
log1("no requested IP and no ciaddr%s", ", ignoring packet");
break;
}
}
if (lease && requested_nip == lease->lease_nip) {
/* client requested or configured IP matches the lease.
* ACK it, and bump lease expiration time. */
send_ACK(&packet, lease->lease_nip);
break;
}
/* No lease for this MAC, or lease IP != requested IP */
if (server_id_opt /* client is in SELECTING state */
|| requested_ip_opt /* client is in INIT-REBOOT state */
) {
/* "No, we don't have this IP for you" */
send_NAK(&packet);
} /* else: client is in RENEWING or REBINDING, do not answer */
2006-05-08 08:50:50 +05:30
break;
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case DHCPDECLINE:
/* RFC 2131:
* "If the server receives a DHCPDECLINE message,
* the client has discovered through some other means
* that the suggested network address is already
* in use. The server MUST mark the network address
* as not available and SHOULD notify the local
* sysadmin of a possible configuration problem."
*
* SERVER_ID must be present,
* REQUESTED_IP must be present,
* chaddr must be filled in,
* ciaddr must be 0 (we do not check this)
*/
log1("received %s", "DECLINE");
if (server_id_opt
&& requested_ip_opt
&& lease /* chaddr matches this lease */
&& requested_nip == lease->lease_nip
) {
memset(lease->lease_mac, 0, sizeof(lease->lease_mac));
lease->expires = time(NULL) + server_data.decline_time;
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}
break;
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case DHCPRELEASE:
/* "Upon receipt of a DHCPRELEASE message, the server
* marks the network address as not allocated."
*
* SERVER_ID must be present,
* REQUESTED_IP must not be present (we do not check this),
* chaddr must be filled in,
* ciaddr must be filled in
*/
log1("received %s", "RELEASE");
if (server_id_opt
&& lease /* chaddr matches this lease */
&& packet.ciaddr == lease->lease_nip
) {
lease->expires = time(NULL);
}
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break;
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case DHCPINFORM:
log1("received %s", "INFORM");
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send_inform(&packet);
break;
}
}
ret0:
retval = 0;
ret:
/*if (server_data.pidfile) - server_data.pidfile is never NULL */
remove_pidfile(server_data.pidfile);
return retval;
2006-05-08 08:50:50 +05:30
}