X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/8d0935ca9b4dafd336bddd69f10ae495fd004e93..309ca62193772fd8ba532fd413b51a61be0c741e:/print-tcp.c diff --git a/print-tcp.c b/print-tcp.c index 7893f61d..88b46157 100644 --- a/print-tcp.c +++ b/print-tcp.c @@ -129,63 +129,9 @@ static int tcp_cksum(register const struct ip *ip, register const struct tcphdr *tp, register u_int len) { - union phu { - struct phdr { - u_int32_t src; - u_int32_t dst; - u_char mbz; - u_char proto; - u_int16_t len; - } ph; - u_int16_t pa[6]; - } phu; - const u_int16_t *sp; - - /* pseudo-header.. */ - phu.ph.len = htons((u_int16_t)len); - phu.ph.mbz = 0; - phu.ph.proto = IPPROTO_TCP; - memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t)); - if (IP_HL(ip) == 5) - memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t)); - else - phu.ph.dst = ip_finddst(ip); - - sp = &phu.pa[0]; - return in_cksum((u_short *)tp, len, - sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]); -} - -#ifdef INET6 -static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp, - u_int len) -{ - size_t i; - u_int32_t sum = 0; - union { - struct { - struct in6_addr ph_src; - struct in6_addr ph_dst; - u_int32_t ph_len; - u_int8_t ph_zero[3]; - u_int8_t ph_nxt; - } ph; - u_int16_t pa[20]; - } phu; - - /* pseudo-header */ - memset(&phu, 0, sizeof(phu)); - phu.ph.ph_src = ip6->ip6_src; - phu.ph.ph_dst = ip6->ip6_dst; - phu.ph.ph_len = htonl(len); - phu.ph.ph_nxt = IPPROTO_TCP; - - for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++) - sum += phu.pa[i]; - - return in_cksum((u_short *)tp, len, sum); + return (nextproto4_cksum(ip, (const u_int8_t *)tp, len, + IPPROTO_TCP)); } -#endif void tcp_print(register const u_char *bp, register u_int length, @@ -325,7 +271,6 @@ tcp_print(register const u_char *bp, register u_int length, * both directions). */ #ifdef INET6 - memset(&tha, 0, sizeof(tha)); rev = 0; if (ip6) { src = &ip6->ip6_src; @@ -346,6 +291,27 @@ tcp_print(register const u_char *bp, register u_int length, tha.port = sport << 16 | dport; } } else { + /* + * Zero out the tha structure; the src and dst + * fields are big enough to hold an IPv6 + * address, but we only have IPv4 addresses + * and thus must clear out the remaining 124 + * bits. + * + * XXX - should we just clear those bytes after + * copying the IPv4 addresses, rather than + * zeroing out the entire structure and then + * overwriting some of the zeroes? + * + * XXX - this could fail if we see TCP packets + * with an IPv6 address with the lower 124 bits + * all zero and also see TCP packes with an + * IPv4 address with the same 32 bits as the + * upper 32 bits of the IPv6 address in question. + * Can that happen? Is it likely enough to be + * an issue? + */ + memset(&tha, 0, sizeof(tha)); src = &ip->ip_src; dst = &ip->ip_dst; if (sport > dport) @@ -424,34 +390,40 @@ tcp_print(register const u_char *bp, register u_int length, return; } - if (IP_V(ip) == 4 && vflag && !Kflag && !fragmented) { + if (vflag && !Kflag && !fragmented) { + /* Check the checksum, if possible. */ u_int16_t sum, tcp_sum; - if (TTEST2(tp->th_sport, length)) { - sum = tcp_cksum(ip, tp, length); - (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum)); - if (sum != 0) { + if (IP_V(ip) == 4) { + if (TTEST2(tp->th_sport, length)) { + sum = tcp_cksum(ip, tp, length); tcp_sum = EXTRACT_16BITS(&tp->th_sum); - (void)printf(" (incorrect -> 0x%04x)",in_cksum_shouldbe(tcp_sum, sum)); - } else - (void)printf(" (correct)"); + + (void)printf(", cksum 0x%04x", tcp_sum); + if (sum != 0) + (void)printf(" (incorrect -> 0x%04x)", + in_cksum_shouldbe(tcp_sum, sum)); + else + (void)printf(" (correct)"); + } } - } #ifdef INET6 - if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !Kflag && !fragmented) { - u_int16_t sum,tcp_sum; - if (TTEST2(tp->th_sport, length)) { - sum = tcp6_cksum(ip6, tp, length); - (void)printf(", cksum 0x%04x",EXTRACT_16BITS(&tp->th_sum)); - if (sum != 0) { + else if (IP_V(ip) == 6 && ip6->ip6_plen) { + if (TTEST2(tp->th_sport, length)) { + sum = nextproto6_cksum(ip6, (const u_int8_t *)tp, length, IPPROTO_TCP); tcp_sum = EXTRACT_16BITS(&tp->th_sum); - (void)printf(" (incorrect -> 0x%04x)",in_cksum_shouldbe(tcp_sum, sum)); - } else - (void)printf(" (correct)"); + (void)printf(", cksum 0x%04x", tcp_sum); + if (sum != 0) + (void)printf(" (incorrect -> 0x%04x)", + in_cksum_shouldbe(tcp_sum, sum)); + else + (void)printf(" (correct)"); + + } } - } #endif + } length -= hlen; if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { @@ -692,6 +664,8 @@ tcp_print(register const u_char *bp, register u_int length, ns_print(bp + 2, length - 2, 0); } else if (sport == MSDP_PORT || dport == MSDP_PORT) { msdp_print(bp, length); + } else if (sport == RPKI_RTR_PORT || dport == RPKI_RTR_PORT) { + rpki_rtr_print(bp, length); } else if (length > 0 && (sport == LDP_PORT || dport == LDP_PORT)) { ldp_print(bp, length); @@ -790,7 +764,7 @@ tcp_verify_signature(const struct ip *ip, const struct tcphdr *tp, ip6 = (struct ip6_hdr *)ip; MD5_Update(&ctx, (char *)&ip6->ip6_src, sizeof(ip6->ip6_src)); MD5_Update(&ctx, (char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst)); - len32 = htonl(ntohs(ip6->ip6_plen)); + len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen)); MD5_Update(&ctx, (char *)&len32, sizeof(len32)); nxt = 0; MD5_Update(&ctx, (char *)&nxt, sizeof(nxt));