busybox/networking/udhcp/d6_packet.c

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/* vi: set sw=4 ts=4: */
/*
* Copyright (C) 2011 Denys Vlasenko.
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
#include "common.h"
#include "d6_common.h"
#include "dhcpd.h"
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netpacket/packet.h>
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
void FAST_FUNC d6_dump_packet(struct d6_packet *packet)
{
if (dhcp_verbose < 2)
return;
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(
" xid %x"
, packet->d6_xid32
);
//*bin2hex(buf, (void *) packet->chaddr, sizeof(packet->chaddr)) = '\0';
//bb_error_msg(" chaddr %s", buf);
}
#endif
int FAST_FUNC d6_recv_kernel_packet(struct in6_addr *peer_ipv6
UNUSED_PARAM
, struct d6_packet *packet, int fd)
{
int bytes;
memset(packet, 0, sizeof(*packet));
bytes = safe_read(fd, packet, sizeof(*packet));
if (bytes < 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("packet read error, ignoring");
return bytes; /* returns -1 */
}
if (bytes < offsetof(struct d6_packet, d6_options)) {
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("packet with bad magic, ignoring");
return -2;
}
log1("received %s", "a packet");
d6_dump_packet(packet);
return bytes;
}
/* Construct a ipv6+udp header for a packet, send packet */
int FAST_FUNC d6_send_raw_packet(
struct d6_packet *d6_pkt, unsigned d6_pkt_size,
struct in6_addr *src_ipv6, int source_port,
struct in6_addr *dst_ipv6, int dest_port, const uint8_t *dest_arp,
int ifindex)
{
struct sockaddr_ll dest_sll;
struct ip6_udp_d6_packet packet;
int fd;
int result = -1;
const char *msg;
fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
if (fd < 0) {
msg = "socket(%s)";
goto ret_msg;
}
memset(&dest_sll, 0, sizeof(dest_sll));
memset(&packet, 0, offsetof(struct ip6_udp_d6_packet, data));
packet.data = *d6_pkt; /* struct copy */
dest_sll.sll_family = AF_PACKET;
dest_sll.sll_protocol = htons(ETH_P_IPV6);
dest_sll.sll_ifindex = ifindex;
/*dest_sll.sll_hatype = ARPHRD_???;*/
/*dest_sll.sll_pkttype = PACKET_???;*/
dest_sll.sll_halen = 6;
memcpy(dest_sll.sll_addr, dest_arp, 6);
if (bind(fd, (struct sockaddr *)&dest_sll, sizeof(dest_sll)) < 0) {
msg = "bind(%s)";
goto ret_close;
}
packet.ip6.ip6_vfc = (6 << 4); /* 4 bits version, top 4 bits of tclass */
if (src_ipv6)
packet.ip6.ip6_src = *src_ipv6; /* struct copy */
packet.ip6.ip6_dst = *dst_ipv6; /* struct copy */
packet.udp.source = htons(source_port);
packet.udp.dest = htons(dest_port);
/* size, excluding IP header: */
packet.udp.len = htons(sizeof(struct udphdr) + d6_pkt_size);
packet.ip6.ip6_plen = packet.udp.len;
/*
* Someone was smoking weed (at least) while inventing UDP checksumming:
* UDP checksum skips first four bytes of IPv6 header.
* 'next header' field should be summed as if it is one more byte
* to the right, therefore we write its value (IPPROTO_UDP)
* into ip6_hlim, and its 'real' location remains zero-filled for now.
*/
packet.ip6.ip6_hlim = IPPROTO_UDP;
packet.udp.check = inet_cksum(
(uint8_t *)&packet + 4,
offsetof(struct ip6_udp_d6_packet, data) - 4 + d6_pkt_size
);
/* fix 'hop limit' and 'next header' after UDP checksumming */
packet.ip6.ip6_hlim = 1; /* observed Windows machines to use hlim=1 */
packet.ip6.ip6_nxt = IPPROTO_UDP;
d6_dump_packet(d6_pkt);
result = sendto(fd, &packet, offsetof(struct ip6_udp_d6_packet, data) + d6_pkt_size,
/*flags:*/ 0,
(struct sockaddr *) &dest_sll, sizeof(dest_sll)
);
msg = "sendto";
ret_close:
close(fd);
if (result < 0) {
ret_msg:
bb_perror_msg(msg, "PACKET");
}
return result;
}
/* Let the kernel do all the work for packet generation */
int FAST_FUNC d6_send_kernel_packet(
struct d6_packet *d6_pkt, unsigned d6_pkt_size,
struct in6_addr *src_ipv6, int source_port,
struct in6_addr *dst_ipv6, int dest_port,
int ifindex)
{
struct sockaddr_in6 sa;
int fd;
int result = -1;
const char *msg;
fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
if (fd < 0) {
msg = "socket(%s)";
goto ret_msg;
}
setsockopt_reuseaddr(fd);
memset(&sa, 0, sizeof(sa));
sa.sin6_family = AF_INET6;
sa.sin6_port = htons(source_port);
sa.sin6_addr = *src_ipv6; /* struct copy */
if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
msg = "bind(%s)";
goto ret_close;
}
memset(&sa, 0, sizeof(sa));
sa.sin6_family = AF_INET6;
sa.sin6_port = htons(dest_port);
sa.sin6_addr = *dst_ipv6; /* struct copy */
sa.sin6_scope_id = ifindex;
if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
msg = "connect";
goto ret_close;
}
d6_dump_packet(d6_pkt);
result = safe_write(fd, d6_pkt, d6_pkt_size);
msg = "write";
ret_close:
close(fd);
if (result < 0) {
ret_msg:
bb_perror_msg(msg, "UDP");
}
return result;
}