ping: do not leak data from stack; shrink
FANCY ping: function old new delta common_ping_main 386 1732 +1346 sendping6 98 83 -15 sendping4 188 158 -30 ping4 575 - -575 ping6 756 - -756 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 1/2 up/down: 1346/-1376) Total: -30 bytes !FANCY ping: function old new delta hostname 4 - -4 common_ping_main 566 499 -67 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
5749328b56
commit
9341fd2d30
@ -43,13 +43,12 @@ enum {
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DEFDATALEN = 56,
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MAXIPLEN = 60,
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MAXICMPLEN = 76,
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MAXPACKET = 65468,
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MAX_DUP_CHK = (8 * 128),
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MAXWAIT = 10,
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PINGINTERVAL = 1, /* 1 second */
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};
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/* common routines */
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/* Common routines */
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static int in_cksum(unsigned short *buf, int sz)
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{
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@ -76,40 +75,41 @@ static int in_cksum(unsigned short *buf, int sz)
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#if !ENABLE_FEATURE_FANCY_PING
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/* simple version */
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/* Simple version */
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static char *hostname;
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struct globals {
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char *hostname;
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char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
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} FIX_ALIASING;
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#define G (*(struct globals*)&bb_common_bufsiz1)
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#define INIT_G() do { } while (0)
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static void noresp(int ign UNUSED_PARAM)
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{
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printf("No response from %s\n", hostname);
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printf("No response from %s\n", G.hostname);
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exit(EXIT_FAILURE);
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}
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static void ping4(len_and_sockaddr *lsa)
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{
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struct sockaddr_in pingaddr;
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struct icmp *pkt;
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int pingsock, c;
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char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
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pingsock = create_icmp_socket();
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pingaddr = lsa->u.sin;
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pkt = (struct icmp *) packet;
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memset(pkt, 0, sizeof(packet));
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pkt = (struct icmp *) G.packet;
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memset(pkt, 0, sizeof(G.packet));
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pkt->icmp_type = ICMP_ECHO;
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pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
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pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(G.packet));
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c = xsendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN,
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(struct sockaddr *) &pingaddr, sizeof(pingaddr));
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xsendto(pingsock, G.packet, DEFDATALEN + ICMP_MINLEN, &lsa->u.sa, lsa->len);
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/* listen for replies */
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while (1) {
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struct sockaddr_in from;
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socklen_t fromlen = sizeof(from);
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c = recvfrom(pingsock, packet, sizeof(packet), 0,
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c = recvfrom(pingsock, G.packet, sizeof(G.packet), 0,
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(struct sockaddr *) &from, &fromlen);
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if (c < 0) {
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if (errno != EINTR)
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@ -117,9 +117,9 @@ static void ping4(len_and_sockaddr *lsa)
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continue;
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}
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if (c >= 76) { /* ip + icmp */
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struct iphdr *iphdr = (struct iphdr *) packet;
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struct iphdr *iphdr = (struct iphdr *) G.packet;
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pkt = (struct icmp *) (packet + (iphdr->ihl << 2)); /* skip ip hdr */
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pkt = (struct icmp *) (G.packet + (iphdr->ihl << 2)); /* skip ip hdr */
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if (pkt->icmp_type == ICMP_ECHOREPLY)
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break;
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}
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@ -131,31 +131,27 @@ static void ping4(len_and_sockaddr *lsa)
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#if ENABLE_PING6
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static void ping6(len_and_sockaddr *lsa)
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{
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struct sockaddr_in6 pingaddr;
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struct icmp6_hdr *pkt;
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int pingsock, c;
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int sockopt;
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char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
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pingsock = create_icmp6_socket();
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pingaddr = lsa->u.sin6;
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pkt = (struct icmp6_hdr *) packet;
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memset(pkt, 0, sizeof(packet));
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pkt = (struct icmp6_hdr *) G.packet;
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memset(pkt, 0, sizeof(G.packet));
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pkt->icmp6_type = ICMP6_ECHO_REQUEST;
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sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
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setsockopt(pingsock, SOL_RAW, IPV6_CHECKSUM, &sockopt, sizeof(sockopt));
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c = xsendto(pingsock, packet, DEFDATALEN + sizeof (struct icmp6_hdr),
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(struct sockaddr *) &pingaddr, sizeof(pingaddr));
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xsendto(pingsock, G.packet, DEFDATALEN + sizeof(struct icmp6_hdr), &lsa->u.sa, lsa->len);
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/* listen for replies */
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while (1) {
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struct sockaddr_in6 from;
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socklen_t fromlen = sizeof(from);
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c = recvfrom(pingsock, packet, sizeof(packet), 0,
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c = recvfrom(pingsock, G.packet, sizeof(G.packet), 0,
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(struct sockaddr *) &from, &fromlen);
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if (c < 0) {
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if (errno != EINTR)
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@ -163,7 +159,7 @@ static void ping6(len_and_sockaddr *lsa)
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continue;
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}
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if (c >= ICMP_MINLEN) { /* icmp6_hdr */
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pkt = (struct icmp6_hdr *) packet;
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pkt = (struct icmp6_hdr *) G.packet;
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if (pkt->icmp6_type == ICMP6_ECHO_REPLY)
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break;
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}
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@ -180,6 +176,8 @@ static int common_ping_main(sa_family_t af, char **argv)
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{
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len_and_sockaddr *lsa;
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INIT_G();
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#if ENABLE_PING6
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while ((++argv)[0] && argv[0][0] == '-') {
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if (argv[0][1] == '4') {
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@ -196,14 +194,14 @@ static int common_ping_main(sa_family_t af, char **argv)
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argv++;
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#endif
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hostname = *argv;
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if (!hostname)
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G.hostname = *argv;
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if (!G.hostname)
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bb_show_usage();
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#if ENABLE_PING6
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lsa = xhost_and_af2sockaddr(hostname, 0, af);
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lsa = xhost_and_af2sockaddr(G.hostname, 0, af);
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#else
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lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET);
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lsa = xhost_and_af2sockaddr(G.hostname, 0, AF_INET);
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#endif
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/* Set timer _after_ DNS resolution */
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signal(SIGALRM, noresp);
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@ -215,7 +213,7 @@ static int common_ping_main(sa_family_t af, char **argv)
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else
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#endif
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ping4(lsa);
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printf("%s is alive!\n", hostname);
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printf("%s is alive!\n", G.hostname);
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return EXIT_SUCCESS;
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}
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@ -223,7 +221,7 @@ static int common_ping_main(sa_family_t af, char **argv)
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#else /* FEATURE_FANCY_PING */
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/* full(er) version */
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/* Full(er) version */
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#define OPT_STRING ("qvc:s:w:W:I:4" IF_PING6("6"))
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enum {
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@ -253,6 +251,9 @@ struct globals {
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unsigned deadline;
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unsigned timeout;
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unsigned total_secs;
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unsigned sizeof_rcv_packet;
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char *rcv_packet; /* [datalen + MAXIPLEN + MAXICMPLEN] */
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void *snd_packet; /* [datalen + ipv4/ipv6_const] */
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const char *hostname;
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const char *dotted;
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union {
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@ -370,19 +371,20 @@ static void sendping_tail(void (*sp)(int), const void *pkt, int size_pkt)
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static void sendping4(int junk UNUSED_PARAM)
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{
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/* +4 reserves a place for timestamp, which may end up sitting
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* *after* packet. Saves one if() */
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struct icmp *pkt = alloca(datalen + ICMP_MINLEN + 4);
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struct icmp *pkt = G.snd_packet;
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memset(pkt, 0, datalen + ICMP_MINLEN + 4);
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//memset(pkt, 0, datalen + ICMP_MINLEN + 4); - G.snd_packet was xzalloced
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pkt->icmp_type = ICMP_ECHO;
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/*pkt->icmp_code = 0;*/
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/*pkt->icmp_cksum = 0;*/
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pkt->icmp_cksum = 0; /* cksum is calculated with this field set to 0 */
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pkt->icmp_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
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pkt->icmp_id = myid;
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/* We don't do hton, because we will read it back on the same machine */
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/* If datalen < 4, we store timestamp _past_ the packet,
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* but it's ok - we allocated 4 extra bytes in xzalloc() just in case.
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*/
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/*if (datalen >= 4)*/
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/* No hton: we'll read it back on the same machine */
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*(uint32_t*)&pkt->icmp_dun = monotonic_us();
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pkt->icmp_cksum = in_cksum((unsigned short *) pkt, datalen + ICMP_MINLEN);
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@ -394,7 +396,7 @@ static void sendping6(int junk UNUSED_PARAM)
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{
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struct icmp6_hdr *pkt = alloca(datalen + sizeof(struct icmp6_hdr) + 4);
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memset(pkt, 0, datalen + sizeof(struct icmp6_hdr) + 4);
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//memset(pkt, 0, datalen + sizeof(struct icmp6_hdr) + 4);
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pkt->icmp6_type = ICMP6_ECHO_REQUEST;
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/*pkt->icmp6_code = 0;*/
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/*pkt->icmp6_cksum = 0;*/
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@ -404,6 +406,8 @@ static void sendping6(int junk UNUSED_PARAM)
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/*if (datalen >= 4)*/
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*(uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us();
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//TODO? pkt->icmp_cksum = in_cksum(...);
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sendping_tail(sendping6, pkt, datalen + sizeof(struct icmp6_hdr));
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}
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#endif
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@ -561,7 +565,6 @@ static void unpack6(char *packet, int sz, /*struct sockaddr_in6 *from,*/ int hop
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static void ping4(len_and_sockaddr *lsa)
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{
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char packet[datalen + MAXIPLEN + MAXICMPLEN];
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int sockopt;
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pingsock = create_icmp_socket();
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@ -594,14 +597,14 @@ static void ping4(len_and_sockaddr *lsa)
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socklen_t fromlen = (socklen_t) sizeof(from);
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int c;
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c = recvfrom(pingsock, packet, sizeof(packet), 0,
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c = recvfrom(pingsock, G.rcv_packet, G.sizeof_rcv_packet, 0,
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(struct sockaddr *) &from, &fromlen);
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if (c < 0) {
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if (errno != EINTR)
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bb_perror_msg("recvfrom");
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continue;
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}
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unpack4(packet, c, &from);
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unpack4(G.rcv_packet, c, &from);
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if (pingcount && nreceived >= pingcount)
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break;
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}
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@ -610,7 +613,6 @@ static void ping4(len_and_sockaddr *lsa)
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extern int BUG_bad_offsetof_icmp6_cksum(void);
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static void ping6(len_and_sockaddr *lsa)
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{
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char packet[datalen + MAXIPLEN + MAXICMPLEN];
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int sockopt;
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struct msghdr msg;
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struct sockaddr_in6 from;
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@ -670,8 +672,8 @@ static void ping6(len_and_sockaddr *lsa)
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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msg.msg_control = control_buf;
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iov.iov_base = packet;
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iov.iov_len = sizeof(packet);
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iov.iov_base = G.rcv_packet;
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iov.iov_len = G.sizeof_rcv_packet;
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while (1) {
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int c;
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struct cmsghdr *mp;
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@ -694,7 +696,7 @@ static void ping6(len_and_sockaddr *lsa)
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move_from_unaligned_int(hoplimit, CMSG_DATA(mp));
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}
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}
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unpack6(packet, c, /*&from,*/ hoplimit);
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unpack6(G.rcv_packet, c, /*&from,*/ hoplimit);
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if (pingcount && nreceived >= pingcount)
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break;
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}
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@ -710,12 +712,20 @@ static void ping(len_and_sockaddr *lsa)
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}
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printf(": %d data bytes\n", datalen);
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G.sizeof_rcv_packet = datalen + MAXIPLEN + MAXICMPLEN;
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G.rcv_packet = xzalloc(G.sizeof_rcv_packet);
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#if ENABLE_PING6
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if (lsa->u.sa.sa_family == AF_INET6)
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if (lsa->u.sa.sa_family == AF_INET6) {
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/* +4 reserves a place for timestamp, which may end up sitting
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* _after_ packet. Saves one if() - see sendping4/6() */
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G.snd_packet = xzalloc(datalen + sizeof(struct icmp6_hdr) + 4);
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ping6(lsa);
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else
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} else
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#endif
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{
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G.snd_packet = xzalloc(datalen + ICMP_MINLEN + 4);
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ping4(lsa);
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}
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}
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static int common_ping_main(int opt, char **argv)
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