X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/d8acd8f5d0d7cac4881b5552eca5dc40a5d3c0d1..d7b497cac78b6e22a66a6bae9bdec60a8044f67a:/print-gre.c diff --git a/print-gre.c b/print-gre.c index 66a40f94..672ed956 100644 --- a/print-gre.c +++ b/print-gre.c @@ -31,30 +31,24 @@ * POSSIBILITY OF SUCH DAMAGE. */ +/* \summary: Generic Routing Encapsulation (GRE) printer */ + /* - * tcpdump filter for GRE - Generic Routing Encapsulation + * netdissect printer for GRE - Generic Routing Encapsulation * RFC1701 (GRE), RFC1702 (GRE IPv4), and RFC2637 (Enhanced GRE) */ -#ifndef lint -static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/tcpdump/print-gre.c,v 1.28 2005-04-06 21:32:39 mcr Exp $ (LBL)"; -#endif - #ifdef HAVE_CONFIG_H #include "config.h" #endif -#include +#include -#include #include -#include "interface.h" -#include "addrtoname.h" +#include "netdissect.h" +#include "addrtostr.h" #include "extract.h" - -#include "ip.h" #include "ethertype.h" static const char tstr[] = "[|gre]"; @@ -69,9 +63,9 @@ static const char tstr[] = "[|gre]"; static const struct tok gre_flag_values[] = { { GRE_CP, "checksum present"}, - { GRE_RP, "routing present"}, - { GRE_KP, "key present"}, - { GRE_SP, "sequence# present"}, + { GRE_RP, "routing present"}, + { GRE_KP, "key present"}, + { GRE_SP, "sequence# present"}, { GRE_sP, "source routing present"}, { GRE_RECRS, "recursion count"}, { GRE_AP, "ack present"}, @@ -84,108 +78,118 @@ static const struct tok gre_flag_values[] = { #define GRESRE_IP 0x0800 /* IP */ #define GRESRE_ASN 0xfffe /* ASN */ -void gre_print_0(const u_char *, u_int); -void gre_print_1(const u_char *, u_int); -void gre_sre_print(u_int16_t, u_int8_t, u_int8_t, const u_char *, u_int); -void gre_sre_ip_print(u_int8_t, u_int8_t, const u_char *, u_int); -void gre_sre_asn_print(u_int8_t, u_int8_t, const u_char *, u_int); +static void gre_print_0(netdissect_options *, const u_char *, u_int); +static void gre_print_1(netdissect_options *, const u_char *, u_int); +static int gre_sre_print(netdissect_options *, uint16_t, uint8_t, uint8_t, const u_char *, u_int); +static int gre_sre_ip_print(netdissect_options *, uint8_t, uint8_t, const u_char *, u_int); +static int gre_sre_asn_print(netdissect_options *, uint8_t, uint8_t, const u_char *, u_int); void -gre_print(const u_char *bp, u_int length) +gre_print(netdissect_options *ndo, const u_char *bp, u_int length) { u_int len = length, vers; - if (len < 2) { - printf("%s", tstr); - return; - } - vers = EXTRACT_16BITS(bp) & GRE_VERS_MASK; - printf("GREv%u",vers); + ND_TCHECK_2(bp); + if (len < 2) + goto trunc; + vers = EXTRACT_BE_U_2(bp) & GRE_VERS_MASK; + ND_PRINT((ndo, "GREv%u",vers)); switch(vers) { case 0: - gre_print_0(bp, len); + gre_print_0(ndo, bp, len); break; case 1: - gre_print_1(bp, len); + gre_print_1(ndo, bp, len); break; default: - printf(" ERROR: unknown-version"); + ND_PRINT((ndo, " ERROR: unknown-version")); break; } - return; + return; +trunc: + ND_PRINT((ndo, "%s", tstr)); + return; } -void -gre_print_0(const u_char *bp, u_int length) +static void +gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length) { u_int len = length; - u_int16_t flags, prot; + uint16_t flags, prot; - flags = EXTRACT_16BITS(bp); - if (vflag) - printf(", Flags [%s]", - bittok2str(gre_flag_values,"none",flags)); + /* 16 bits ND_TCHECKed in gre_print() */ + flags = EXTRACT_BE_U_2(bp); + if (ndo->ndo_vflag) + ND_PRINT((ndo, ", Flags [%s]", + bittok2str(gre_flag_values,"none",flags))); len -= 2; bp += 2; + ND_TCHECK_2(bp); if (len < 2) goto trunc; - prot = EXTRACT_16BITS(bp); + prot = EXTRACT_BE_U_2(bp); len -= 2; bp += 2; if ((flags & GRE_CP) | (flags & GRE_RP)) { + ND_TCHECK_2(bp); if (len < 2) goto trunc; - if (vflag) - printf(", sum 0x%x", EXTRACT_16BITS(bp)); + if (ndo->ndo_vflag) + ND_PRINT((ndo, ", sum 0x%x", EXTRACT_BE_U_2(bp))); bp += 2; len -= 2; + ND_TCHECK_2(bp); if (len < 2) goto trunc; - printf(", off 0x%x", EXTRACT_16BITS(bp)); + ND_PRINT((ndo, ", off 0x%x", EXTRACT_BE_U_2(bp))); bp += 2; len -= 2; } if (flags & GRE_KP) { + ND_TCHECK_4(bp); if (len < 4) goto trunc; - printf(", key=0x%x", EXTRACT_32BITS(bp)); + ND_PRINT((ndo, ", key=0x%x", EXTRACT_BE_U_4(bp))); bp += 4; len -= 4; } if (flags & GRE_SP) { + ND_TCHECK_4(bp); if (len < 4) goto trunc; - printf(", seq %u", EXTRACT_32BITS(bp)); + ND_PRINT((ndo, ", seq %u", EXTRACT_BE_U_4(bp))); bp += 4; len -= 4; } if (flags & GRE_RP) { for (;;) { - u_int16_t af; - u_int8_t sreoff; - u_int8_t srelen; + uint16_t af; + uint8_t sreoff; + uint8_t srelen; + ND_TCHECK_4(bp); if (len < 4) goto trunc; - af = EXTRACT_16BITS(bp); - sreoff = *(bp + 2); - srelen = *(bp + 3); + af = EXTRACT_BE_U_2(bp); + sreoff = EXTRACT_U_1(bp + 2); + srelen = EXTRACT_U_1(bp + 3); bp += 4; len -= 4; if (af == 0 && srelen == 0) break; - gre_sre_print(af, sreoff, srelen, bp, len); + if (!gre_sre_print(ndo, af, sreoff, srelen, bp, len)) + goto trunc; if (len < srelen) goto trunc; @@ -194,212 +198,227 @@ gre_print_0(const u_char *bp, u_int length) } } - if (eflag) - printf(", proto %s (0x%04x)", + if (ndo->ndo_eflag) + ND_PRINT((ndo, ", proto %s (0x%04x)", tok2str(ethertype_values,"unknown",prot), - prot); + prot)); - printf(", length %u",length); + ND_PRINT((ndo, ", length %u",length)); - if (vflag < 1) - printf(": "); /* put in a colon as protocol demarc */ + if (ndo->ndo_vflag < 1) + ND_PRINT((ndo, ": ")); /* put in a colon as protocol demarc */ else - printf("\n\t"); /* if verbose go multiline */ + ND_PRINT((ndo, "\n\t")); /* if verbose go multiline */ switch (prot) { case ETHERTYPE_IP: - ip_print(gndo, bp, len); + ip_print(ndo, bp, len); break; -#ifdef INET6 case ETHERTYPE_IPV6: - ip6_print(gndo, bp, len); + ip6_print(ndo, bp, len); break; -#endif case ETHERTYPE_MPLS: - mpls_print(bp, len); + mpls_print(ndo, bp, len); break; case ETHERTYPE_IPX: - ipx_print(bp, len); + ipx_print(ndo, bp, len); break; case ETHERTYPE_ATALK: - atalk_print(bp, len); + atalk_print(ndo, bp, len); break; case ETHERTYPE_GRE_ISO: - isoclns_print(bp, len, len); + isoclns_print(ndo, bp, len); break; case ETHERTYPE_TEB: - ether_print(gndo, bp, len, len, NULL, NULL); + ether_print(ndo, bp, len, ndo->ndo_snapend - bp, NULL, NULL); break; default: - printf("gre-proto-0x%x", prot); + ND_PRINT((ndo, "gre-proto-0x%x", prot)); } return; trunc: - printf("%s", tstr); + ND_PRINT((ndo, "%s", tstr)); } -void -gre_print_1(const u_char *bp, u_int length) +static void +gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length) { u_int len = length; - u_int16_t flags, prot; + uint16_t flags, prot; - flags = EXTRACT_16BITS(bp); + /* 16 bits ND_TCHECKed in gre_print() */ + flags = EXTRACT_BE_U_2(bp); len -= 2; bp += 2; - if (vflag) - printf(", Flags [%s]", - bittok2str(gre_flag_values,"none",flags)); + if (ndo->ndo_vflag) + ND_PRINT((ndo, ", Flags [%s]", + bittok2str(gre_flag_values,"none",flags))); + ND_TCHECK_2(bp); if (len < 2) goto trunc; - prot = EXTRACT_16BITS(bp); + prot = EXTRACT_BE_U_2(bp); len -= 2; bp += 2; if (flags & GRE_KP) { - u_int32_t k; + uint32_t k; + ND_TCHECK_4(bp); if (len < 4) goto trunc; - k = EXTRACT_32BITS(bp); - printf(", call %d", k & 0xffff); + k = EXTRACT_BE_U_4(bp); + ND_PRINT((ndo, ", call %d", k & 0xffff)); len -= 4; bp += 4; } if (flags & GRE_SP) { + ND_TCHECK_4(bp); if (len < 4) goto trunc; - printf(", seq %u", EXTRACT_32BITS(bp)); + ND_PRINT((ndo, ", seq %u", EXTRACT_BE_U_4(bp))); bp += 4; len -= 4; } if (flags & GRE_AP) { + ND_TCHECK_4(bp); if (len < 4) goto trunc; - printf(", ack %u", EXTRACT_32BITS(bp)); + ND_PRINT((ndo, ", ack %u", EXTRACT_BE_U_4(bp))); bp += 4; len -= 4; } if ((flags & GRE_SP) == 0) - printf(", no-payload"); + ND_PRINT((ndo, ", no-payload")); - if (eflag) - printf(", proto %s (0x%04x)", + if (ndo->ndo_eflag) + ND_PRINT((ndo, ", proto %s (0x%04x)", tok2str(ethertype_values,"unknown",prot), - prot); + prot)); - printf(", length %u",length); + ND_PRINT((ndo, ", length %u",length)); if ((flags & GRE_SP) == 0) return; - if (vflag < 1) - printf(": "); /* put in a colon as protocol demarc */ + if (ndo->ndo_vflag < 1) + ND_PRINT((ndo, ": ")); /* put in a colon as protocol demarc */ else - printf("\n\t"); /* if verbose go multiline */ + ND_PRINT((ndo, "\n\t")); /* if verbose go multiline */ switch (prot) { case ETHERTYPE_PPP: - ppp_print(bp, len); + ppp_print(ndo, bp, len); break; default: - printf("gre-proto-0x%x", prot); + ND_PRINT((ndo, "gre-proto-0x%x", prot)); break; } return; trunc: - printf("%s", tstr); + ND_PRINT((ndo, "%s", tstr)); } -void -gre_sre_print(u_int16_t af, u_int8_t sreoff, u_int8_t srelen, - const u_char *bp, u_int len) +static int +gre_sre_print(netdissect_options *ndo, uint16_t af, uint8_t sreoff, + uint8_t srelen, const u_char *bp, u_int len) { + int ret; + switch (af) { case GRESRE_IP: - printf(", (rtaf=ip"); - gre_sre_ip_print(sreoff, srelen, bp, len); - printf(") "); + ND_PRINT((ndo, ", (rtaf=ip")); + ret = gre_sre_ip_print(ndo, sreoff, srelen, bp, len); + ND_PRINT((ndo, ")")); break; case GRESRE_ASN: - printf(", (rtaf=asn"); - gre_sre_asn_print(sreoff, srelen, bp, len); - printf(") "); + ND_PRINT((ndo, ", (rtaf=asn")); + ret = gre_sre_asn_print(ndo, sreoff, srelen, bp, len); + ND_PRINT((ndo, ")")); break; default: - printf(", (rtaf=0x%x) ", af); + ND_PRINT((ndo, ", (rtaf=0x%x)", af)); + ret = 1; } + return (ret); } -void -gre_sre_ip_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len) + +static int +gre_sre_ip_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen, + const u_char *bp, u_int len) { - struct in_addr a; const u_char *up = bp; + char buf[INET_ADDRSTRLEN]; if (sreoff & 3) { - printf(", badoffset=%u", sreoff); - return; + ND_PRINT((ndo, ", badoffset=%u", sreoff)); + return (1); } if (srelen & 3) { - printf(", badlength=%u", srelen); - return; + ND_PRINT((ndo, ", badlength=%u", srelen)); + return (1); } if (sreoff >= srelen) { - printf(", badoff/len=%u/%u", sreoff, srelen); - return; + ND_PRINT((ndo, ", badoff/len=%u/%u", sreoff, srelen)); + return (1); } - for (;;) { - if (len < 4 || srelen == 0) - return; + while (srelen != 0) { + if (!ND_TTEST_4(bp)) + return (0); + if (len < 4) + return (0); - memcpy(&a, bp, sizeof(a)); - printf(" %s%s", - ((bp - up) == sreoff) ? "*" : "", - inet_ntoa(a)); + addrtostr(bp, buf, sizeof(buf)); + ND_PRINT((ndo, " %s%s", + ((bp - up) == sreoff) ? "*" : "", buf)); bp += 4; len -= 4; srelen -= 4; } + return (1); } -void -gre_sre_asn_print(u_int8_t sreoff, u_int8_t srelen, const u_char *bp, u_int len) +static int +gre_sre_asn_print(netdissect_options *ndo, uint8_t sreoff, uint8_t srelen, + const u_char *bp, u_int len) { const u_char *up = bp; if (sreoff & 1) { - printf(", badoffset=%u", sreoff); - return; + ND_PRINT((ndo, ", badoffset=%u", sreoff)); + return (1); } if (srelen & 1) { - printf(", badlength=%u", srelen); - return; + ND_PRINT((ndo, ", badlength=%u", srelen)); + return (1); } if (sreoff >= srelen) { - printf(", badoff/len=%u/%u", sreoff, srelen); - return; + ND_PRINT((ndo, ", badoff/len=%u/%u", sreoff, srelen)); + return (1); } - for (;;) { - if (len < 2 || srelen == 0) - return; + while (srelen != 0) { + if (!ND_TTEST_2(bp)) + return (0); + if (len < 2) + return (0); - printf(" %s%x", + ND_PRINT((ndo, " %s%x", ((bp - up) == sreoff) ? "*" : "", - EXTRACT_16BITS(bp)); + EXTRACT_BE_U_2(bp))); bp += 2; len -= 2; srelen -= 2; } + return (1); }