X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/07a7f33ba3ff346b9ce31772645a06980baca907..refs/pull/1034/head:/print-gre.c?ds=sidebyside diff --git a/print-gre.c b/print-gre.c index 09b2be11..136fb69d 100644 --- a/print-gre.c +++ b/print-gre.c @@ -39,8 +39,7 @@ #include "netdissect-stdinc.h" -#include - +#define ND_LONGJMP_FROM_TCHECK #include "netdissect.h" #include "addrtostr.h" #include "extract.h" @@ -52,7 +51,6 @@ #define GRE_KP 0x2000 /* key present */ #define GRE_SP 0x1000 /* sequence# present */ #define GRE_sP 0x0800 /* source routing */ -#define GRE_RECRS 0x0700 /* recursion count */ #define GRE_AP 0x0080 /* acknowledgment# present */ static const struct tok gre_flag_values[] = { @@ -61,11 +59,11 @@ static const struct tok gre_flag_values[] = { { GRE_KP, "key present"}, { GRE_SP, "sequence# present"}, { GRE_sP, "source routing present"}, - { GRE_RECRS, "recursion count"}, { GRE_AP, "ack present"}, { 0, NULL } }; +#define GRE_RECRS_MASK 0x0700 /* recursion count */ #define GRE_VERS_MASK 0x0007 /* protocol version */ /* source route entry types */ @@ -81,21 +79,20 @@ static int gre_sre_asn_print(netdissect_options *, uint8_t, uint8_t, const u_cha void gre_print(netdissect_options *ndo, const u_char *bp, u_int length) { - u_int len = length, vers; + u_int vers; ndo->ndo_protocol = "gre"; - ND_TCHECK_2(bp); - if (len < 2) - goto trunc; + nd_print_protocol_caps(ndo); + ND_ICHECK_U(length, <, 2); vers = GET_BE_U_2(bp) & GRE_VERS_MASK; - ND_PRINT("GREv%u",vers); + ND_PRINT("v%u",vers); switch(vers) { case 0: - gre_print_0(ndo, bp, len); + gre_print_0(ndo, bp, length); break; case 1: - gre_print_1(ndo, bp, len); + gre_print_1(ndo, bp, length); break; default: ND_PRINT(" ERROR: unknown-version"); @@ -103,9 +100,8 @@ gre_print(netdissect_options *ndo, const u_char *bp, u_int length) } return; -trunc: - nd_print_trunc(ndo); - return; +invalid: + nd_print_invalid(ndo); } static void @@ -114,7 +110,7 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length) u_int len = length; uint16_t flags, prot; - /* 16 bits ND_TCHECKed in gre_print() */ + ND_ICHECK_U(len, <, 2); flags = GET_BE_U_2(bp); if (ndo->ndo_vflag) ND_PRINT(", Flags [%s]", @@ -123,43 +119,36 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length) len -= 2; bp += 2; - ND_TCHECK_2(bp); - if (len < 2) - goto trunc; + ND_ICHECK_U(len, <, 2); prot = GET_BE_U_2(bp); len -= 2; bp += 2; if ((flags & GRE_CP) | (flags & GRE_RP)) { - ND_TCHECK_2(bp); - if (len < 2) - goto trunc; + uint16_t sum; + + ND_ICHECK_U(len, <, 2); + sum = GET_BE_U_2(bp); if (ndo->ndo_vflag) - ND_PRINT(", sum 0x%x", GET_BE_U_2(bp)); + ND_PRINT(", sum 0x%x", sum); bp += 2; len -= 2; - ND_TCHECK_2(bp); - if (len < 2) - goto trunc; + ND_ICHECK_U(len, <, 2); ND_PRINT(", off 0x%x", GET_BE_U_2(bp)); bp += 2; len -= 2; } if (flags & GRE_KP) { - ND_TCHECK_4(bp); - if (len < 4) - goto trunc; + ND_ICHECK_U(len, <, 4); ND_PRINT(", key=0x%x", GET_BE_U_4(bp)); bp += 4; len -= 4; } if (flags & GRE_SP) { - ND_TCHECK_4(bp); - if (len < 4) - goto trunc; + ND_ICHECK_U(len, <, 4); ND_PRINT(", seq %u", GET_BE_U_4(bp)); bp += 4; len -= 4; @@ -171,9 +160,7 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length) uint8_t sreoff; uint8_t srelen; - ND_TCHECK_4(bp); - if (len < 4) - goto trunc; + ND_ICHECK_U(len, <, 4); af = GET_BE_U_2(bp); sreoff = GET_U_1(bp + 2); srelen = GET_U_1(bp + 3); @@ -184,10 +171,9 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length) break; if (!gre_sre_print(ndo, af, sreoff, srelen, bp, len)) - goto trunc; + goto invalid; - if (len < srelen) - goto trunc; + ND_ICHECK_U(len, <, srelen); bp += srelen; len -= srelen; } @@ -231,8 +217,8 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length) } return; -trunc: - nd_print_trunc(ndo); +invalid: + nd_print_invalid(ndo); } static void @@ -241,7 +227,7 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length) u_int len = length; uint16_t flags, prot; - /* 16 bits ND_TCHECKed in gre_print() */ + ND_ICHECK_U(len, <, 2); flags = GET_BE_U_2(bp); len -= 2; bp += 2; @@ -250,9 +236,7 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length) ND_PRINT(", Flags [%s]", bittok2str(gre_flag_values,"none",flags)); - ND_TCHECK_2(bp); - if (len < 2) - goto trunc; + ND_ICHECK_U(len, <, 2); prot = GET_BE_U_2(bp); len -= 2; bp += 2; @@ -261,9 +245,7 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length) if (flags & GRE_KP) { uint32_t k; - ND_TCHECK_4(bp); - if (len < 4) - goto trunc; + ND_ICHECK_U(len, <, 4); k = GET_BE_U_4(bp); ND_PRINT(", call %u", k & 0xffff); len -= 4; @@ -271,18 +253,14 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length) } if (flags & GRE_SP) { - ND_TCHECK_4(bp); - if (len < 4) - goto trunc; + ND_ICHECK_U(len, <, 4); ND_PRINT(", seq %u", GET_BE_U_4(bp)); bp += 4; len -= 4; } if (flags & GRE_AP) { - ND_TCHECK_4(bp); - if (len < 4) - goto trunc; + ND_ICHECK_U(len, <, 4); ND_PRINT(", ack %u", GET_BE_U_4(bp)); bp += 4; len -= 4; @@ -315,8 +293,8 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length) } return; -trunc: - nd_print_trunc(ndo); +invalid: + nd_print_invalid(ndo); } static int @@ -352,22 +330,21 @@ gre_sre_ip_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen, if (sreoff & 3) { ND_PRINT(", badoffset=%u", sreoff); - return (1); + goto invalid; } if (srelen & 3) { ND_PRINT(", badlength=%u", srelen); - return (1); + goto invalid; } if (sreoff >= srelen) { ND_PRINT(", badoff/len=%u/%u", sreoff, srelen); - return (1); + goto invalid; } while (srelen != 0) { - ND_TCHECK_4(bp); - if (len < 4) - return (0); + ND_ICHECK_U(len, <, 4); + ND_TCHECK_LEN(bp, sizeof(nd_ipv4)); addrtostr(bp, buf, sizeof(buf)); ND_PRINT(" %s%s", ((bp - up) == sreoff) ? "*" : "", buf); @@ -376,8 +353,9 @@ gre_sre_ip_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen, len -= 4; srelen -= 4; } - return (1); -trunc: + return 1; + +invalid: return 0; } @@ -389,21 +367,19 @@ gre_sre_asn_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen, if (sreoff & 1) { ND_PRINT(", badoffset=%u", sreoff); - return (1); + goto invalid; } if (srelen & 1) { ND_PRINT(", badlength=%u", srelen); - return (1); + goto invalid; } if (sreoff >= srelen) { ND_PRINT(", badoff/len=%u/%u", sreoff, srelen); - return (1); + goto invalid; } while (srelen != 0) { - ND_TCHECK_2(bp); - if (len < 2) - return (0); + ND_ICHECK_U(len, <, 2); ND_PRINT(" %s%x", ((bp - up) == sreoff) ? "*" : "", GET_BE_U_2(bp)); @@ -412,7 +388,8 @@ gre_sre_asn_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen, len -= 2; srelen -= 2; } - return (1); -trunc: + return 1; + +invalid: return 0; }