From: guy Date: Wed, 24 Mar 2004 00:04:04 +0000 (+0000) Subject: Add bounds checking. X-Git-Tag: tcpdump-3.8.2~23 X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/df238de7e7cc02a62001242722c3fecaef40c49c Add bounds checking. --- diff --git a/print-bgp.c b/print-bgp.c index aad4b6d5..669086b7 100644 --- a/print-bgp.c +++ b/print-bgp.c @@ -36,7 +36,7 @@ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/tcpdump/print-bgp.c,v 1.72.2.3 2004-01-16 10:07:20 hannes Exp $"; + "@(#) $Header: /tcpdump/master/tcpdump/print-bgp.c,v 1.72.2.4 2004-03-24 00:04:04 guy Exp $"; #endif #include @@ -450,11 +450,13 @@ decode_prefix4(const u_char *pptr, char *buf, u_int buflen) struct in_addr addr; u_int plen; + TCHECK(pptr[0]); plen = pptr[0]; if (32 < plen) return -1; memset(&addr, 0, sizeof(addr)); + TCHECK2(pptr[1], (plen + 7) / 8); memcpy(&addr, &pptr[1], (plen + 7) / 8); if (plen % 8) { ((u_char *)&addr)[(plen + 7) / 8 - 1] &= @@ -462,6 +464,9 @@ decode_prefix4(const u_char *pptr, char *buf, u_int buflen) } snprintf(buf, buflen, "%s/%d", getname((u_char *)&addr), plen); return 1 + (plen + 7) / 8; + +trunc: + return -2; } static int @@ -470,6 +475,7 @@ decode_labeled_prefix4(const u_char *pptr, char *buf, u_int buflen) struct in_addr addr; u_int plen; + TCHECK(pptr[0]); plen = pptr[0]; /* get prefix length */ /* this is one of the weirdnesses of rfc3107 @@ -486,6 +492,7 @@ decode_labeled_prefix4(const u_char *pptr, char *buf, u_int buflen) return -1; memset(&addr, 0, sizeof(addr)); + TCHECK2(pptr[4], (plen + 7) / 8); memcpy(&addr, &pptr[4], (plen + 7) / 8); if (plen % 8) { ((u_char *)&addr)[(plen + 7) / 8 - 1] &= @@ -499,6 +506,9 @@ decode_labeled_prefix4(const u_char *pptr, char *buf, u_int buflen) ((pptr[3]&1)==0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" ); return 4 + (plen + 7) / 8; + +trunc: + return -2; } /* RDs and RTs share the same semantics @@ -548,6 +558,7 @@ decode_rt_routing_info(const u_char *pptr, char *buf, u_int buflen) u_int8_t route_target[8]; u_int plen; + TCHECK(pptr[0]); plen = pptr[0]; /* get prefix length */ plen-=32; /* adjust prefix length */ @@ -556,6 +567,7 @@ decode_rt_routing_info(const u_char *pptr, char *buf, u_int buflen) return -1; memset(&route_target, 0, sizeof(route_target)); + TCHECK2(pptr[1], (plen + 7) / 8); memcpy(&route_target, &pptr[1], (plen + 7) / 8); if (plen % 8) { ((u_char *)&route_target)[(plen + 7) / 8 - 1] &= @@ -566,6 +578,9 @@ decode_rt_routing_info(const u_char *pptr, char *buf, u_int buflen) bgp_vpn_rd_print((u_char *)&route_target)); return 5 + (plen + 7) / 8; + +trunc: + return -2; } static int @@ -574,6 +589,7 @@ decode_labeled_vpn_prefix4(const u_char *pptr, char *buf, u_int buflen) struct in_addr addr; u_int plen; + TCHECK(pptr[0]); plen = pptr[0]; /* get prefix length */ plen-=(24+64); /* adjust prefixlen - labellength - RD len*/ @@ -582,6 +598,7 @@ decode_labeled_vpn_prefix4(const u_char *pptr, char *buf, u_int buflen) return -1; memset(&addr, 0, sizeof(addr)); + TCHECK2(pptr[12], (plen + 7) / 8); memcpy(&addr, &pptr[12], (plen + 7) / 8); if (plen % 8) { ((u_char *)&addr)[(plen + 7) / 8 - 1] &= @@ -596,15 +613,21 @@ decode_labeled_vpn_prefix4(const u_char *pptr, char *buf, u_int buflen) ((pptr[3]&1)==0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" ); return 12 + (plen + 7) / 8; + +trunc: + return -2; } static int decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen) { int plen,tlen,strlen,tlv_type,tlv_len,ttlv_len; + + TCHECK2(pptr[0], 2); plen=EXTRACT_16BITS(pptr); tlen=plen; pptr+=2; + TCHECK2(pptr[0],15); strlen=snprintf(buf, buflen, "RD: %s, CE-ID: %u, Label-Block Offset: %u, Label Base %u", bgp_vpn_rd_print(pptr), EXTRACT_16BITS(pptr+8), @@ -615,6 +638,9 @@ decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen) /* ok now the variable part - lets read out TLVs*/ while (tlen>0) { + if (tlen < 3) + return -1; + TCHECK2(pptr[0], 3); tlv_type=*pptr++; tlv_len=EXTRACT_16BITS(pptr); ttlv_len=tlv_len; @@ -627,6 +653,7 @@ decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen) tlv_len); ttlv_len=ttlv_len/8+1; /* how many bytes do we need to read ? */ while (ttlv_len>0) { + TCHECK(pptr[0]); strlen+=snprintf(buf+strlen,buflen-strlen, "%02x",*pptr++); ttlv_len--; } @@ -640,6 +667,9 @@ decode_labeled_vpn_l2(const u_char *pptr, char *buf, u_int buflen) tlen-=(tlv_len<<3); /* the tlv-length is expressed in bits so lets shift it tright */ } return plen+2; + +trunc: + return -2; } #ifdef INET6 @@ -649,11 +679,13 @@ decode_prefix6(const u_char *pd, char *buf, u_int buflen) struct in6_addr addr; u_int plen; + TCHECK(pd[0]); plen = pd[0]; if (128 < plen) return -1; memset(&addr, 0, sizeof(addr)); + TCHECK2(pd[1], (plen + 7) / 8); memcpy(&addr, &pd[1], (plen + 7) / 8); if (plen % 8) { addr.s6_addr[(plen + 7) / 8 - 1] &= @@ -661,6 +693,9 @@ decode_prefix6(const u_char *pd, char *buf, u_int buflen) } snprintf(buf, buflen, "%s/%d", getname6((u_char *)&addr), plen); return 1 + (plen + 7) / 8; + +trunc: + return -2; } static int @@ -669,6 +704,7 @@ decode_labeled_prefix6(const u_char *pptr, char *buf, u_int buflen) struct in6_addr addr; u_int plen; + TCHECK(pptr[0]); plen = pptr[0]; /* get prefix length */ plen-=24; /* adjust prefixlen - labellength */ @@ -676,6 +712,7 @@ decode_labeled_prefix6(const u_char *pptr, char *buf, u_int buflen) return -1; memset(&addr, 0, sizeof(addr)); + TCHECK2(pptr[4], (plen + 7) / 8); memcpy(&addr, &pptr[4], (plen + 7) / 8); if (plen % 8) { addr.s6_addr[(plen + 7) / 8 - 1] &= @@ -689,6 +726,9 @@ decode_labeled_prefix6(const u_char *pptr, char *buf, u_int buflen) ((pptr[3]&1)==0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" ); return 4 + (plen + 7) / 8; + +trunc: + return -2; } static int @@ -697,6 +737,7 @@ decode_labeled_vpn_prefix6(const u_char *pptr, char *buf, u_int buflen) struct in6_addr addr; u_int plen; + TCHECK(pptr[0]); plen = pptr[0]; /* get prefix length */ plen-=(24+64); /* adjust prefixlen - labellength - RD len*/ @@ -705,6 +746,7 @@ decode_labeled_vpn_prefix6(const u_char *pptr, char *buf, u_int buflen) return -1; memset(&addr, 0, sizeof(addr)); + TCHECK2(pptr[12], (plen + 7) / 8); memcpy(&addr, &pptr[12], (plen + 7) / 8); if (plen % 8) { addr.s6_addr[(plen + 7) / 8 - 1] &= @@ -719,10 +761,13 @@ decode_labeled_vpn_prefix6(const u_char *pptr, char *buf, u_int buflen) ((pptr[3]&1)==0) ? "(BOGUS: Bottom of Stack NOT set!)" : "(bottom)" ); return 12 + (plen + 7) / 8; + +trunc: + return -2; } #endif -static void +static int bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) { int i; @@ -744,8 +789,10 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case BGPTYPE_ORIGIN: if (len != 1) printf("invalid len"); - else + else { + TCHECK(*tptr); printf("%s", tok2str(bgp_origin_values, "Unknown Origin Typecode", tptr[0])); + } break; case BGPTYPE_AS_PATH: if (len % 2) { @@ -758,26 +805,34 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) } while (tptr < pptr + len) { + TCHECK(tptr[0]); printf("%s", tok2str(bgp_as_path_segment_open_values, "?", tptr[0])); for (i = 0; i < tptr[1] * 2; i += 2) { + TCHECK2(tptr[2 + i], 2); printf("%u ", EXTRACT_16BITS(&tptr[2 + i])); } + TCHECK(tptr[0]); printf("%s", tok2str(bgp_as_path_segment_close_values, "?", tptr[0])); + TCHECK(tptr[1]); tptr += 2 + tptr[1] * 2; } break; case BGPTYPE_NEXT_HOP: if (len != 4) printf("invalid len"); - else + else { + TCHECK2(tptr[0], 4); printf("%s", getname(tptr)); + } break; case BGPTYPE_MULTI_EXIT_DISC: case BGPTYPE_LOCAL_PREF: if (len != 4) printf("invalid len"); - else + else { + TCHECK2(tptr[0], 4); printf("%u", EXTRACT_32BITS(tptr)); + } break; case BGPTYPE_ATOMIC_AGGREGATE: if (len != 0) @@ -788,6 +843,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) printf("invalid len"); break; } + TCHECK2(tptr[0], 6); printf(" AS #%u, origin %s", EXTRACT_16BITS(tptr), getname(tptr + 2)); break; @@ -798,6 +854,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) } while (tlen>0) { u_int32_t comm; + TCHECK2(tptr[0], 4); comm = EXTRACT_32BITS(tptr); switch (comm) { case BGP_COMMUNITY_NO_EXPORT: @@ -825,10 +882,16 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) printf("invalid len"); break; } + TCHECK2(tptr[0], 4); printf("%s",getname(tptr)); break; case BGPTYPE_CLUSTER_LIST: + if (len % 4) { + printf("invalid len"); + break; + } while (tlen>0) { + TCHECK2(tptr[0], 4); printf("%s%s", getname(tptr), (tlen>4) ? ", " : ""); @@ -837,6 +900,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) } break; case BGPTYPE_MP_REACH_NLRI: + TCHECK2(tptr[0], 3); af = EXTRACT_16BITS(tptr); safi = tptr[2]; @@ -862,6 +926,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) tptr +=3; + TCHECK(tptr[0]); tlen = tptr[0]; tptr++; @@ -876,23 +941,38 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_UNIMULTICAST: case SAFNUM_LABUNICAST: case SAFNUM_RT_ROUTING_INFO: - printf("%s",getname(tptr)); - tlen -= sizeof(struct in_addr); - tptr += sizeof(struct in_addr); + if (tlen < (int)sizeof(struct in_addr)) { + printf("invalid len"); + tlen = 0; + } else { + TCHECK2(tptr[0], sizeof(struct in_addr)); + printf("%s",getname(tptr)); + tlen -= sizeof(struct in_addr); + tptr += sizeof(struct in_addr); + } break; case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: - printf("RD: %s, %s", + if (tlen < (int)(sizeof(struct in_addr)+BGP_VPN_RD_LEN)) { + printf("invalid len"); + tlen = 0; + } else { + TCHECK2(tptr[0], sizeof(struct in_addr)+BGP_VPN_RD_LEN); + printf("RD: %s, %s", bgp_vpn_rd_print(tptr), getname(tptr+BGP_VPN_RD_LEN)); - tlen -= (sizeof(struct in_addr)+BGP_VPN_RD_LEN); - tptr += (sizeof(struct in_addr)+BGP_VPN_RD_LEN); + tlen -= (sizeof(struct in_addr)+BGP_VPN_RD_LEN); + tptr += (sizeof(struct in_addr)+BGP_VPN_RD_LEN); + } break; default: - printf("no SAFI %u decoder",safi); + TCHECK2(tptr[0], tlen); + printf("no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr,"\n\t ",tlen); + tptr += tlen; + tlen = 0; break; } break; @@ -904,23 +984,38 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_UNIMULTICAST: case SAFNUM_LABUNICAST: case SAFNUM_RT_ROUTING_INFO: - printf("%s", getname6(tptr)); - tlen -= sizeof(struct in6_addr); - tptr += sizeof(struct in6_addr); + if (tlen < (int)sizeof(struct in6_addr)) { + printf("invalid len"); + tlen = 0; + } else { + TCHECK2(tptr[0], sizeof(struct in6_addr)); + printf("%s", getname6(tptr)); + tlen -= sizeof(struct in6_addr); + tptr += sizeof(struct in6_addr); + } break; case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: - printf("RD: %s, %s", + if (tlen < (int)(sizeof(struct in6_addr)+BGP_VPN_RD_LEN)) { + printf("invalid len"); + tlen = 0; + } else { + TCHECK2(tptr[0], sizeof(struct in6_addr)+BGP_VPN_RD_LEN); + printf("RD: %s, %s", bgp_vpn_rd_print(tptr), getname6(tptr+BGP_VPN_RD_LEN)); - tlen -= (sizeof(struct in6_addr)+BGP_VPN_RD_LEN); - tptr += (sizeof(struct in6_addr)+BGP_VPN_RD_LEN); + tlen -= (sizeof(struct in6_addr)+BGP_VPN_RD_LEN); + tptr += (sizeof(struct in6_addr)+BGP_VPN_RD_LEN); + } break; default: + TCHECK2(tptr[0], tlen); printf("no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr,"\n\t ",tlen); + tptr += tlen; + tlen = 0; break; } break; @@ -930,39 +1025,53 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: - printf("%s", getname(tptr)); - tlen -= (sizeof(struct in_addr)); - tptr += (sizeof(struct in_addr)); - break; + if (tlen < (int)sizeof(struct in_addr)) { + printf("invalid len"); + tlen = 0; + } else { + TCHECK2(tptr[0], sizeof(struct in_addr)); + printf("%s", getname(tptr)); + tlen -= (sizeof(struct in_addr)); + tptr += (sizeof(struct in_addr)); + } + break; default: + TCHECK2(tptr[0], tlen); printf("no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr,"\n\t ",tlen); + tptr += tlen; + tlen = 0; break; } break; default: + TCHECK2(tptr[0], tlen); printf("no AFI %u decoder",af); if (vflag <= 1) print_unknown_data(tptr,"\n\t ",tlen); + tptr += tlen; + tlen = 0; break; } } } tptr += tlen; + TCHECK(tptr[0]); snpa = tptr[0]; tptr++; if (snpa) { printf("\n\t %u SNPA", snpa); for (/*nothing*/; snpa > 0; snpa--) { + TCHECK(tptr[0]); printf("\n\t %d bytes", tptr[0]); tptr += tptr[0] + 1; } } else { - printf(", no SNPA"); + printf(", no SNPA"); } while (len - (tptr - pptr) > 0) { @@ -973,26 +1082,44 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_MULTICAST: case SAFNUM_UNIMULTICAST: advance = decode_prefix4(tptr, buf, sizeof(buf)); - if (advance >= 0) + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else printf("\n\t %s", buf); - else - printf("\n\t (illegal prefix length)"); break; case SAFNUM_LABUNICAST: advance = decode_labeled_prefix4(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: advance = decode_labeled_vpn_prefix4(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_RT_ROUTING_INFO: advance = decode_rt_routing_info(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; default: + TCHECK2(*(tptr-3),tlen); printf("\n\t no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1008,23 +1135,44 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_MULTICAST: case SAFNUM_UNIMULTICAST: advance = decode_prefix6(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_LABUNICAST: advance = decode_labeled_prefix6(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: advance = decode_labeled_vpn_prefix6(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_RT_ROUTING_INFO: advance = decode_rt_routing_info(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; default: + TCHECK2(*(tptr-3),tlen); printf("\n\t no SAFI %u decoder ",safi); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1040,12 +1188,18 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: advance = decode_labeled_vpn_l2(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; default: + TCHECK2(*tptr,tlen); printf("no SAFI %u decoder",safi); if (vflag <= 1) - print_unknown_data(tptr,"\n\t ",tlen); + print_unknown_data(tptr,"\n\t ",tlen); advance = 0; tptr = pptr + len; break; @@ -1054,6 +1208,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) default: + TCHECK2(*(tptr-3),tlen); printf("\n\t no AFI %u decoder ",af); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1066,6 +1221,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) break; case BGPTYPE_MP_UNREACH_NLRI: + TCHECK2(tptr[0], 3); af = EXTRACT_16BITS(tptr); safi = tptr[2]; @@ -1086,22 +1242,35 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_MULTICAST: case SAFNUM_UNIMULTICAST: advance = decode_prefix4(tptr, buf, sizeof(buf)); - if (advance >= 0) + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else printf("\n\t %s", buf); - else - printf("\n\t (illegal prefix length)"); break; case SAFNUM_LABUNICAST: advance = decode_labeled_prefix4(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: advance = decode_labeled_vpn_prefix4(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; default: + TCHECK2(*(tptr-3),tlen); printf("\n\t no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1118,19 +1287,35 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_MULTICAST: case SAFNUM_UNIMULTICAST: advance = decode_prefix6(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_LABUNICAST: advance = decode_labeled_prefix6(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; case SAFNUM_VPNUNICAST: case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: advance = decode_labeled_vpn_prefix6(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal prefix length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; default: + TCHECK2(*(tptr-3),tlen); printf("\n\t no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1147,9 +1332,15 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) case SAFNUM_VPNMULTICAST: case SAFNUM_VPNUNIMULTICAST: advance = decode_labeled_vpn_l2(tptr, buf, sizeof(buf)); - printf("\n\t %s", buf); + if (advance == -1) + printf("\n\t (illegal length)"); + else if (advance == -2) + goto trunc; + else + printf("\n\t %s", buf); break; default: + TCHECK2(*(tptr-3),tlen); printf("no SAFI %u decoder",safi); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1160,6 +1351,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) break; default: + TCHECK2(*(tptr-3),tlen); printf("\n\t no AFI %u decoder",af); if (vflag <= 1) print_unknown_data(tptr-3,"\n\t ",tlen); @@ -1178,6 +1370,8 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) } while (tlen>0) { u_int16_t extd_comm; + + TCHECK2(tptr[0], 2); extd_comm=EXTRACT_16BITS(tptr); printf("\n\t %s (0x%04x), Flags [%s]", @@ -1185,6 +1379,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) extd_comm, bittok2str(bgp_extd_comm_flag_values, "none", extd_comm)); + TCHECK2(*(tptr+2), 6); switch(extd_comm) { case BGP_EXT_COM_RT_0: case BGP_EXT_COM_RO_0: @@ -1245,6 +1440,7 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) break; default: + TCHECK2(*pptr,len); printf("\n\t no Attribute %u decoder",attr->bgpa_type); /* we have no decoder for the attribute */ if (vflag <= 1) print_unknown_data(pptr,"\n\t ",len); @@ -1252,6 +1448,10 @@ bgp_attr_print(const struct bgp_attr *attr, const u_char *pptr, int len) } if (vflag > 1 && len) /* omit zero length attributes*/ print_unknown_data(pptr,"\n\t ",len); + return 1; + +trunc: + return 0; } static void @@ -1392,12 +1592,14 @@ bgp_update_print(const u_char *dat, int length) while(i < 2 + len) { wpfx = decode_prefix4(&p[i], buf, sizeof(buf)); - if (wpfx >= 0) { - i += wpfx; - printf("\n\t %s", buf); - } else { + if (wpfx == -1) { printf("\n\t (illegal prefix length)"); break; + } else if (wpfx == -2) + goto trunc; + else { + i += wpfx; + printf("\n\t %s", buf); } } #endif @@ -1432,7 +1634,8 @@ bgp_update_print(const u_char *dat, int length) printf("+%x", bgpa.bgpa_flags & 0xf); printf("]: "); } - bgp_attr_print(&bgpa, &p[i + aoff], alen); + if (!bgp_attr_print(&bgpa, &p[i + aoff], alen)) + goto trunc; i += aoff + alen; } } @@ -1443,12 +1646,13 @@ bgp_update_print(const u_char *dat, int length) while (dat + length > p) { char buf[MAXHOSTNAMELEN + 100]; i = decode_prefix4(p, buf, sizeof(buf)); - if (i >= 0) { + if (i == -1) + printf("\n\t (illegal prefix length)"); + else if (i == -2) + goto trunc; + else { printf("\n\t %s", buf); p += i; - } else { - printf("\n\t (illegal prefix length)"); - break; } } } @@ -1545,7 +1749,7 @@ bgp_route_refresh_print(const u_char *pptr, int len) { return; } -static void +static int bgp_header_print(const u_char *dat, int length) { struct bgp bgp; @@ -1578,9 +1782,10 @@ bgp_header_print(const u_char *dat, int length) print_unknown_data(dat,"\n\t ",length); break; } - return; + return 1; trunc: printf("[|BGP]"); + return 0; } void @@ -1637,7 +1842,8 @@ bgp_print(const u_char *dat, int length) } if (TTEST2(p[0], hlen)) { - bgp_header_print(p, hlen); + if (!bgp_header_print(p, hlen)) + return; p += hlen; start = p; } else {