X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/fb2479d733dbe8a991d11909b319341f7db62ab1..82cfcd4391f9f6c748634bfd7b48a44f42e6a53d:/print-nsh.c diff --git a/print-nsh.c b/print-nsh.c index 5ece5b5e..12a63cd6 100644 --- a/print-nsh.c +++ b/print-nsh.c @@ -23,7 +23,7 @@ /* \summary: Network Service Header (NSH) printer */ -/* specification: draft-ietf-sfc-nsh-01 */ +/* specification: RFC 8300 */ #ifdef HAVE_CONFIG_H #include @@ -31,131 +31,210 @@ #include "netdissect-stdinc.h" +#define ND_LONGJMP_FROM_TCHECK #include "netdissect.h" #include "extract.h" -static const char tstr[] = " [|NSH]"; static const struct tok nsh_flags [] = { - { 0x20, "O" }, - { 0x10, "C" }, + { 0x2, "O" }, { 0, NULL } }; +/* + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |Ver|O|U| TTL | Length |U|U|U|U|MD Type| Next Protocol | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ #define NSH_BASE_HDR_LEN 4 +#define NSH_VER(x) (((x) & 0xc0000000) >> 30) +#define NSH_FLAGS(x) (((x) & 0x30000000) >> 28) +#define NSH_TTL(x) (((x) & 0x0fc00000) >> 22) +#define NSH_LENGTH(x) (((x) & 0x003f0000) >> 16) +#define NSH_MD_TYPE(x) (((x) & 0x00000f00) >> 8) +#define NSH_NEXT_PROT(x) (((x) & 0x000000ff) >> 0) + #define NSH_SERVICE_PATH_HDR_LEN 4 #define NSH_HDR_WORD_SIZE 4U +#define MD_RSV 0x00 +#define MD_TYPE1 0x01 +#define MD_TYPE2 0x02 +#define MD_EXP 0x0F +static const struct tok md_str[] = { + { MD_RSV, "reserved" }, + { MD_TYPE1, "1" }, + { MD_TYPE2, "2" }, + { MD_EXP, "experimental" }, + { 0, NULL } +}; + +#define NP_IPV4 0x01 +#define NP_IPV6 0x02 +#define NP_ETH 0x03 +#define NP_NSH 0x04 +#define NP_MPLS 0x05 +#define NP_EXP1 0xFE +#define NP_EXP2 0xFF +static const struct tok np_str[] = { + { NP_IPV4, "IPv4" }, + { NP_IPV6, "IPv6" }, + { NP_ETH, "Ethernet" }, + { NP_NSH, "NSH" }, + { NP_MPLS, "MPLS" }, + { NP_EXP1, "Experiment 1" }, + { NP_EXP2, "Experiment 2" }, + { 0, NULL } +}; + void nsh_print(netdissect_options *ndo, const u_char *bp, u_int len) { - u_int n, vn; - uint8_t ver; - uint8_t flags; - u_int length; - uint8_t md_type; + uint32_t basehdr; + u_int ver, length, md_type; uint8_t next_protocol; - uint32_t service_path_id; - uint8_t service_index; - uint32_t ctx; - uint16_t tlv_class; - uint8_t tlv_type; - uint8_t tlv_len; + u_char past_headers = 0; u_int next_len; + ndo->ndo_protocol = "nsh"; + /* + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Base Header | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Service Path Header | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * ~ Context Header(s) ~ + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + /* print Base Header and Service Path Header */ - if (len < NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN) - goto trunc; + if (len < NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN) { + ND_PRINT(" (packet length %u < %u)", + len, NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN); + goto invalid; + } - ND_TCHECK_LEN(bp, NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN); - - ver = (uint8_t)(EXTRACT_U_1(bp) >> 6); - flags = EXTRACT_U_1(bp); - bp += 1; - length = EXTRACT_U_1(bp); - bp += 1; - md_type = EXTRACT_U_1(bp); - bp += 1; - next_protocol = EXTRACT_U_1(bp); - bp += 1; - service_path_id = EXTRACT_BE_U_3(bp); - bp += 3; - service_index = EXTRACT_U_1(bp); - bp += 1; + basehdr = GET_BE_U_4(bp); + bp += 4; + ver = NSH_VER(basehdr); + length = NSH_LENGTH(basehdr); + md_type = NSH_MD_TYPE(basehdr); + next_protocol = NSH_NEXT_PROT(basehdr); ND_PRINT("NSH, "); if (ndo->ndo_vflag > 1) { ND_PRINT("ver %u, ", ver); } - ND_PRINT("flags [%s], ", bittok2str_nosep(nsh_flags, "none", flags)); + if (ver != 0) + return; + ND_PRINT("flags [%s], ", + bittok2str_nosep(nsh_flags, "none", NSH_FLAGS(basehdr))); if (ndo->ndo_vflag > 2) { + ND_PRINT("TTL %u, ", NSH_TTL(basehdr)); ND_PRINT("length %u, ", length); - ND_PRINT("md type 0x%x, ", md_type); + ND_PRINT("md type %s, ", tok2str(md_str, "unknown (0x%02x)", md_type)); } if (ndo->ndo_vflag > 1) { - ND_PRINT("next-protocol 0x%x, ", next_protocol); + ND_PRINT("next-protocol %s, ", + tok2str(np_str, "unknown (0x%02x)", next_protocol)); } - ND_PRINT("service-path-id 0x%06x, ", service_path_id); - ND_PRINT("service-index 0x%x", service_index); /* Make sure we have all the headers */ - if (len < length * NSH_HDR_WORD_SIZE) - goto trunc; + if (len < length * NSH_HDR_WORD_SIZE) { + ND_PRINT(" (too many headers for packet length %u)", len); + goto invalid; + } - ND_TCHECK_LEN(bp, length * NSH_HDR_WORD_SIZE); + /* + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Service Path Identifier (SPI) | Service Index | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + */ + ND_PRINT("service-path-id 0x%06x, ", GET_BE_U_3(bp)); + bp += 3; + ND_PRINT("service-index 0x%x", GET_U_1(bp)); + bp += 1; /* * length includes the lengths of the Base and Service Path headers. * That means it must be at least 2. */ - if (length < 2) - goto trunc; + if (length < 2) { + ND_PRINT(" (less than two headers)"); + goto invalid; + } /* * Print, or skip, the Context Headers. * (length - 2) is the length of those headers. */ if (ndo->ndo_vflag > 2) { - if (md_type == 0x01) { + u_int n; + + if (md_type == MD_TYPE1) { + if (length != 6) { + ND_PRINT(" (invalid length for the MD type)"); + goto invalid; + } for (n = 0; n < length - 2; n++) { - ctx = EXTRACT_BE_U_4(bp); + ND_PRINT("\n Context[%02u]: 0x%08x", n, GET_BE_U_4(bp)); bp += NSH_HDR_WORD_SIZE; - ND_PRINT("\n Context[%02u]: 0x%08x", n, ctx); } + past_headers = 1; } - else if (md_type == 0x02) { + else if (md_type == MD_TYPE2) { n = 0; while (n < length - 2) { - tlv_class = EXTRACT_BE_U_2(bp); + uint16_t tlv_class; + uint8_t tlv_type, tlv_len, tlv_len_padded; + + tlv_class = GET_BE_U_2(bp); bp += 2; - tlv_type = EXTRACT_U_1(bp); + tlv_type = GET_U_1(bp); bp += 1; - tlv_len = EXTRACT_U_1(bp); + tlv_len = GET_U_1(bp) & 0x7f; bp += 1; + tlv_len_padded = roundup2(tlv_len, NSH_HDR_WORD_SIZE); ND_PRINT("\n TLV Class %u, Type %u, Len %u", tlv_class, tlv_type, tlv_len); n += 1; - if (length - 2 < n + tlv_len) { - ND_PRINT(" ERROR: invalid-tlv-length"); - return; + if (length - 2 < n + tlv_len_padded / NSH_HDR_WORD_SIZE) { + ND_PRINT(" (length too big)"); + goto invalid; } - for (vn = 0; vn < tlv_len; vn++) { - ctx = EXTRACT_BE_U_4(bp); - bp += NSH_HDR_WORD_SIZE; - ND_PRINT("\n Value[%02u]: 0x%08x", vn, ctx); + if (tlv_len) { + const char *sep = "0x"; + u_int vn; + + ND_PRINT("\n Value: "); + for (vn = 0; vn < tlv_len; vn++) { + ND_PRINT("%s%02x", sep, GET_U_1(bp)); + bp += 1; + sep = ":"; + } + /* Cover any TLV padding. */ + ND_TCHECK_LEN(bp, tlv_len_padded - tlv_len); + bp += tlv_len_padded - tlv_len; + n += tlv_len_padded / NSH_HDR_WORD_SIZE; } - n += tlv_len; } - } - else { - ND_PRINT("ERROR: unknown-next-protocol"); - return; + past_headers = 1; } } - else { + if (! past_headers) { + ND_TCHECK_LEN(bp, (length - 2) * NSH_HDR_WORD_SIZE); bp += (length - 2) * NSH_HDR_WORD_SIZE; } ND_PRINT(ndo->ndo_vflag ? "\n " : ": "); @@ -163,14 +242,14 @@ nsh_print(netdissect_options *ndo, const u_char *bp, u_int len) /* print Next Protocol */ next_len = len - length * NSH_HDR_WORD_SIZE; switch (next_protocol) { - case 0x1: + case NP_IPV4: ip_print(ndo, bp, next_len); break; - case 0x2: + case NP_IPV6: ip6_print(ndo, bp, next_len); break; - case 0x3: - ether_print(ndo, bp, next_len, ndo->ndo_snapend - bp, NULL, NULL); + case NP_ETH: + ether_print(ndo, bp, next_len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL); break; default: ND_PRINT("ERROR: unknown-next-protocol"); @@ -179,7 +258,7 @@ nsh_print(netdissect_options *ndo, const u_char *bp, u_int len) return; -trunc: - ND_PRINT("%s", tstr); +invalid: + nd_print_invalid(ndo); }