X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/38700c7f24646dfbc6ac0ed529d3ed727c545cd0..refs/pull/482/head:/print-pim.c diff --git a/print-pim.c b/print-pim.c index a8bcdcf8..ce4b2afd 100644 --- a/print-pim.c +++ b/print-pim.c @@ -23,13 +23,15 @@ #include "config.h" #endif -#include +#include -#include "interface.h" +#include "netdissect.h" #include "addrtoname.h" #include "extract.h" #include "ip.h" +#include "ip6.h" +#include "ipproto.h" #define PIMV1_TYPE_QUERY 0 #define PIMV1_TYPE_REGISTER 1 @@ -133,7 +135,7 @@ struct pim { u_short pim_cksum; /* IP style check sum */ }; -static void pimv2_print(netdissect_options *, register const u_char *bp, register u_int len, u_int cksum); +static void pimv2_print(netdissect_options *, register const u_char *bp, register u_int len, const u_char *); static void pimv1_join_prune_print(netdissect_options *ndo, @@ -414,10 +416,10 @@ trunc: void pim_print(netdissect_options *ndo, - register const u_char *bp, register u_int len, u_int cksum) + register const u_char *bp, register u_int len, const u_char *bp2) { register const u_char *ep; - register struct pim *pim = (struct pim *)bp; + register const struct pim *pim = (const struct pim *)bp; ep = (const u_char *)ndo->ndo_snapend; if (bp >= ep) @@ -439,7 +441,7 @@ pim_print(netdissect_options *ndo, PIM_VER(pim->pim_typever), len, tok2str(pimv2_type_values,"Unknown Type",PIM_TYPE(pim->pim_typever)))); - pimv2_print(ndo, bp, len, cksum); + pimv2_print(ndo, bp, len, bp2); } break; default: @@ -533,12 +535,10 @@ pimv2_addr_print(netdissect_options *ndo, af = AF_INET; len = sizeof(struct in_addr); break; -#ifdef INET6 case 2: af = AF_INET6; len = sizeof(struct in6_addr); break; -#endif default: return -1; } @@ -550,11 +550,9 @@ pimv2_addr_print(netdissect_options *ndo, case sizeof(struct in_addr): af = AF_INET; break; -#ifdef INET6 case sizeof(struct in6_addr): af = AF_INET6; break; -#endif default: return -1; break; @@ -571,12 +569,10 @@ pimv2_addr_print(netdissect_options *ndo, if (!silent) ND_PRINT((ndo, "%s", ipaddr_string(ndo, bp))); } -#ifdef INET6 else if (af == AF_INET6) { if (!silent) ND_PRINT((ndo, "%s", ip6addr_string(ndo, bp))); } -#endif return hdrlen + len; case pimv2_group: case pimv2_source: @@ -588,7 +584,6 @@ pimv2_addr_print(netdissect_options *ndo, ND_PRINT((ndo, "/%u", bp[1])); } } -#ifdef INET6 else if (af == AF_INET6) { if (!silent) { ND_PRINT((ndo, "%s", ip6addr_string(ndo, bp + 2))); @@ -596,7 +591,6 @@ pimv2_addr_print(netdissect_options *ndo, ND_PRINT((ndo, "/%u", bp[1])); } } -#endif if (bp[0] && !silent) { if (at == pimv2_group) { ND_PRINT((ndo, "(0x%02x)", bp[0])); @@ -619,13 +613,45 @@ trunc: return -1; } +enum checksum_status { + CORRECT, + INCORRECT, + UNVERIFIED +}; + +static enum checksum_status +pimv2_check_checksum(const u_char *bp, const u_char *bp2, u_int len) +{ + const struct ip *ip; + u_int cksum; + + ip = (const struct ip *)bp2; + if (IP_V(ip) == 4) { + struct cksum_vec vec[1]; + + vec[0].ptr = bp; + vec[0].len = len; + cksum = in_cksum(vec, 1); + return (cksum ? INCORRECT : CORRECT); + } else if (IP_V(ip) == 6) { + const struct ip6_hdr *ip6; + + ip6 = (const struct ip6_hdr *)bp2; + cksum = nextproto6_cksum(ip6, bp, len, len, IPPROTO_PIM); + return (cksum ? INCORRECT : CORRECT); + } else { + return (UNVERIFIED); + } +} + static void pimv2_print(netdissect_options *ndo, - register const u_char *bp, register u_int len, u_int cksum) + register const u_char *bp, register u_int len, const u_char *bp2) { register const u_char *ep; - register struct pim *pim = (struct pim *)bp; + register const struct pim *pim = (const struct pim *)bp; int advance; + enum checksum_status cksum_status; ep = (const u_char *)ndo->ndo_snapend; if (bp >= ep) @@ -641,7 +667,41 @@ pimv2_print(netdissect_options *ndo, if (EXTRACT_16BITS(&pim->pim_cksum) == 0) { ND_PRINT((ndo, "(unverified)")); } else { - ND_PRINT((ndo, "(%scorrect)", ND_TTEST2(bp[0], len) && cksum ? "in" : "" )); + if (PIM_TYPE(pim->pim_typever) == PIMV2_TYPE_REGISTER) { + /* + * The checksum only covers the packet header, + * not the encapsulated packet. + */ + cksum_status = pimv2_check_checksum(bp, bp2, 8); + if (cksum_status == INCORRECT) { + /* + * To quote RFC 4601, "For interoperability + * reasons, a message carrying a checksum + * calculated over the entire PIM Register + * message should also be accepted." + */ + cksum_status = pimv2_check_checksum(bp, bp2, len); + } + } else { + /* + * The checksum covers the entire packet. + */ + cksum_status = pimv2_check_checksum(bp, bp2, len); + } + switch (cksum_status) { + + case CORRECT: + ND_PRINT((ndo, "(correct)")); + break; + + case INCORRECT: + ND_PRINT((ndo, "(incorrect)")); + break; + + case UNVERIFIED: + ND_PRINT((ndo, "(unverified)")); + break; + } } switch (PIM_TYPE(pim->pim_typever)) { @@ -718,8 +778,6 @@ pimv2_print(netdissect_options *ndo, if (ndo->ndo_vflag > 1) { const u_char *ptr = bp; while (ptr < (bp+olen)) { - int advance; - ND_PRINT((ndo, "\n\t ")); advance = pimv2_addr_print(ndo, ptr, pimv2_unicast, 0); if (advance < 0) { @@ -745,7 +803,7 @@ pimv2_print(netdissect_options *ndo, case PIMV2_TYPE_REGISTER: { - struct ip *ip; + const struct ip *ip; ND_TCHECK2(*(bp + 4), PIMV2_REGISTER_FLAG_LEN); @@ -756,7 +814,7 @@ pimv2_print(netdissect_options *ndo, bp += 8; len -= 8; /* encapsulated multicast packet */ - ip = (struct ip *)bp; + ip = (const struct ip *)bp; switch (IP_V(ip)) { case 0: /* Null header */ ND_PRINT((ndo, "IP-Null-header %s > %s",