traceroute: set IP_PKTINFO to see correct local IP of received pkt (fixes -v display)

Also, assorted code shrink:

function                                             old     new   delta
traceroute_init                                     1210    1172     -38
common_traceroute_main                              2141    2091     -50
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-88)             Total: -88 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2020-12-12 20:08:36 +01:00
parent cc55bbef75
commit df5c5394b0

View File

@ -413,7 +413,6 @@ struct globals {
#define port (G.port )
#define waittime (G.waittime )
#define recv_pkt (G.recv_pkt )
#define gwlist (G.gwlist )
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)
@ -683,12 +682,15 @@ packet4_ok(int read_len, int seq)
int i;
uint32_t *lp = (uint32_t *)&icp->icmp_ip;
printf("\n%d bytes from %s",
read_len, inet_ntoa(G.from_lsa->u.sin.sin_addr));
/* Two separate printf() because inet_ntoa() returns static string */
printf(" to %s: icmp type %d (%s) code %d\n",
printf("\n%d bytes from %s to %s: icmp type %d (%s) code %d\n",
read_len,
/* inet_ntoa(G.from_lsa->u.sin.sin_addr) - two calls of inet_ntoa()
* are unsafe (use the same buffer), using this instead:
*/
auto_string(xmalloc_sockaddr2dotted_noport(&G.from_lsa->u.sa)),
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))
printf("%2d: x%8.8x\n", i, *lp++);
}
@ -756,19 +758,16 @@ packet6_ok(int read_len, int seq)
# if ENABLE_FEATURE_TRACEROUTE_VERBOSE
if (verbose) {
unsigned char *p;
char pa[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff") + 4];
int i;
p = (unsigned char *) (icp + 1);
printf("\n%d bytes from %s",
printf("\n%d bytes from %s to %s: icmp type %d (%s) code %d\n",
read_len,
inet_ntop(AF_INET6, &G.from_lsa->u.sin6.sin6_addr, pa, sizeof(pa)));
/* Two printf() instead of one - reuse string constants */
printf(" to %s: icmp type %d (%s) code %d\n",
inet_ntop(AF_INET6, &((struct sockaddr_in6*)G.to)->sin6_addr, pa, sizeof(pa)),
type, pr_type(type), icp->icmp6_code);
auto_string(xmalloc_sockaddr2dotted_noport(&G.from_lsa->u.sa)),
auto_string(xmalloc_sockaddr2dotted_noport(G.to)),
type, pr_type(type), icp->icmp6_code
);
read_len -= sizeof(struct icmp6_hdr);
for (i = 0; i < read_len; i++) {
if (i % 16 == 0)
@ -796,55 +795,36 @@ packet_ok(int read_len, int seq)
#else /* !ENABLE_TRACEROUTE6 */
static ALWAYS_INLINE int
packet_ok(int read_len, int seq)
{
return packet4_ok(read_len, seq);
}
# define packet_ok(read_len, seq) packet4_ok(read_len, seq)
#endif
/*
* Construct an Internet address representation.
* If the -n flag has been supplied, give
* numeric value, otherwise try for symbolic name.
*/
static void
print_inetname(const struct sockaddr *from)
print(int read_len)
{
char *ina = xmalloc_sockaddr2dotted_noport(from);
char *ina = auto_string(xmalloc_sockaddr2dotted_noport(&G.from_lsa->u.sa));
if (option_mask32 & OPT_ADDR_NUM) {
printf(" %s", ina);
} else {
char *n = NULL;
if (from->sa_family != AF_INET
|| ((struct sockaddr_in*)from)->sin_addr.s_addr != INADDR_ANY
if (G.from_lsa->u.sa.sa_family != AF_INET
|| G.from_lsa->u.sin.sin_addr.s_addr != INADDR_ANY
) {
/* Try to reverse resolve if it is not 0.0.0.0 */
n = xmalloc_sockaddr2host_noport((struct sockaddr*)from);
n = auto_string(xmalloc_sockaddr2host_noport(&G.from_lsa->u.sa));
}
printf(" %s (%s)", (n ? n : ina), ina);
free(n);
}
free(ina);
}
static void
print(int read_len)
{
print_inetname(&G.from_lsa->u.sa);
if (verbose) {
char *ina = xmalloc_sockaddr2dotted_noport(G.to);
#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 (G.to->sa_family == AF_INET6) {
if (G.from_lsa->u.sa.sa_family == AF_INET6) {
/* read_len -= sizeof(struct ip6_hdr); - WRONG! */
} else
#endif
@ -852,8 +832,9 @@ print(int read_len)
struct ip *ip4packet = (struct ip*)recv_pkt;
read_len -= ip4packet->ip_hl << 2;
}
printf(" %d bytes to %s", read_len, ina);
free(ina);
printf(" %d bytes to %s", read_len,
auto_string(xmalloc_sockaddr2dotted_noport(G.to))
);
}
}
@ -870,10 +851,6 @@ print_delta_ms(unsigned t1p, unsigned t2p)
static NOINLINE void
traceroute_init(int op, char **argv)
{
int minpacket;
#ifdef IP_TOS
int tos = 0;
#endif
char *source;
char *device;
char *tos_str;
@ -911,10 +888,6 @@ traceroute_init(int op, char **argv)
#if 0 /* IGNORED */
if (op & OPT_IP_CHKSUM)
bb_error_msg("warning: ip checksums disabled");
#endif
#ifdef IP_TOS
if (op & OPT_TOS)
tos = xatou_range(tos_str, 0, 255);
#endif
if (op & OPT_MAX_TTL)
G.max_ttl = xatou_range(max_ttl_str, 1, 255);
@ -930,11 +903,11 @@ traceroute_init(int op, char **argv)
G.first_ttl = xatou_range(first_ttl_str, 1, G.max_ttl);
/* Process destination and optional packet size */
minpacket = sizeof(struct ip)
packlen = sizeof(struct ip)
+ sizeof(struct udphdr)
+ sizeof(struct outdata_t);
if (op & OPT_USE_ICMP) {
minpacket = sizeof(struct ip)
packlen = sizeof(struct ip)
+ SIZEOF_ICMP_HDR
+ sizeof(struct outdata_t);
port = 0; /* on ICMP6 sockets, sendto(ipv6.nonzero_port) throws EINVAL */
@ -948,11 +921,11 @@ traceroute_init(int op, char **argv)
dest_lsa = xhost_and_af2sockaddr(argv[0], port, af);
af = dest_lsa->u.sa.sa_family;
if (af == AF_INET6) {
minpacket = sizeof(struct ip6_hdr)
packlen = sizeof(struct ip6_hdr)
+ sizeof(struct udphdr)
+ sizeof(struct outdata6_t);
if (op & OPT_USE_ICMP)
minpacket = sizeof(struct ip6_hdr)
packlen = sizeof(struct ip6_hdr)
+ SIZEOF_ICMP_HDR
+ sizeof(struct outdata6_t);
}
@ -961,19 +934,20 @@ traceroute_init(int op, char **argv)
#endif
G.from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
G.to = xzalloc(dest_lsa->len);
packlen = minpacket;
if (argv[1])
packlen = xatoul_range(argv[1], minpacket, 32 * 1024);
packlen = xatoul_range(argv[1], packlen, 32 * 1024);
#if ENABLE_TRACEROUTE6
if (af == AF_INET6) {
xmove_fd(xsocket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6), rcvsock);
setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO); //why?
/* want recvmsg to report target local address (for -v) */
setsockopt_1(rcvsock, SOL_IPV6, IPV6_RECVPKTINFO);
} else
#endif
{
xmove_fd(xsocket(AF_INET, SOCK_RAW, IPPROTO_ICMP), rcvsock);
/* want recvmsg to report target local address (for -v) */
setsockopt_1(rcvsock, IPPROTO_IP, IP_PKTINFO);
}
#if TRACEROUTE_SO_DEBUG
@ -1010,8 +984,10 @@ traceroute_init(int op, char **argv)
}
#endif
#ifdef IP_TOS
if ((op & OPT_TOS) && setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0) {
bb_perror_msg_and_die("setsockopt(%s) %d", "TOS", tos);
if (op & OPT_TOS) {
int tos = xatou_range(tos_str, 0, 255);
if (setsockopt_int(sndsock, IPPROTO_IP, IP_TOS, tos) != 0)
bb_perror_msg_and_die("setsockopt(%s,%d)", "TOS", tos);
}
#endif
#ifdef IP_DONTFRAG
@ -1070,7 +1046,8 @@ traceroute_init(int op, char **argv)
//TODO: we can query source port we bound to,
// and check it in replies... if we care enough
xbind(sndsock, &source_lsa->u.sa, source_lsa->len);
free(source_lsa);
if (ENABLE_FEATURE_CLEAN_UP)
free(source_lsa);
}
#if ENABLE_TRACEROUTE6
else if (af == AF_INET6) {
@ -1087,7 +1064,8 @@ traceroute_init(int op, char **argv)
/* bind our recv socket to this IP (but not port) */
set_nport(&source_lsa->u.sa, 0);
xbind(rcvsock, &source_lsa->u.sa, source_lsa->len);
free(source_lsa);
if (ENABLE_FEATURE_CLEAN_UP)
free(source_lsa);
}
#endif
@ -1097,9 +1075,8 @@ traceroute_init(int op, char **argv)
dest_str = xmalloc_sockaddr2dotted_noport(&dest_lsa->u.sa);
printf("traceroute to %s (%s)", argv[0], dest_str);
if (ENABLE_FEATURE_CLEAN_UP) {
if (ENABLE_FEATURE_CLEAN_UP)
free(dest_str);
}
if (op & OPT_SOURCE)
printf(" from %s", source);