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traceroute: fix traceroute6 -I (icmp mode)

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function                                             old     new   delta
common_traceroute_main                              3530    3544     +14

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2020-12-12 16:38:43 +01:00
parent ef2366cdca
commit 3978adc445
1 changed files with 136 additions and 72 deletions
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208
networking/traceroute.c
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@ -414,9 +414,32 @@ struct globals {
waittime = 5; \ waittime = 5; \
} while (0) } while (0)
#define outicmp ((struct icmp *)(outip + 1)) #define outudp ((struct udphdr *)(outip + 1))
#define outudp ((struct udphdr *)(outip + 1)) #define outudp6 ((struct udphdr *)(((struct ip6_hdr*)outip) + 1))
#define outicmp ((struct icmp *)(outip + 1))
#define outicmp6 ((struct icmp *)(((struct ip6_hdr*)outip) + 1))
/* NB: for icmp echo, IPv4 and IPv6 fields are the same size and offset:
* struct icmp:
* uint8_t icmp_type;
* uint8_t icmp_code;
* uint16_t icmp_cksum;
* uint16_t icmp_id;
* uint16_t icmp_seq;
* struct icmp6_hdr:
* uint8_t icmp6_type;
* uint8_t icmp6_code;
* uint16_t icmp6_cksum;
* uint16_t icmp6_id;
* uint16_t icmp6_seq;
* therefore both outicmp and outicmp6 are pointers to *IPv4* icmp struct.
* SIZEOF_ICMP_HDR == 8 is the same for both, as well.
* However, values of these pointers are not the same (since IPv6 IP header is larger),
* and icmp_type constants are not the same:
* #define ICMP_ECHO 8
* #define ICMP_ECHOREPLY 0
* #define ICMP6_ECHO_REQUEST 128
* #define ICMP6_ECHO_REPLY 129
*/
static int static int
wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms) wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
@ -446,14 +469,16 @@ send_probe(int seq, int ttl)
{ {
int len, res; int len, res;
void *out; void *out;
struct icmp *icp;
/* Payload */ /* Payload */
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
if (dest_lsa->u.sa.sa_family == AF_INET6) { if (dest_lsa->u.sa.sa_family == AF_INET6) {
struct outdata6_t *pkt = (struct outdata6_t *) outdata; struct outdata6_t *pkt = (void *) outdata;
pkt->ident6 = htonl(ident); pkt->ident6 = htonl(ident);
pkt->seq6 = htonl(seq); pkt->seq6 = htonl(seq);
/*gettimeofday(&pkt->tv, &tz);*/ /*gettimeofday(&pkt->tv, &tz);*/
icp = outicmp6;
} else } else
#endif #endif
{ {
@ -461,19 +486,23 @@ send_probe(int seq, int ttl)
outdata->ttl = ttl; outdata->ttl = ttl;
// UNUSED: was storing gettimeofday's result there, but never ever checked it // UNUSED: was storing gettimeofday's result there, but never ever checked it
/*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/ /*memcpy(&outdata->tv, tp, sizeof(outdata->tv));*/
icp = outicmp;
if (option_mask32 & OPT_USE_ICMP) { }
outicmp->icmp_seq = htons(seq); out = outdata;
if (option_mask32 & OPT_USE_ICMP) {
/* Always calculate checksum for icmp packets */ out = icp;
outicmp->icmp_cksum = 0; /*icp->icmp_type = ICMP[6]_ECHO; - already set */
outicmp->icmp_cksum = inet_cksum( /*icp->icmp_code = 0; - already set */
outicmp, /*icp->icmp_id = ident; - already set */
((char*)outip + packlen) - (char*)outicmp icp->icmp_seq = htons(seq);
); /* Always calculate checksum for icmp packets */
if (outicmp->icmp_cksum == 0) icp->icmp_cksum = 0;
outicmp->icmp_cksum = 0xffff; icp->icmp_cksum = inet_cksum(
} icp,
((char*)outip + packlen) - (char*)icp
);
if (icp->icmp_cksum == 0)
icp->icmp_cksum = 0xffff;
} }
//BUG! verbose is (x & OPT_VERBOSE), not a counter! //BUG! verbose is (x & OPT_VERBOSE), not a counter!
@ -502,7 +531,6 @@ send_probe(int seq, int ttl)
} }
#endif #endif
out = outdata;
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
if (dest_lsa->u.sa.sa_family == AF_INET6) { if (dest_lsa->u.sa.sa_family == AF_INET6) {
res = setsockopt_int(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, ttl); res = setsockopt_int(sndsock, SOL_IPV6, IPV6_UNICAST_HOPS, ttl);
@ -516,8 +544,6 @@ send_probe(int seq, int ttl)
if (res != 0) if (res != 0)
bb_perror_msg_and_die("setsockopt(%s) %d", "TTL", ttl); bb_perror_msg_and_die("setsockopt(%s) %d", "TTL", ttl);
#endif #endif
if (option_mask32 & OPT_USE_ICMP)
out = outicmp;
} }
if (!(option_mask32 & OPT_USE_ICMP)) { if (!(option_mask32 & OPT_USE_ICMP)) {
@ -579,7 +605,12 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
int hlen; int hlen;
const struct ip *ip; const struct ip *ip;
/* NB: reads from (AF_INET, SOCK_RAW, IPPROTO_ICMP) socket
* return the entire IP packet (IOW: they do not strip IP header).
* This differs from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) sockets!?
*/
ip = (struct ip *) recv_pkt; ip = (struct ip *) recv_pkt;
hlen = ip->ip_hl << 2; hlen = ip->ip_hl << 2;
if (read_len < hlen + ICMP_MINLEN) { if (read_len < hlen + ICMP_MINLEN) {
#if ENABLE_FEATURE_TRACEROUTE_VERBOSE #if ENABLE_FEATURE_TRACEROUTE_VERBOSE
@ -598,9 +629,20 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
if (code == ICMP_UNREACH_NEEDFRAG) if (code == ICMP_UNREACH_NEEDFRAG)
pmtu = ntohs(icp->icmp_nextmtu); pmtu = ntohs(icp->icmp_nextmtu);
if ((option_mask32 & OPT_USE_ICMP)
&& type == ICMP_ECHOREPLY
&& icp->icmp_id == htons(ident)
&& icp->icmp_seq == htons(seq)
) {
/* In UDP mode, when we reach the machine, we (usually)
* would get "port unreachable" - in ICMP we got "echo reply".
* Simulate "port unreachable" for caller:
*/
return ICMP_UNREACH_PORT+1;
}
if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS) if ((type == ICMP_TIMXCEED && code == ICMP_TIMXCEED_INTRANS)
|| type == ICMP_UNREACH || type == ICMP_UNREACH
|| type == ICMP_ECHOREPLY
) { ) {
const struct ip *hip; const struct ip *hip;
const struct udphdr *up; const struct udphdr *up;
@ -610,14 +652,6 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
if (option_mask32 & OPT_USE_ICMP) { if (option_mask32 & OPT_USE_ICMP) {
struct icmp *hicmp; struct icmp *hicmp;
/* XXX */
if (type == ICMP_ECHOREPLY
&& icp->icmp_id == htons(ident)
&& icp->icmp_seq == htons(seq)
) {
return ICMP_UNREACH_PORT+1;
}
hicmp = (struct icmp *)((unsigned char *)hip + hlen); hicmp = (struct icmp *)((unsigned char *)hip + hlen);
if (hlen + SIZEOF_ICMP_HDR <= read_len if (hlen + SIZEOF_ICMP_HDR <= read_len
&& hip->ip_p == IPPROTO_ICMP && hip->ip_p == IPPROTO_ICMP
@ -648,6 +682,7 @@ packet4_ok(int read_len, const struct sockaddr_in *from, int seq)
printf("\n%d bytes from %s to " printf("\n%d bytes from %s to "
"%s: icmp type %d (%s) code %d\n", "%s: icmp type %d (%s) code %d\n",
read_len, inet_ntoa(from->sin_addr), read_len, inet_ntoa(from->sin_addr),
//BUG: inet_ntoa() returns static buf! x2 is NONO!
inet_ntoa(ip->ip_dst), inet_ntoa(ip->ip_dst),
type, pr_type(type), icp->icmp_code); type, pr_type(type), icp->icmp_code);
for (i = 4; i < read_len; i += sizeof(*lp)) for (i = 4; i < read_len; i += sizeof(*lp))
@ -673,11 +708,27 @@ packet_ok(int read_len, len_and_sockaddr *from_lsa,
if (from_lsa->u.sa.sa_family == AF_INET) if (from_lsa->u.sa.sa_family == AF_INET)
return packet4_ok(read_len, &from_lsa->u.sin, seq); return packet4_ok(read_len, &from_lsa->u.sin, seq);
/* NB: reads from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) socket
* return only ICMP packet (IOW: they strip IPv6 header).
* This differs from (AF_INET, SOCK_RAW, IPPROTO_ICMP) sockets!?
*/
icp = (struct icmp6_hdr *) recv_pkt; icp = (struct icmp6_hdr *) recv_pkt;
type = icp->icmp6_type; type = icp->icmp6_type;
code = icp->icmp6_code; code = icp->icmp6_code;
if ((option_mask32 & OPT_USE_ICMP)
&& type == ICMP6_ECHO_REPLY
&& icp->icmp6_id == htons(ident)
&& icp->icmp6_seq == htons(seq)
) {
/* In UDP mode, when we reach the machine, we (usually)
* would get "port unreachable" - in ICMP we got "echo reply".
* Simulate "port unreachable" for caller:
*/
return (ICMP6_DST_UNREACH_NOPORT << 8) + 1;
}
if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) if ((type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT)
|| type == ICMP6_DST_UNREACH || type == ICMP6_DST_UNREACH
) { ) {
@ -787,8 +838,13 @@ print(int read_len, const struct sockaddr *from, const struct sockaddr *to)
if (verbose) { if (verbose) {
char *ina = xmalloc_sockaddr2dotted_noport(to); char *ina = xmalloc_sockaddr2dotted_noport(to);
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
/* NB: reads from (AF_INET, SOCK_RAW, IPPROTO_ICMP) socket
* return the entire IP packet (IOW: they do not strip IP header).
* Reads from (AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) do strip IPv6
* header and return only ICMP6 packet. Weird.
*/
if (to->sa_family == AF_INET6) { if (to->sa_family == AF_INET6) {
read_len -= sizeof(struct ip6_hdr); /* read_len -= sizeof(struct ip6_hdr); - WRONG! */
} else } else
#endif #endif
{ {
@ -844,6 +900,9 @@ common_traceroute_main(int op, char **argv)
struct sockaddr *lastaddr; struct sockaddr *lastaddr;
struct sockaddr *to; struct sockaddr *to;
/* Ensure the socket fds won't be 0, 1 or 2 */
bb_sanitize_stdio();
INIT_G(); INIT_G();
op |= getopt32(argv, "^" op |= getopt32(argv, "^"
@ -885,12 +944,14 @@ common_traceroute_main(int op, char **argv)
/* Process destination and optional packet size */ /* Process destination and optional packet size */
minpacket = sizeof(struct ip) minpacket = sizeof(struct ip)
+ SIZEOF_ICMP_HDR
+ sizeof(struct outdata_t);
if (!(op & OPT_USE_ICMP))
minpacket = sizeof(struct ip)
+ sizeof(struct udphdr) + sizeof(struct udphdr)
+ sizeof(struct outdata_t); + sizeof(struct outdata_t);
if (op & OPT_USE_ICMP) {
minpacket = sizeof(struct ip)
+ SIZEOF_ICMP_HDR
+ sizeof(struct outdata_t);
port = 0; /* on ICMP6 sockets, sendto(ipv6.nonzero_port) throws EINVAL */
}
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
af = AF_UNSPEC; af = AF_UNSPEC;
if (op & OPT_IPV4) if (op & OPT_IPV4)
@ -899,10 +960,15 @@ common_traceroute_main(int op, char **argv)
af = AF_INET6; af = AF_INET6;
dest_lsa = xhost_and_af2sockaddr(argv[0], port, af); dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
af = dest_lsa->u.sa.sa_family; af = dest_lsa->u.sa.sa_family;
if (af == AF_INET6) if (af == AF_INET6) {
minpacket = sizeof(struct ip6_hdr) minpacket = sizeof(struct ip6_hdr)
+ sizeof(struct udphdr) + sizeof(struct udphdr)
+ sizeof(struct outdata6_t); + sizeof(struct outdata6_t);
if (op & OPT_USE_ICMP)
minpacket = sizeof(struct ip6_hdr)
+ SIZEOF_ICMP_HDR
+ sizeof(struct outdata6_t);
}
#else #else
dest_lsa = xhost2sockaddr(argv[0], port); dest_lsa = xhost2sockaddr(argv[0], port);
#endif #endif
@ -910,13 +976,10 @@ common_traceroute_main(int op, char **argv)
if (argv[1]) if (argv[1])
packlen = xatoul_range(argv[1], minpacket, 32 * 1024); packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
/* Ensure the socket fds won't be 0, 1 or 2 */
bb_sanitize_stdio();
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
if (af == AF_INET6) { if (af == AF_INET6) {
xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock); xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO); setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO); //why?
} else } else
#endif #endif
{ {
@ -934,7 +997,10 @@ common_traceroute_main(int op, char **argv)
if (af == AF_INET6) { if (af == AF_INET6) {
if (setsockopt_int(rcvsock, SOL_RAW, IPV6_CHECKSUM, 2) != 0) if (setsockopt_int(rcvsock, SOL_RAW, IPV6_CHECKSUM, 2) != 0)
bb_perror_msg_and_die("setsockopt(%s)", "IPV6_CHECKSUM"); bb_perror_msg_and_die("setsockopt(%s)", "IPV6_CHECKSUM");
xmove_fd(xsocket(af, SOCK_DGRAM, 0), sndsock); if (op & OPT_USE_ICMP)
xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), sndsock);
else
xmove_fd(xsocket(AF_INET6, SOCK_DGRAM, 0), sndsock);
} else } else
#endif #endif
{ {
@ -943,6 +1009,7 @@ common_traceroute_main(int op, char **argv)
else else
xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock); xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sndsock);
} }
//TODO xmove_fd to here!
#ifdef SO_SNDBUF #ifdef SO_SNDBUF
if (setsockopt_SOL_SOCKET_int(sndsock, SO_SNDBUF, packlen) != 0) { if (setsockopt_SOL_SOCKET_int(sndsock, SO_SNDBUF, packlen) != 0) {
@ -970,21 +1037,25 @@ common_traceroute_main(int op, char **argv)
ident = getpid(); ident = getpid();
if (!ENABLE_TRACEROUTE6 || af == AF_INET) { if (!ENABLE_TRACEROUTE6 || af == AF_INET) {
outdata = (void*)(outudp + 1);
if (op & OPT_USE_ICMP) { if (op & OPT_USE_ICMP) {
ident |= 0x8000; ident |= 0x8000;
outicmp->icmp_type = ICMP_ECHO; outicmp->icmp_type = ICMP_ECHO;
/*outicmp->icmp_code = 0; - set by xzalloc */
outicmp->icmp_id = htons(ident); outicmp->icmp_id = htons(ident);
outdata = (struct outdata_t *)((char *)outicmp + SIZEOF_ICMP_HDR); outdata = (void*)((char *)outicmp + SIZEOF_ICMP_HDR);
} else {
outdata = (struct outdata_t *)(outudp + 1);
} }
} }
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
if (af == AF_INET6) { if (af == AF_INET6) {
outdata = (void*)((char*)outip outdata = (void*)(outudp6 + 1);
+ sizeof(struct ip6_hdr) if (op & OPT_USE_ICMP) {
+ sizeof(struct udphdr) ident |= 0x8000;
); outicmp6->icmp_type = ICMP6_ECHO_REQUEST;
/*outicmp->icmp_code = 0; - set by xzalloc */
outicmp6->icmp_id = htons(ident);
outdata = (void*)((char *)outicmp6 + SIZEOF_ICMP_HDR);
}
} }
#endif #endif
@ -1013,26 +1084,16 @@ common_traceroute_main(int op, char **argv)
//TODO: why we don't do it for IPv4? //TODO: why we don't do it for IPv4?
len_and_sockaddr *source_lsa; len_and_sockaddr *source_lsa;
int probe_fd = xsocket(af, SOCK_DGRAM, 0);
if (op & OPT_DEVICE)
setsockopt_bindtodevice(probe_fd, device);
set_nport(&dest_lsa->u.sa, htons(1025));
/* dummy connect. makes kernel pick source IP (and port) */
xconnect(probe_fd, &dest_lsa->u.sa, dest_lsa->len);
set_nport(&dest_lsa->u.sa, htons(port)); set_nport(&dest_lsa->u.sa, htons(port));
/* Connect makes kernel pick source IP and port */
/* read IP and port */ xconnect(sndsock, &dest_lsa->u.sa, dest_lsa->len);
source_lsa = get_sock_lsa(probe_fd); /* Read IP and port */
source_lsa = get_sock_lsa(sndsock);
if (source_lsa == NULL) if (source_lsa == NULL)
bb_simple_error_msg_and_die("can't get probe addr"); bb_simple_error_msg_and_die("can't get probe addr");
/* bind our recv socket to this IP (but not port) */
close(probe_fd);
/* bind our sockets to this IP (but not port) */
set_nport(&source_lsa->u.sa, 0); set_nport(&source_lsa->u.sa, 0);
xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
xbind(rcvsock, &source_lsa->u.sa, source_lsa->len); xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
free(source_lsa); free(source_lsa);
} }
#endif #endif
@ -1067,10 +1128,9 @@ common_traceroute_main(int op, char **argv)
unsigned t1; unsigned t1;
unsigned t2; unsigned t2;
int left_ms; int left_ms;
struct ip *ip;
fflush_all(); fflush_all();
if (probe != 0 && pausemsecs > 0) if (probe != 0)
msleep(pausemsecs); msleep(pausemsecs);
send_probe(++seq, ttl); send_probe(++seq, ttl);
@ -1099,15 +1159,18 @@ common_traceroute_main(int op, char **argv)
} }
print_delta_ms(t1, t2); print_delta_ms(t1, t2);
ip = (struct ip *)recv_pkt;
if (from_lsa->u.sa.sa_family == AF_INET) if (from_lsa->u.sa.sa_family == AF_INET) {
if (op & OPT_TTL_FLAG) if (op & OPT_TTL_FLAG) {
struct ip *ip = (struct ip *)recv_pkt;
printf(" (%d)", ip->ip_ttl); printf(" (%d)", ip->ip_ttl);
}
}
/* time exceeded in transit */ /* Got a "time exceeded in transit" icmp message? */
if (icmp_code == -1) if (icmp_code == -1)
break; break;
icmp_code--; icmp_code--;
switch (icmp_code) { switch (icmp_code) {
#if ENABLE_TRACEROUTE6 #if ENABLE_TRACEROUTE6
@ -1115,12 +1178,13 @@ common_traceroute_main(int op, char **argv)
got_there = 1; got_there = 1;
break; break;
#endif #endif
case ICMP_UNREACH_PORT: case ICMP_UNREACH_PORT: {
struct ip *ip = (struct ip *)recv_pkt;
if (ip->ip_ttl <= 1) if (ip->ip_ttl <= 1)
printf(" !"); printf(" !");
got_there = 1; got_there = 1;
break; break;
}
case ICMP_UNREACH_NET: case ICMP_UNREACH_NET:
#if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET) #if ENABLE_TRACEROUTE6 && (ICMP6_DST_UNREACH_NOROUTE != ICMP_UNREACH_NET)
case ICMP6_DST_UNREACH_NOROUTE << 8: case ICMP6_DST_UNREACH_NOROUTE << 8: