busybox/networking/udhcp/dhcpc.c

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/* vi: set sw=4 ts=4: */
/*
* udhcp client
2006-05-08 08:50:50 +05:30
* 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_UDHCPC(APPLET(udhcpc, BB_DIR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_UDHCPC) += common.o packet.o signalpipe.o socket.o
//kbuild:lib-$(CONFIG_UDHCPC) += dhcpc.o
//kbuild:lib-$(CONFIG_FEATURE_UDHCPC_ARPING) += arpping.o
//kbuild:lib-$(CONFIG_FEATURE_UDHCP_RFC3397) += domain_codec.o
#include <syslog.h>
/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
#define WANT_PIDFILE 1
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#include "common.h"
#include "dhcpd.h"
#include "dhcpc.h"
#include <netinet/if_ether.h>
#include <linux/filter.h>
#include <linux/if_packet.h>
#ifndef PACKET_AUXDATA
# define PACKET_AUXDATA 8
struct tpacket_auxdata {
uint32_t tp_status;
uint32_t tp_len;
uint32_t tp_snaplen;
uint16_t tp_mac;
uint16_t tp_net;
uint16_t tp_vlan_tci;
uint16_t tp_padding;
};
#endif
/* "struct client_config_t client_config" is in bb_common_bufsiz1 */
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#if ENABLE_LONG_OPTS
static const char udhcpc_longopts[] ALIGN1 =
"clientid-none\0" No_argument "C"
"vendorclass\0" Required_argument "V"
"hostname\0" Required_argument "H"
"fqdn\0" Required_argument "F"
"interface\0" Required_argument "i"
"now\0" No_argument "n"
"pidfile\0" Required_argument "p"
"quit\0" No_argument "q"
"release\0" No_argument "R"
"request\0" Required_argument "r"
"script\0" Required_argument "s"
"timeout\0" Required_argument "T"
"retries\0" Required_argument "t"
"tryagain\0" Required_argument "A"
"syslog\0" No_argument "S"
"request-option\0" Required_argument "O"
"no-default-options\0" No_argument "o"
"foreground\0" No_argument "f"
USE_FOR_MMU(
"background\0" No_argument "b"
)
"broadcast\0" No_argument "B"
IF_FEATURE_UDHCPC_ARPING("arping\0" Optional_argument "a")
IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
;
#endif
/* Must match getopt32 option string order */
enum {
OPT_C = 1 << 0,
OPT_V = 1 << 1,
OPT_H = 1 << 2,
OPT_h = 1 << 3,
OPT_F = 1 << 4,
OPT_i = 1 << 5,
OPT_n = 1 << 6,
OPT_p = 1 << 7,
OPT_q = 1 << 8,
OPT_R = 1 << 9,
OPT_r = 1 << 10,
OPT_s = 1 << 11,
OPT_T = 1 << 12,
OPT_t = 1 << 13,
OPT_S = 1 << 14,
OPT_A = 1 << 15,
OPT_O = 1 << 16,
OPT_o = 1 << 17,
OPT_x = 1 << 18,
OPT_f = 1 << 19,
OPT_B = 1 << 20,
/* The rest has variable bit positions, need to be clever */
OPTBIT_B = 20,
USE_FOR_MMU( OPTBIT_b,)
IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
};
/*** Script execution code ***/
/* get a rough idea of how long an option will be (rounding up...) */
static const uint8_t len_of_option_as_string[] ALIGN1 = {
[OPTION_IP ] = sizeof("255.255.255.255 "),
[OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
[OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
[OPTION_6RD ] = sizeof("132 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "),
[OPTION_STRING ] = 1,
[OPTION_STRING_HOST ] = 1,
#if ENABLE_FEATURE_UDHCP_RFC3397
[OPTION_DNS_STRING ] = 1, /* unused */
/* Hmmm, this severely overestimates size if SIP_SERVERS option
* is in domain name form: N-byte option in binary form
* mallocs ~16*N bytes. But it is freed almost at once.
*/
[OPTION_SIP_SERVERS ] = sizeof("255.255.255.255 "),
#endif
// [OPTION_BOOLEAN ] = sizeof("yes "),
[OPTION_U8 ] = sizeof("255 "),
[OPTION_U16 ] = sizeof("65535 "),
// [OPTION_S16 ] = sizeof("-32768 "),
[OPTION_U32 ] = sizeof("4294967295 "),
[OPTION_S32 ] = sizeof("-2147483684 "),
};
/* note: ip is a pointer to an IP in network order, possibly misaliged */
static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
{
return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
}
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/* really simple implementation, just count the bits */
static int mton(uint32_t mask)
{
int i = 0;
mask = ntohl(mask); /* 111110000-like bit pattern */
while (mask) {
i++;
mask <<= 1;
}
return i;
}
#if ENABLE_FEATURE_UDHCPC_SANITIZEOPT
/* Check if a given label represents a valid DNS label
* Return pointer to the first character after the label
* (NUL or dot) upon success, NULL otherwise.
* See RFC1035, 2.3.1
*/
/* We don't need to be particularly anal. For example, allowing _, hyphen
* at the end, or leading and trailing dots would be ok, since it
* can't be used for attacks. (Leading hyphen can be, if someone uses
* cmd "$hostname"
* in the script: then hostname may be treated as an option)
*/
static const char *valid_domain_label(const char *label)
{
unsigned char ch;
//unsigned pos = 0;
if (label[0] == '-')
return NULL;
for (;;) {
ch = *label;
if ((ch|0x20) < 'a' || (ch|0x20) > 'z') {
if (ch < '0' || ch > '9') {
if (ch == '\0' || ch == '.')
return label;
/* DNS allows only '-', but we are more permissive */
if (ch != '-' && ch != '_')
return NULL;
}
}
label++;
//pos++;
//Do we want this?
//if (pos > 63) /* NS_MAXLABEL; labels must be 63 chars or less */
// return NULL;
}
}
/* Check if a given name represents a valid DNS name */
/* See RFC1035, 2.3.1 */
static int good_hostname(const char *name)
{
//const char *start = name;
for (;;) {
name = valid_domain_label(name);
if (!name)
return 0;
if (!name[0])
return 1;
//Do we want this?
//return ((name - start) < 1025); /* NS_MAXDNAME */
name++;
if (*name == '\0')
return 1; // We allow trailing dot too
}
}
#else
# define good_hostname(name) 1
#endif
/* Create "opt_name=opt_value" string */
static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
{
unsigned upper_length;
int len, type, optlen;
char *dest, *ret;
/* option points to OPT_DATA, need to go back to get OPT_LEN */
len = option[-OPT_DATA + OPT_LEN];
type = optflag->flags & OPTION_TYPE_MASK;
optlen = dhcp_option_lengths[type];
upper_length = len_of_option_as_string[type]
* ((unsigned)(len + optlen) / (unsigned)optlen);
dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
dest += sprintf(ret, "%s=", opt_name);
while (len >= optlen) {
switch (type) {
case OPTION_IP:
case OPTION_IP_PAIR:
dest += sprint_nip(dest, "", option);
if (type == OPTION_IP)
break;
dest += sprint_nip(dest, "/", option + 4);
break;
// case OPTION_BOOLEAN:
// dest += sprintf(dest, *option ? "yes" : "no");
// break;
case OPTION_U8:
dest += sprintf(dest, "%u", *option);
break;
// case OPTION_S16:
case OPTION_U16: {
uint16_t val_u16;
move_from_unaligned16(val_u16, option);
dest += sprintf(dest, "%u", ntohs(val_u16));
break;
}
case OPTION_S32:
case OPTION_U32: {
uint32_t val_u32;
move_from_unaligned32(val_u32, option);
dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
break;
}
/* Note: options which use 'return' instead of 'break'
* (for example, OPTION_STRING) skip the code which handles
* the case of list of options.
*/
case OPTION_STRING:
case OPTION_STRING_HOST:
memcpy(dest, option, len);
dest[len] = '\0';
//TODO: it appears option 15 DHCP_DOMAIN_NAME is often abused
//by DHCP admins to contain a space-separated list of domains,
//not one domain name (presumably, to work as list of search domains,
//instead of using proper option 119 DHCP_DOMAIN_SEARCH).
//Currently, good_hostname() balks on strings containing spaces.
//Do we need to allow it? Only for DHCP_DOMAIN_NAME option?
if (type == OPTION_STRING_HOST && !good_hostname(dest))
safe_strncpy(dest, "bad", len);
return ret;
case OPTION_STATIC_ROUTES: {
/* Option binary format:
* mask [one byte, 0..32]
* ip [big endian, 0..4 bytes depending on mask]
* router [big endian, 4 bytes]
* may be repeated
*
* We convert it to a string "IP/MASK ROUTER IP2/MASK2 ROUTER2"
*/
const char *pfx = "";
while (len >= 1 + 4) { /* mask + 0-byte ip + router */
uint32_t nip;
uint8_t *p;
unsigned mask;
int bytes;
mask = *option++;
if (mask > 32)
break;
len--;
nip = 0;
p = (void*) &nip;
bytes = (mask + 7) / 8; /* 0 -> 0, 1..8 -> 1, 9..16 -> 2 etc */
while (--bytes >= 0) {
*p++ = *option++;
len--;
}
if (len < 4)
break;
/* print ip/mask */
dest += sprint_nip(dest, pfx, (void*) &nip);
pfx = " ";
dest += sprintf(dest, "/%u ", mask);
/* print router */
dest += sprint_nip(dest, "", option);
option += 4;
len -= 4;
}
return ret;
}
case OPTION_6RD:
/* Option binary format (see RFC 5969):
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | 6rdPrefix |
* ... (16 octets) ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* ... 6rdBRIPv4Address(es) ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* We convert it to a string
* "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..."
*
* Sanity check: ensure that our length is at least 22 bytes, that
* IPv4MaskLen <= 32,
* 6rdPrefixLen <= 128,
* 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
* (2nd condition need no check - it follows from 1st and 3rd).
* Else, return envvar with empty value ("optname=")
*/
if (len >= (1 + 1 + 16 + 4)
&& option[0] <= 32
&& (option[1] + 32 - option[0]) <= 128
) {
/* IPv4MaskLen */
dest += sprintf(dest, "%u ", *option++);
/* 6rdPrefixLen */
dest += sprintf(dest, "%u ", *option++);
/* 6rdPrefix */
dest += sprint_nip6(dest, /* "", */ option);
option += 16;
len -= 1 + 1 + 16 + 4;
/* "+ 4" above corresponds to the length of IPv4 addr
* we consume in the loop below */
while (1) {
/* 6rdBRIPv4Address(es) */
dest += sprint_nip(dest, " ", option);
option += 4;
len -= 4; /* do we have yet another 4+ bytes? */
if (len < 0)
break; /* no */
}
}
return ret;
#if ENABLE_FEATURE_UDHCP_RFC3397
case OPTION_DNS_STRING:
/* unpack option into dest; use ret for prefix (i.e., "optname=") */
dest = dname_dec(option, len, ret);
if (dest) {
free(ret);
return dest;
}
/* error. return "optname=" string */
return ret;
case OPTION_SIP_SERVERS:
/* Option binary format:
* type: byte
* type=0: domain names, dns-compressed
* type=1: IP addrs
*/
option++;
len--;
if (option[-1] == 0) {
dest = dname_dec(option, len, ret);
if (dest) {
free(ret);
return dest;
}
} else
if (option[-1] == 1) {
const char *pfx = "";
while (1) {
len -= 4;
if (len < 0)
break;
dest += sprint_nip(dest, pfx, option);
pfx = " ";
option += 4;
}
}
return ret;
#endif
} /* switch */
/* If we are here, try to format any remaining data
* in the option as another, similarly-formatted option
*/
option += optlen;
len -= optlen;
// TODO: it can be a list only if (optflag->flags & OPTION_LIST).
// Should we bail out/warn if we see multi-ip option which is
// not allowed to be such (for example, DHCP_BROADCAST)? -
if (len < optlen /* || !(optflag->flags & OPTION_LIST) */)
break;
*dest++ = ' ';
*dest = '\0';
} /* while */
return ret;
}
/* put all the parameters into the environment */
static char **fill_envp(struct dhcp_packet *packet)
{
int envc;
int i;
char **envp, **curr;
const char *opt_name;
uint8_t *temp;
uint8_t overload = 0;
#define BITMAP unsigned
#define BBITS (sizeof(BITMAP) * 8)
#define BMASK(i) (1 << (i & (sizeof(BITMAP) * 8 - 1)))
#define FOUND_OPTS(i) (found_opts[(unsigned)i / BBITS])
BITMAP found_opts[256 / BBITS];
memset(found_opts, 0, sizeof(found_opts));
/* We need 6 elements for:
* "interface=IFACE"
* "ip=N.N.N.N" from packet->yiaddr
* "siaddr=IP" from packet->siaddr_nip (unless 0)
* "boot_file=FILE" from packet->file (unless overloaded)
* "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
* terminating NULL
*/
envc = 6;
/* +1 element for each option, +2 for subnet option: */
if (packet) {
/* note: do not search for "pad" (0) and "end" (255) options */
//TODO: change logic to scan packet _once_
for (i = 1; i < 255; i++) {
temp = udhcp_get_option(packet, i);
if (temp) {
if (i == DHCP_OPTION_OVERLOAD)
overload |= *temp;
else if (i == DHCP_SUBNET)
envc++; /* for $mask */
envc++;
/*if (i != DHCP_MESSAGE_TYPE)*/
FOUND_OPTS(i) |= BMASK(i);
}
}
}
curr = envp = xzalloc(sizeof(envp[0]) * envc);
*curr = xasprintf("interface=%s", client_config.interface);
putenv(*curr++);
if (!packet)
return envp;
/* Export BOOTP fields. Fields we don't (yet?) export:
* uint8_t op; // always BOOTREPLY
* uint8_t htype; // hardware address type. 1 = 10mb ethernet
* uint8_t hlen; // hardware address length
* uint8_t hops; // used by relay agents only
* uint32_t xid;
* uint16_t secs; // elapsed since client began acquisition/renewal
* uint16_t flags; // only one flag so far: bcast. Never set by server
* uint32_t ciaddr; // client IP (usually == yiaddr. can it be different
* // if during renew server wants to give us different IP?)
* uint32_t gateway_nip; // relay agent IP address
* uint8_t chaddr[16]; // link-layer client hardware address (MAC)
* TODO: export gateway_nip as $giaddr?
*/
/* Most important one: yiaddr as $ip */
*curr = xmalloc(sizeof("ip=255.255.255.255"));
sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
putenv(*curr++);
if (packet->siaddr_nip) {
/* IP address of next server to use in bootstrap */
*curr = xmalloc(sizeof("siaddr=255.255.255.255"));
sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
putenv(*curr++);
}
if (!(overload & FILE_FIELD) && packet->file[0]) {
/* watch out for invalid packets */
*curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
putenv(*curr++);
}
if (!(overload & SNAME_FIELD) && packet->sname[0]) {
/* watch out for invalid packets */
*curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
putenv(*curr++);
}
/* Export known DHCP options */
opt_name = dhcp_option_strings;
i = 0;
while (*opt_name) {
uint8_t code = dhcp_optflags[i].code;
BITMAP *found_ptr = &FOUND_OPTS(code);
BITMAP found_mask = BMASK(code);
if (!(*found_ptr & found_mask))
goto next;
*found_ptr &= ~found_mask; /* leave only unknown options */
temp = udhcp_get_option(packet, code);
*curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
putenv(*curr++);
if (code == DHCP_SUBNET) {
/* Subnet option: make things like "$ip/$mask" possible */
uint32_t subnet;
move_from_unaligned32(subnet, temp);
*curr = xasprintf("mask=%u", mton(subnet));
putenv(*curr++);
}
next:
opt_name += strlen(opt_name) + 1;
i++;
}
/* Export unknown options */
for (i = 0; i < 256;) {
BITMAP bitmap = FOUND_OPTS(i);
if (!bitmap) {
i += BBITS;
continue;
}
if (bitmap & BMASK(i)) {
unsigned len, ofs;
temp = udhcp_get_option(packet, i);
/* udhcp_get_option returns ptr to data portion,
* need to go back to get len
*/
len = temp[-OPT_DATA + OPT_LEN];
*curr = xmalloc(sizeof("optNNN=") + 1 + len*2);
ofs = sprintf(*curr, "opt%u=", i);
*bin2hex(*curr + ofs, (void*) temp, len) = '\0';
putenv(*curr++);
}
i++;
}
return envp;
}
/* Call a script with a par file and env vars */
static void udhcp_run_script(struct dhcp_packet *packet, const char *name)
{
char **envp, **curr;
char *argv[3];
envp = fill_envp(packet);
/* call script */
log1("executing %s %s", client_config.script, name);
argv[0] = (char*) client_config.script;
argv[1] = (char*) name;
argv[2] = NULL;
spawn_and_wait(argv);
for (curr = envp; *curr; curr++) {
log2(" %s", *curr);
bb_unsetenv_and_free(*curr);
}
free(envp);
}
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/*** Sending/receiving packets ***/
static ALWAYS_INLINE uint32_t random_xid(void)
{
return rand();
}
/* Initialize the packet with the proper defaults */
static void init_packet(struct dhcp_packet *packet, char type)
{
uint16_t secs;
/* Fill in: op, htype, hlen, cookie fields; message type option: */
udhcp_init_header(packet, type);
packet->xid = random_xid();
client_config.last_secs = monotonic_sec();
if (client_config.first_secs == 0)
client_config.first_secs = client_config.last_secs;
secs = client_config.last_secs - client_config.first_secs;
packet->secs = htons(secs);
memcpy(packet->chaddr, client_config.client_mac, 6);
if (client_config.clientid)
udhcp_add_binary_option(packet, client_config.clientid);
}
static void add_client_options(struct dhcp_packet *packet)
{
int i, end, len;
udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE));
/* Add a "param req" option with the list of options we'd like to have
* from stubborn DHCP servers. Pull the data from the struct in common.c.
* No bounds checking because it goes towards the head of the packet. */
end = udhcp_end_option(packet->options);
len = 0;
for (i = 1; i < DHCP_END; i++) {
if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) {
packet->options[end + OPT_DATA + len] = i;
len++;
}
}
if (len) {
packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
packet->options[end + OPT_LEN] = len;
packet->options[end + OPT_DATA + len] = DHCP_END;
}
if (client_config.vendorclass)
udhcp_add_binary_option(packet, client_config.vendorclass);
if (client_config.hostname)
udhcp_add_binary_option(packet, client_config.hostname);
if (client_config.fqdn)
udhcp_add_binary_option(packet, client_config.fqdn);
/* Request broadcast replies if we have no IP addr */
if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
packet->flags |= htons(BROADCAST_FLAG);
/* Add -x options if any */
{
struct option_set *curr = client_config.options;
while (curr) {
udhcp_add_binary_option(packet, curr->data);
curr = curr->next;
}
// if (client_config.sname)
// strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
// if (client_config.boot_file)
// strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
}
// This will be needed if we remove -V VENDOR_STR in favor of
// -x vendor:VENDOR_STR
//if (!udhcp_find_option(packet.options, DHCP_VENDOR))
// /* not set, set the default vendor ID */
// ...add (DHCP_VENDOR, "udhcp "BB_VER) opt...
}
/* RFC 2131
* 4.4.4 Use of broadcast and unicast
*
* The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
* messages, unless the client knows the address of a DHCP server.
* The client unicasts DHCPRELEASE messages to the server. Because
* the client is declining the use of the IP address supplied by the server,
* the client broadcasts DHCPDECLINE messages.
*
* When the DHCP client knows the address of a DHCP server, in either
* INIT or REBOOTING state, the client may use that address
* in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
* The client may also use unicast to send DHCPINFORM messages
* to a known DHCP server. If the client receives no response to DHCP
* messages sent to the IP address of a known DHCP server, the DHCP
* client reverts to using the IP broadcast address.
*/
static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet, uint32_t src_nip)
{
return udhcp_send_raw_packet(packet,
/*src*/ src_nip, CLIENT_PORT,
/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
client_config.ifindex);
}
static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t server)
{
if (server)
return udhcp_send_kernel_packet(packet,
ciaddr, CLIENT_PORT,
server, SERVER_PORT);
return raw_bcast_from_client_config_ifindex(packet, ciaddr);
}
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
/* NOINLINE: limit stack usage in caller */
static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
{
struct dhcp_packet packet;
/* Fill in: op, htype, hlen, cookie, chaddr fields,
* random xid field (we override it below),
* client-id option (unless -C), message type option:
*/
init_packet(&packet, DHCPDISCOVER);
packet.xid = xid;
if (requested)
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
/* Add options: maxsize,
* optionally: hostname, fqdn, vendorclass,
* "param req" option according to -O, options specified with -x
*/
add_client_options(&packet);
bb_error_msg("sending %s", "discover");
return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
}
/* Broadcast a DHCP request message */
/* RFC 2131 3.1 paragraph 3:
* "The client _broadcasts_ a DHCPREQUEST message..."
*/
/* NOINLINE: limit stack usage in caller */
static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
struct in_addr temp_addr;
/*
* RFC 2131 4.3.2 DHCPREQUEST message
* ...
* If the DHCPREQUEST message contains a 'server identifier'
* option, the message is in response to a DHCPOFFER message.
* Otherwise, the message is a request to verify or extend an
* existing lease. If the client uses a 'client identifier'
* in a DHCPREQUEST message, it MUST use that same 'client identifier'
* in all subsequent messages. If the client included a list
* of requested parameters in a DHCPDISCOVER message, it MUST
* include that list in all subsequent messages.
*/
/* Fill in: op, htype, hlen, cookie, chaddr fields,
* random xid field (we override it below),
* client-id option (unless -C), message type option:
*/
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
/* Add options: maxsize,
* optionally: hostname, fqdn, vendorclass,
* "param req" option according to -O, and options specified with -x
*/
add_client_options(&packet);
temp_addr.s_addr = requested;
bb_error_msg("sending select for %s", inet_ntoa(temp_addr));
return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
}
/* Unicast or broadcast a DHCP renew message */
/* NOINLINE: limit stack usage in caller */
static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
struct in_addr temp_addr;
/*
* RFC 2131 4.3.2 DHCPREQUEST message
* ...
* 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.
*/
/* Fill in: op, htype, hlen, cookie, chaddr fields,
* random xid field (we override it below),
* client-id option (unless -C), message type option:
*/
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
packet.ciaddr = ciaddr;
/* Add options: maxsize,
* optionally: hostname, fqdn, vendorclass,
* "param req" option according to -O, and options specified with -x
*/
add_client_options(&packet);
temp_addr.s_addr = server;
bb_error_msg("sending renew to %s", inet_ntoa(temp_addr));
return bcast_or_ucast(&packet, ciaddr, server);
}
#if ENABLE_FEATURE_UDHCPC_ARPING
/* Broadcast a DHCP decline message */
/* NOINLINE: limit stack usage in caller */
static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
/* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
* client-id option (unless -C), message type option:
*/
init_packet(&packet, DHCPDECLINE);
#if 0
/* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
* but in case the server is buggy and wants DHCPDECLINE's xid
* to match the xid which started entire handshake,
* we use the same xid we used in initial DHCPDISCOVER:
*/
packet.xid = xid;
#endif
/* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
bb_error_msg("sending %s", "decline");
return raw_bcast_from_client_config_ifindex(&packet, INADDR_ANY);
}
#endif
/* Unicast a DHCP release message */
static int send_release(uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
/* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
* client-id option (unless -C), message type option:
*/
init_packet(&packet, DHCPRELEASE);
/* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */
packet.ciaddr = ciaddr;
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
bb_error_msg("sending %s", "release");
/* Note: normally we unicast here since "server" is not zero.
* However, there _are_ people who run "address-less" DHCP servers,
* and reportedly ISC dhcp client and Windows allow that.
*/
return bcast_or_ucast(&packet, ciaddr, server);
}
/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
/* NOINLINE: limit stack usage in caller */
static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
{
int bytes;
struct ip_udp_dhcp_packet packet;
uint16_t check;
unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
struct iovec iov;
struct msghdr msg;
struct cmsghdr *cmsg;
/* used to use just safe_read(fd, &packet, sizeof(packet))
* but we need to check for TP_STATUS_CSUMNOTREADY :(
*/
iov.iov_base = &packet;
iov.iov_len = sizeof(packet);
memset(&msg, 0, sizeof(msg));
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = cmsgbuf;
msg.msg_controllen = sizeof(cmsgbuf);
for (;;) {
bytes = recvmsg(fd, &msg, 0);
if (bytes < 0) {
if (errno == EINTR)
continue;
log1("packet read error, ignoring");
/* NB: possible down interface, etc. Caller should pause. */
return bytes; /* returns -1 */
}
break;
}
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
log1("packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
/* packet is bigger than sizeof(packet), we did partial read */
log1("oversized packet, ignoring");
return -2;
}
/* ignore any extra garbage bytes */
bytes = ntohs(packet.ip.tot_len);
/* make sure its the right packet for us, and that it passes sanity checks */
if (packet.ip.protocol != IPPROTO_UDP
|| packet.ip.version != IPVERSION
|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
|| packet.udp.dest != htons(CLIENT_PORT)
/* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
log1("unrelated/bogus packet, ignoring");
return -2;
}
/* verify IP checksum */
check = packet.ip.check;
packet.ip.check = 0;
if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) {
log1("bad IP header checksum, ignoring");
return -2;
}
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_PACKET
&& cmsg->cmsg_type == PACKET_AUXDATA
) {
/* some VMs don't checksum UDP and TCP data
* they send to the same physical machine,
* here we detect this case:
*/
struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
if (aux->tp_status & TP_STATUS_CSUMNOTREADY)
goto skip_udp_sum_check;
}
}
/* verify UDP checksum. IP header has to be modified for this */
memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
/* ip.xx fields which are not memset: protocol, check, saddr, daddr */
packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
check = packet.udp.check;
packet.udp.check = 0;
if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
log1("packet with bad UDP checksum received, ignoring");
return -2;
}
skip_udp_sum_check:
if (packet.data.cookie != htonl(DHCP_MAGIC)) {
bb_error_msg("packet with bad magic, ignoring");
return -2;
}
log1("received %s", "a packet");
udhcp_dump_packet(&packet.data);
bytes -= sizeof(packet.ip) + sizeof(packet.udp);
memcpy(dhcp_pkt, &packet.data, bytes);
return bytes;
}
/*** Main ***/
static int sockfd = -1;
#define LISTEN_NONE 0
#define LISTEN_KERNEL 1
#define LISTEN_RAW 2
static smallint listen_mode;
/* initial state: (re)start DHCP negotiation */
#define INIT_SELECTING 0
/* discover was sent, DHCPOFFER reply received */
#define REQUESTING 1
/* select/renew was sent, DHCPACK reply received */
#define BOUND 2
/* half of lease passed, want to renew it by sending unicast renew requests */
#define RENEWING 3
/* renew requests were not answered, lease is almost over, send broadcast renew */
#define REBINDING 4
/* manually requested renew (SIGUSR1) */
#define RENEW_REQUESTED 5
/* release, possibly manually requested (SIGUSR2) */
#define RELEASED 6
static smallint state;
static int udhcp_raw_socket(int ifindex)
{
int fd;
struct sockaddr_ll sock;
log2("opening raw socket on ifindex %d", ifindex);
fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
/* ^^^^^
* SOCK_DGRAM: remove link-layer headers on input (SOCK_RAW keeps them)
* ETH_P_IP: want to receive only packets with IPv4 eth type
*/
log2("got raw socket fd");
memset(&sock, 0, sizeof(sock)); /* let's be deterministic */
sock.sll_family = AF_PACKET;
sock.sll_protocol = htons(ETH_P_IP);
sock.sll_ifindex = ifindex;
/*sock.sll_hatype = ARPHRD_???;*/
/*sock.sll_pkttype = PACKET_???;*/
/*sock.sll_halen = ???;*/
/*sock.sll_addr[8] = ???;*/
xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
#if 0 /* Several users reported breakage when BPF filter is used */
if (CLIENT_PORT == 68) {
/* Use only if standard port is in use */
/*
* I've selected not to see LL header, so BPF doesn't see it, too.
* The filter may also pass non-IP and non-ARP packets, but we do
* a more complete check when receiving the message in userspace.
*
* and filter shamelessly stolen from:
*
* http://www.flamewarmaster.de/software/dhcpclient/
*
* There are a few other interesting ideas on that page (look under
* "Motivation"). Use of netlink events is most interesting. Think
* of various network servers listening for events and reconfiguring.
* That would obsolete sending HUP signals and/or make use of restarts.
*
* Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
* License: GPL v2.
*/
static const struct sock_filter filter_instr[] = {
/* load 9th byte (protocol) */
BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
/* jump to L1 if it is IPPROTO_UDP, else to L4 */
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
/* L1: load halfword from offset 6 (flags and frag offset) */
BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
/* jump to L4 if any bits in frag offset field are set, else to L2 */
BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
/* L2: skip IP header (load index reg with header len) */
BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
/* load udp destination port from halfword[header_len + 2] */
BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
/* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
/* L3: accept packet ("accept 0x7fffffff bytes") */
/* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */
BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
/* L4: discard packet ("accept zero bytes") */
BPF_STMT(BPF_RET|BPF_K, 0),
};
static const struct sock_fprog filter_prog = {
.len = sizeof(filter_instr) / sizeof(filter_instr[0]),
/* casting const away: */
.filter = (struct sock_filter *) filter_instr,
};
/* Ignoring error (kernel may lack support for this) */
if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
sizeof(filter_prog)) >= 0)
log1("attached filter to raw socket fd"); // log?
}
#endif
if (setsockopt_1(fd, SOL_PACKET, PACKET_AUXDATA) != 0) {
if (errno != ENOPROTOOPT)
log1("can't set PACKET_AUXDATA on raw socket");
}
log1("created raw socket");
return fd;
}
static void change_listen_mode(int new_mode)
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{
log1("entering listen mode: %s",
new_mode != LISTEN_NONE
? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
: "none"
);
listen_mode = new_mode;
if (sockfd >= 0) {
close(sockfd);
sockfd = -1;
}
if (new_mode == LISTEN_KERNEL)
sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
else if (new_mode != LISTEN_NONE)
sockfd = udhcp_raw_socket(client_config.ifindex);
/* else LISTEN_NONE: sockfd stays closed */
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}
/* Called only on SIGUSR1 */
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static void perform_renew(void)
{
bb_error_msg("performing DHCP renew");
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switch (state) {
case BOUND:
change_listen_mode(LISTEN_KERNEL);
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case RENEWING:
case REBINDING:
state = RENEW_REQUESTED;
break;
case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
udhcp_run_script(NULL, "deconfig");
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case REQUESTING:
case RELEASED:
change_listen_mode(LISTEN_RAW);
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state = INIT_SELECTING;
break;
case INIT_SELECTING:
break;
}
}
static void perform_release(uint32_t server_addr, uint32_t requested_ip)
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{
char buffer[sizeof("255.255.255.255")];
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struct in_addr temp_addr;
/* send release packet */
if (state == BOUND
|| state == RENEWING
|| state == REBINDING
|| state == RENEW_REQUESTED
) {
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temp_addr.s_addr = server_addr;
strcpy(buffer, inet_ntoa(temp_addr));
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temp_addr.s_addr = requested_ip;
bb_error_msg("unicasting a release of %s to %s",
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inet_ntoa(temp_addr), buffer);
send_release(server_addr, requested_ip); /* unicast */
}
bb_error_msg("entering released state");
/*
* We can be here on: SIGUSR2,
* or on exit (SIGTERM) and -R "release on quit" is specified.
* Users requested to be notified in all cases, even if not in one
* of the states above.
*/
udhcp_run_script(NULL, "deconfig");
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change_listen_mode(LISTEN_NONE);
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state = RELEASED;
}
2006-11-28 05:13:28 +05:30
static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
{
uint8_t *storage;
int len = strnlen(str, 255);
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storage = xzalloc(len + extra + OPT_DATA);
storage[OPT_CODE] = code;
storage[OPT_LEN] = len + extra;
memcpy(storage + extra + OPT_DATA, str, len);
return storage;
}
#if BB_MMU
static void client_background(void)
{
bb_daemonize(0);
logmode &= ~LOGMODE_STDIO;
/* rewrite pidfile, as our pid is different now */
write_pidfile(client_config.pidfile);
}
#endif
//usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
//usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
//usage:#else
//usage:# define IF_UDHCP_VERBOSE(...)
//usage:#endif
//usage:#define udhcpc_trivial_usage
//usage: "[-fbq"IF_UDHCP_VERBOSE("v")"RB]"IF_FEATURE_UDHCPC_ARPING(" [-a[MSEC]]")" [-t N] [-T SEC] [-A SEC/-n]\n"
//usage: " [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-s PROG] [-p PIDFILE]\n"
//usage: " [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]..."
//usage:#define udhcpc_full_usage "\n"
//usage: "\n -i IFACE Interface to use (default eth0)"
//usage: IF_FEATURE_UDHCP_PORT(
//usage: "\n -P PORT Use PORT (default 68)"
//usage: )
//usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
//usage: "\n -p FILE Create pidfile"
//usage: "\n -B Request broadcast replies"
//usage: "\n -t N Send up to N discover packets (default 3)"
//usage: "\n -T SEC Pause between packets (default 3)"
//usage: "\n -A SEC Wait if lease is not obtained (default 20)"
//usage: "\n -n Exit if lease is not obtained"
//usage: "\n -q Exit after obtaining lease"
//usage: "\n -R Release IP on exit"
//usage: "\n -f Run in foreground"
//usage: USE_FOR_MMU(
//usage: "\n -b Background if lease is not obtained"
//usage: )
//usage: "\n -S Log to syslog too"
//usage: IF_FEATURE_UDHCPC_ARPING(
//usage: "\n -a[MSEC] Validate offered address with ARP ping"
//usage: )
//usage: "\n -r IP Request this IP address"
//usage: "\n -o Don't request any options (unless -O is given)"
//usage: "\n -O OPT Request option OPT from server (cumulative)"
//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
//usage: "\n Examples of string, numeric, and hex byte opts:"
//usage: "\n -x hostname:bbox - option 12"
//usage: "\n -x lease:3600 - option 51 (lease time)"
//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
//usage: "\n -x 14:'\"dumpfile\"' - option 14 (shell-quoted)"
//usage: "\n -F NAME Ask server to update DNS mapping for NAME"
//usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')"
//usage: "\n -C Don't send MAC as client identifier"
//usage: IF_UDHCP_VERBOSE(
//usage: "\n -v Verbose"
//usage: )
//usage: "\nSignals:"
//usage: "\n USR1 Renew lease"
//usage: "\n USR2 Release lease"
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int udhcpc_main(int argc UNUSED_PARAM, char **argv)
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{
uint8_t *message;
const char *str_V, *str_h, *str_F, *str_r;
IF_FEATURE_UDHCPC_ARPING(const char *str_a = "2000";)
IF_FEATURE_UDHCP_PORT(char *str_P;)
void *clientid_mac_ptr;
llist_t *list_O = NULL;
llist_t *list_x = NULL;
int tryagain_timeout = 20;
int discover_timeout = 3;
int discover_retries = 3;
uint32_t server_addr = server_addr; /* for compiler */
uint32_t requested_ip = 0;
uint32_t xid = xid; /* for compiler */
int packet_num;
int timeout; /* must be signed */
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unsigned already_waited_sec;
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unsigned opt;
IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;)
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int retval;
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setup_common_bufsiz();
/* Default options */
IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
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client_config.interface = "eth0";
client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
str_V = "udhcp "BB_VER;
2006-11-28 05:13:28 +05:30
/* Parse command line */
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 = getopt32long(argv, "^"
/* O,x: list; -T,-t,-A take numeric param */
"CV:H:h:F:i:np:qRr:s:T:+t:+SA:+O:*ox:*fB"
USE_FOR_MMU("b")
IF_FEATURE_UDHCPC_ARPING("a::")
IF_FEATURE_UDHCP_PORT("P:")
"v"
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
"\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */
getopt32: remove applet_long_options FEATURE_GETOPT_LONG made dependent on LONG_OPTS. The folloving options are removed, now LONG_OPTS enables long options for affected applets: FEATURE_ENV_LONG_OPTIONS FEATURE_EXPAND_LONG_OPTIONS FEATURE_UNEXPAND_LONG_OPTIONS FEATURE_MKDIR_LONG_OPTIONS FEATURE_MV_LONG_OPTIONS FEATURE_RMDIR_LONG_OPTIONS FEATURE_ADDGROUP_LONG_OPTIONS FEATURE_ADDUSER_LONG_OPTIONS FEATURE_HWCLOCK_LONG_OPTIONS FEATURE_NSENTER_LONG_OPTS FEATURE_CHCON_LONG_OPTIONS FEATURE_RUNCON_LONG_OPTIONS They either had a small number of long options, or their long options are essential. Example: upstream addgroup and adduser have ONLY longopts, we should probably go further and get rid of non-standard short options. To this end, make addgroup and adduser "select LONG_OPTS". We had this breakage caused by us even in our own package! #if ENABLE_LONG_OPTS || !ENABLE_ADDGROUP /* We try to use --gid, not -g, because "standard" addgroup * has no short option -g, it has only long --gid. */ argv[1] = (char*)"--gid"; #else /* Breaks if system in fact does NOT use busybox addgroup */ argv[1] = (char*)"-g"; #endif xargs: its lone longopt no longer depends on DESKTOP, only on LONG_OPTS. hwclock TODO: get rid of incompatible -t, -l aliases to --systz, --localtime Shorten help texts by omitting long option when short opt alternative exists. Reduction of size comes from the fact that store of an immediate (an address of longopts) to a fixed address (global variable) is a longer insn than pushing that immediate or passing it in a register. This effect is CPU-agnostic. function old new delta getopt32 1350 22 -1328 vgetopt32 - 1318 +1318 getopt32long - 24 +24 tftpd_main 562 567 +5 scan_recursive 376 380 +4 collect_cpu 545 546 +1 date_main 1096 1095 -1 hostname_main 262 259 -3 uname_main 259 255 -4 setpriv_main 362 358 -4 rmdir_main 191 187 -4 mv_main 562 558 -4 ipcalc_main 548 544 -4 ifenslave_main 641 637 -4 gzip_main 192 188 -4 gunzip_main 77 73 -4 fsfreeze_main 81 77 -4 flock_main 318 314 -4 deluser_main 337 333 -4 cp_main 374 370 -4 chown_main 175 171 -4 applet_long_options 4 - -4 xargs_main 894 889 -5 wget_main 2540 2535 -5 udhcpc_main 2767 2762 -5 touch_main 436 431 -5 tar_main 1014 1009 -5 start_stop_daemon_main 1033 1028 -5 sed_main 682 677 -5 script_main 1082 1077 -5 run_parts_main 330 325 -5 rtcwake_main 459 454 -5 od_main 2169 2164 -5 nl_main 201 196 -5 modprobe_main 773 768 -5 mkdir_main 160 155 -5 ls_main 568 563 -5 install_main 773 768 -5 hwclock_main 411 406 -5 getopt_main 622 617 -5 fstrim_main 256 251 -5 env_main 198 193 -5 dumpleases_main 635 630 -5 dpkg_main 3991 3986 -5 diff_main 1355 1350 -5 cryptpw_main 233 228 -5 cpio_main 593 588 -5 conspy_main 1135 1130 -5 chpasswd_main 313 308 -5 adduser_main 887 882 -5 addgroup_main 416 411 -5 ftpgetput_main 351 345 -6 get_terminal_width_height 242 234 -8 expand_main 690 680 -10 static.expand_longopts 18 - -18 static.unexpand_longopts 27 - -27 mkdir_longopts 28 - -28 env_longopts 30 - -30 static.ifenslave_longopts 34 - -34 mv_longopts 46 - -46 static.rmdir_longopts 48 - -48 packed_usage 31739 31687 -52 ------------------------------------------------------------------------------ (add/remove: 2/8 grow/shrink: 3/49 up/down: 1352/-1840) Total: -488 bytes text data bss dec hex filename 915681 485 6880 923046 e15a6 busybox_old 915428 485 6876 922789 e14a5 busybox_unstripped Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-08 20:08:18 +05:30
, udhcpc_longopts
, &str_V, &str_h, &str_h, &str_F
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
, &client_config.interface, &client_config.pidfile /* i,p */
, &str_r /* r */
, &client_config.script /* s */
, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
, &list_O
, &list_x
IF_FEATURE_UDHCPC_ARPING(, &str_a)
IF_FEATURE_UDHCP_PORT(, &str_P)
IF_UDHCP_VERBOSE(, &dhcp_verbose)
);
if (opt & (OPT_h|OPT_H)) {
//msg added 2011-11
bb_error_msg("option -h NAME is deprecated, use -x hostname:NAME");
2006-11-28 05:13:28 +05:30
client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
}
2006-11-28 05:13:28 +05:30
if (opt & OPT_F) {
/* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
2006-11-28 05:13:28 +05:30
client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
/* Flag bits: 0000NEOS
* S: 1 = Client requests server to update A RR in DNS as well as PTR
* O: 1 = Server indicates to client that DNS has been updated regardless
* E: 1 = Name is in DNS format, i.e. <4>host<6>domain<3>com<0>,
* not "host.domain.com". Format 0 is obsolete.
* N: 1 = Client requests server to not update DNS (S must be 0 then)
* Two [0] bytes which follow are deprecated and must be 0.
*/
2006-11-28 05:13:28 +05:30
client_config.fqdn[OPT_DATA + 0] = 0x1;
/*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
/*client_config.fqdn[OPT_DATA + 2] = 0; */
2006-11-28 05:13:28 +05:30
}
if (opt & OPT_r)
requested_ip = inet_addr(str_r);
#if ENABLE_FEATURE_UDHCP_PORT
if (opt & OPT_P) {
CLIENT_PORT = xatou16(str_P);
SERVER_PORT = CLIENT_PORT - 1;
}
#endif
IF_FEATURE_UDHCPC_ARPING(arpping_ms = xatou(str_a);)
while (list_O) {
char *optstr = llist_pop(&list_O);
unsigned n = bb_strtou(optstr, NULL, 0);
if (errno || n > 254) {
n = udhcp_option_idx(optstr, dhcp_option_strings);
n = dhcp_optflags[n].code;
}
client_config.opt_mask[n >> 3] |= 1 << (n & 7);
}
if (!(opt & OPT_o)) {
unsigned i, n;
for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
if (dhcp_optflags[i].flags & OPTION_REQ) {
client_config.opt_mask[n >> 3] |= 1 << (n & 7);
}
}
}
while (list_x) {
char *optstr = xstrdup(llist_pop(&list_x));
udhcp_str2optset(optstr, &client_config.options,
dhcp_optflags, dhcp_option_strings,
/*dhcpv6:*/ 0
);
free(optstr);
}
2006-05-08 08:50:50 +05:30
if (udhcp_read_interface(client_config.interface,
&client_config.ifindex,
NULL,
client_config.client_mac)
) {
2006-05-08 08:50:50 +05:30
return 1;
}
clientid_mac_ptr = NULL;
if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) {
/* not suppressed and not set, set the default client ID */
client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
memcpy(clientid_mac_ptr, client_config.client_mac, 6);
}
if (str_V[0] != '\0') {
// can drop -V, str_V, client_config.vendorclass,
// but need to add "vendor" to the list of recognized
// string opts for this to work;
// and need to tweak add_client_options() too...
// ...so the question is, should we?
//bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR");
client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
}
#if !BB_MMU
/* on NOMMU reexec (i.e., background) early */
if (!(opt & OPT_f)) {
bb_daemonize_or_rexec(0 /* flags */, argv);
logmode = LOGMODE_NONE;
}
#endif
if (opt & OPT_S) {
openlog(applet_name, LOG_PID, LOG_DAEMON);
logmode |= LOGMODE_SYSLOG;
}
2006-05-08 08:50:50 +05:30
/* Make sure fd 0,1,2 are open */
bb_sanitize_stdio();
/* Create pidfile */
write_pidfile(client_config.pidfile);
/* Goes to stdout (unless NOMMU) and possibly syslog */
bb_error_msg("started, v"BB_VER);
/* Set up the signal pipe */
2006-05-08 08:50:50 +05:30
udhcp_sp_setup();
/* We want random_xid to be random... */
srand(monotonic_us());
2006-05-08 08:50:50 +05:30
state = INIT_SELECTING;
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
packet_num = 0;
timeout = 0;
2008-05-21 12:33:03 +05:30
already_waited_sec = 0;
2006-05-08 08:50:50 +05:30
/* Main event loop. select() waits on signal pipe and possibly
* on sockfd.
* "continue" statements in code below jump to the top of the loop.
*/
2006-05-08 08:50:50 +05:30
for (;;) {
int tv;
struct pollfd pfds[2];
struct dhcp_packet packet;
/* silence "uninitialized!" warning */
unsigned timestamp_before_wait = timestamp_before_wait;
2006-05-08 08:50:50 +05:30
//bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
/* Was opening raw or udp socket here
* if (listen_mode != LISTEN_NONE && sockfd < 0),
* but on fast network renew responses return faster
* than we open sockets. Thus this code is moved
* to change_listen_mode(). Thus we open listen socket
* BEFORE we send renew request (see "case BOUND:"). */
udhcp_sp_fd_set(pfds, sockfd);
2006-05-08 08:50:50 +05:30
tv = timeout - already_waited_sec;
retval = 0;
/* If we already timed out, fall through with retval = 0, else... */
if (tv > 0) {
log1("waiting %u seconds", tv);
timestamp_before_wait = (unsigned)monotonic_sec();
retval = poll(pfds, 2, tv < INT_MAX/1000 ? tv * 1000 : INT_MAX);
if (retval < 0) {
/* EINTR? A signal was caught, don't panic */
if (errno == EINTR) {
already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
continue;
}
/* Else: an error occurred, panic! */
bb_perror_msg_and_die("poll");
}
}
/* If timeout dropped to zero, time to become active:
* resend discover/renew/whatever
*/
if (retval == 0) {
/* When running on a bridge, the ifindex may have changed
* (e.g. if member interfaces were added/removed
* or if the status of the bridge changed).
* Refresh ifindex and client_mac:
*/
if (udhcp_read_interface(client_config.interface,
&client_config.ifindex,
NULL,
client_config.client_mac)
) {
goto ret0; /* iface is gone? */
}
if (clientid_mac_ptr)
memcpy(clientid_mac_ptr, client_config.client_mac, 6);
/* We will restart the wait in any case */
2008-05-21 12:33:03 +05:30
already_waited_sec = 0;
2006-05-08 08:50:50 +05:30
switch (state) {
case INIT_SELECTING:
if (!discover_retries || packet_num < discover_retries) {
2006-05-08 08:50:50 +05:30
if (packet_num == 0)
xid = random_xid();
/* broadcast */
send_discover(xid, requested_ip);
timeout = discover_timeout;
2006-05-08 08:50:50 +05:30
packet_num++;
continue;
2006-05-08 08:50:50 +05:30
}
leasefail:
udhcp_run_script(NULL, "leasefail");
#if BB_MMU /* -b is not supported on NOMMU */
if (opt & OPT_b) { /* background if no lease */
bb_error_msg("no lease, forking to background");
client_background();
/* do not background again! */
opt = ((opt & ~OPT_b) | OPT_f);
} else
#endif
if (opt & OPT_n) { /* abort if no lease */
bb_error_msg("no lease, failing");
retval = 1;
goto ret;
}
/* wait before trying again */
timeout = tryagain_timeout;
packet_num = 0;
continue;
2006-05-08 08:50:50 +05:30
case REQUESTING:
if (packet_num < 3) {
/* send broadcast select packet */
send_select(xid, server_addr, requested_ip);
timeout = discover_timeout;
2006-05-08 08:50:50 +05:30
packet_num++;
continue;
2006-05-08 08:50:50 +05:30
}
/* Timed out, go back to init state.
* "discover...select...discover..." loops
2008-09-27 03:51:03 +05:30
* were seen in the wild. Treat them similarly
* to "no response to discover" case */
change_listen_mode(LISTEN_RAW);
2008-09-27 03:51:03 +05:30
state = INIT_SELECTING;
goto leasefail;
2006-05-08 08:50:50 +05:30
case BOUND:
/* 1/2 lease passed, enter renewing state */
state = RENEWING;
client_config.first_secs = 0; /* make secs field count from 0 */
change_listen_mode(LISTEN_KERNEL);
log1("entering renew state");
2006-05-08 08:50:50 +05:30
/* fall right through */
case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
case_RENEW_REQUESTED:
2006-05-08 08:50:50 +05:30
case RENEWING:
if (timeout >= 60) {
/* send an unicast renew request */
/* Sometimes observed to fail (EADDRNOTAVAIL) to bind
* a new UDP socket for sending inside send_renew.
* I hazard to guess existing listening socket
* is somehow conflicting with it, but why is it
* not deterministic then?! Strange.
* Anyway, it does recover by eventually failing through
* into INIT_SELECTING state.
*/
if (send_renew(xid, server_addr, requested_ip) >= 0) {
timeout >>= 1;
//TODO: the timeout to receive an answer for our renew should not be selected
//with "timeout = lease_seconds / 2; ...; timeout = timeout / 2": it is often huge.
//Waiting e.g. 4*3600 seconds for a reply does not make sense
//(if reply isn't coming, we keep an open socket for hours),
//it should be something like 10 seconds.
//Also, it's probably best to try sending renew in kernel mode a few (3-5) times
//and fall back to raw mode if it does not work.
continue;
}
/* else: error sending.
* example: ENETUNREACH seen with server
* which gave us bogus server ID 1.1.1.1
* which wasn't reachable (and probably did not exist).
*/
2006-05-08 08:50:50 +05:30
}
/* Timed out or error, enter rebinding state */
log1("entering rebinding state");
state = REBINDING;
/* fall right through */
2006-05-08 08:50:50 +05:30
case REBINDING:
/* Switch to bcast receive */
change_listen_mode(LISTEN_RAW);
/* Lease is *really* about to run out,
* try to find DHCP server using broadcast */
2008-05-21 12:33:03 +05:30
if (timeout > 0) {
/* send a broadcast renew request */
send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
2008-05-21 12:33:03 +05:30
timeout >>= 1;
continue;
2006-05-08 08:50:50 +05:30
}
/* Timed out, enter init state */
bb_error_msg("lease lost, entering init state");
udhcp_run_script(NULL, "deconfig");
state = INIT_SELECTING;
client_config.first_secs = 0; /* make secs field count from 0 */
2008-05-21 12:33:03 +05:30
/*timeout = 0; - already is */
packet_num = 0;
continue;
/* case RELEASED: */
2006-05-08 08:50:50 +05:30
}
/* yah, I know, *you* say it would never happen */
timeout = INT_MAX;
continue; /* back to main loop */
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 poll timed out */
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
/* poll() didn't timeout, something happened */
/* Is it a signal? */
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
switch (udhcp_sp_read()) {
case SIGUSR1:
client_config.first_secs = 0; /* make secs field count from 0 */
already_waited_sec = 0;
perform_renew();
if (state == RENEW_REQUESTED) {
/* We might be either on the same network
* (in which case renew might work),
* or we might be on a completely different one
* (in which case renew won't ever succeed).
* For the second case, must make sure timeout
* is not too big, or else we can send
* futile renew requests for hours.
*/
if (timeout > 60)
timeout = 60;
goto case_RENEW_REQUESTED;
}
/* Start things over */
packet_num = 0;
/* Kill any timeouts, user wants this to hurry along */
timeout = 0;
continue;
case SIGUSR2:
perform_release(server_addr, requested_ip);
timeout = INT_MAX;
continue;
case SIGTERM:
bb_error_msg("received %s", "SIGTERM");
goto ret0;
}
/* Is it a packet? */
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[1].revents)
continue; /* no */
{
int len;
2006-05-08 08:50:50 +05:30
/* A packet is ready, read it */
2006-05-08 08:50:50 +05:30
if (listen_mode == LISTEN_KERNEL)
len = udhcp_recv_kernel_packet(&packet, sockfd);
else
len = udhcp_recv_raw_packet(&packet, sockfd);
if (len == -1) {
/* Error is severe, reopen socket */
bb_error_msg("read error: "STRERROR_FMT", reopening socket" STRERROR_ERRNO);
sleep(discover_timeout); /* 3 seconds by default */
change_listen_mode(listen_mode); /* just close and reopen */
2006-05-08 08:50:50 +05:30
}
/* If this packet will turn out to be unrelated/bogus,
* we will go back and wait for next one.
* Be sure timeout is properly decreased. */
already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
if (len < 0)
continue;
}
2006-05-08 08:50:50 +05:30
if (packet.xid != xid) {
log1("xid %x (our is %x), ignoring packet",
(unsigned)packet.xid, (unsigned)xid);
continue;
}
2006-05-08 08:50:50 +05:30
/* Ignore packets that aren't for us */
if (packet.hlen != 6
|| memcmp(packet.chaddr, client_config.client_mac, 6) != 0
) {
//FIXME: need to also check that last 10 bytes are zero
log1("chaddr does not match, ignoring packet"); // log2?
continue;
}
2006-05-08 08:50:50 +05:30
message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
if (message == NULL) {
bb_error_msg("no message type option, ignoring packet");
continue;
}
2006-05-08 08:50:50 +05:30
switch (state) {
case INIT_SELECTING:
/* Must be a DHCPOFFER */
if (*message == DHCPOFFER) {
uint8_t *temp;
/* What exactly is server's IP? There are several values.
* Example DHCP offer captured with tchdump:
*
* 10.34.25.254:67 > 10.34.25.202:68 // IP header's src
* BOOTP fields:
* Your-IP 10.34.25.202
* Server-IP 10.34.32.125 // "next server" IP
* Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use)
* DHCP options:
* DHCP-Message Option 53, length 1: Offer
* Server-ID Option 54, length 4: 10.34.255.7 // "server ID"
* Default-Gateway Option 3, length 4: 10.34.25.254 // router
*
* We think that real server IP (one to use in renew/release)
* is one in Server-ID option. But I am not 100% sure.
* IP header's src and Gateway-IP (same in this example)
* might work too.
* "Next server" and router are definitely wrong ones to use, though...
*/
/* We used to ignore pcakets without DHCP_SERVER_ID.
* I've got user reports from people who run "address-less" servers.
* They either supply DHCP_SERVER_ID of 0.0.0.0 or don't supply it at all.
* They say ISC DHCP client supports this case.
*/
server_addr = 0;
temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
if (!temp) {
bb_error_msg("no server ID, using 0.0.0.0");
} else {
/* it IS unaligned sometimes, don't "optimize" */
move_from_unaligned32(server_addr, temp);
}
/*xid = packet.xid; - already is */
requested_ip = packet.yiaddr;
/* enter requesting state */
state = REQUESTING;
timeout = 0;
packet_num = 0;
already_waited_sec = 0;
}
continue;
case REQUESTING:
case RENEWING:
case RENEW_REQUESTED:
case REBINDING:
if (*message == DHCPACK) {
unsigned start;
uint32_t lease_seconds;
struct in_addr temp_addr;
uint8_t *temp;
temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
if (!temp) {
bb_error_msg("no lease time with ACK, using 1 hour lease");
lease_seconds = 60 * 60;
} else {
/* it IS unaligned sometimes, don't "optimize" */
move_from_unaligned32(lease_seconds, temp);
lease_seconds = ntohl(lease_seconds);
/* paranoia: must not be too small and not prone to overflows */
/* timeout > 60 - ensures at least one unicast renew attempt */
if (lease_seconds < 2 * 61)
lease_seconds = 2 * 61;
//if (lease_seconds > 0x7fffffff)
// lease_seconds = 0x7fffffff;
//^^^not necessary since "timeout = lease_seconds / 2"
//does not overflow even for 0xffffffff.
2006-05-08 08:50:50 +05:30
}
#if ENABLE_FEATURE_UDHCPC_ARPING
if (opt & OPT_a) {
/* RFC 2131 3.1 paragraph 5:
* "The client receives the DHCPACK message with configuration
* parameters. The client SHOULD perform a final check on the
* parameters (e.g., ARP for allocated network address), and notes
* the duration of the lease specified in the DHCPACK message. At this
* point, the client is configured. If the client detects that the
* address is already in use (e.g., through the use of ARP),
* the client MUST send a DHCPDECLINE message to the server and restarts
* the configuration process..." */
if (!arpping(packet.yiaddr,
NULL,
(uint32_t) 0,
client_config.client_mac,
client_config.interface,
arpping_ms)
) {
bb_error_msg("offered address is in use "
"(got ARP reply), declining");
send_decline(/*xid,*/ server_addr, packet.yiaddr);
if (state != REQUESTING)
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
state = INIT_SELECTING;
client_config.first_secs = 0; /* make secs field count from 0 */
requested_ip = 0;
timeout = tryagain_timeout;
packet_num = 0;
already_waited_sec = 0;
continue; /* back to main loop */
}
}
#endif
/* enter bound state */
temp_addr.s_addr = packet.yiaddr;
bb_error_msg("lease of %s obtained, lease time %u",
inet_ntoa(temp_addr), (unsigned)lease_seconds);
requested_ip = packet.yiaddr;
start = monotonic_sec();
udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
already_waited_sec = (unsigned)monotonic_sec() - start;
timeout = lease_seconds / 2;
if ((unsigned)timeout < already_waited_sec) {
/* Something went wrong. Back to discover state */
timeout = already_waited_sec = 0;
}
state = BOUND;
change_listen_mode(LISTEN_NONE);
if (opt & OPT_q) { /* quit after lease */
goto ret0;
2006-05-08 08:50:50 +05:30
}
/* future renew failures should not exit (JM) */
opt &= ~OPT_n;
#if BB_MMU /* NOMMU case backgrounded earlier */
if (!(opt & OPT_f)) {
client_background();
/* do not background again! */
opt = ((opt & ~OPT_b) | OPT_f);
}
#endif
/* make future renew packets use different xid */
/* xid = random_xid(); ...but why bother? */
continue; /* back to main loop */
2006-05-08 08:50:50 +05:30
}
if (*message == DHCPNAK) {
/* If network has more than one DHCP server,
* "wrong" server can reply first, with a NAK.
* Do not interpret it as a NAK from "our" server.
*/
if (server_addr != 0) {
uint32_t svid;
uint8_t *temp;
temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
if (!temp) {
non_matching_svid:
log1("received DHCP NAK with wrong"
" server ID, ignoring packet");
continue;
}
move_from_unaligned32(svid, temp);
if (svid != server_addr)
goto non_matching_svid;
}
/* return to init state */
bb_error_msg("received %s", "DHCP NAK");
udhcp_run_script(&packet, "nak");
if (state != REQUESTING)
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
sleep(3); /* avoid excessive network traffic */
state = INIT_SELECTING;
client_config.first_secs = 0; /* make secs field count from 0 */
requested_ip = 0;
timeout = 0;
packet_num = 0;
already_waited_sec = 0;
2006-05-08 08:50:50 +05:30
}
continue;
/* case BOUND: - ignore all packets */
/* case RELEASED: - ignore all packets */
2006-05-08 08:50:50 +05:30
}
/* back to main loop */
} /* for (;;) - main loop ends */
ret0:
if (opt & OPT_R) /* release on quit */
perform_release(server_addr, requested_ip);
retval = 0;
ret:
/*if (client_config.pidfile) - remove_pidfile has its own check */
remove_pidfile(client_config.pidfile);
return retval;
2006-05-08 08:50:50 +05:30
}