X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/99f6d01b24d037f4d69ad098f085d98e3d1b73b4..3d1bade63b45bc1a0fc0ea49949e0d165b2383b0:/print-ether.c diff --git a/print-ether.c b/print-ether.c index 57c07ce9..ba488343 100644 --- a/print-ether.c +++ b/print-ether.c @@ -22,16 +22,31 @@ /* \summary: Ethernet printer */ #ifdef HAVE_CONFIG_H -#include "config.h" +#include #endif -#include +#include "netdissect-stdinc.h" #include "netdissect.h" #include "extract.h" #include "addrtoname.h" #include "ethertype.h" -#include "ether.h" + +/* + * Structure of an Ethernet header. + */ +struct ether_header { + nd_mac_addr ether_dhost; + nd_mac_addr ether_shost; + nd_uint16_t ether_length_type; +}; + +/* + * Length of an Ethernet header; note that some compilers may pad + * "struct ether_header" to a multiple of 4 bytes, for example, so + * "sizeof (struct ether_header)" may not give the right answer. + */ +#define ETHER_HDRLEN 14 const struct tok ethertype_values[] = { { ETHERTYPE_IP, "IPv4" }, @@ -89,41 +104,44 @@ const struct tok ethertype_values[] = { { 0, NULL} }; -static inline void +static void ether_hdr_print(netdissect_options *ndo, - const u_char *bp, u_int length) + const u_char *bp, u_int length, + u_int hdrlen) { - register const struct ether_header *ep; + const struct ether_header *ehp; uint16_t length_type; - ep = (const struct ether_header *)bp; + ehp = (const struct ether_header *)bp; - ND_PRINT((ndo, "%s > %s", - etheraddr_string(ndo, ESRC(ep)), - etheraddr_string(ndo, EDST(ep)))); + ND_PRINT("%s > %s", + etheraddr_string(ndo, ehp->ether_shost), + etheraddr_string(ndo, ehp->ether_dhost)); - length_type = EXTRACT_16BITS(&ep->ether_length_type); + length_type = EXTRACT_BE_U_2(bp + + (hdrlen - sizeof(ehp->ether_length_type))); if (!ndo->ndo_qflag) { - if (length_type <= ETHERMTU) { - ND_PRINT((ndo, ", 802.3")); + if (length_type <= MAX_ETHERNET_LENGTH_VAL) { + ND_PRINT(", 802.3"); length = length_type; } else - ND_PRINT((ndo, ", ethertype %s (0x%04x)", + ND_PRINT(", ethertype %s (0x%04x)", tok2str(ethertype_values,"Unknown", length_type), - length_type)); + length_type); } else { - if (length_type <= ETHERMTU) { - ND_PRINT((ndo, ", 802.3")); + if (length_type <= MAX_ETHERNET_LENGTH_VAL) { + ND_PRINT(", 802.3"); length = length_type; } else - ND_PRINT((ndo, ", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", length_type))); + ND_PRINT(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", length_type)); } - ND_PRINT((ndo, ", length %u: ", length)); + ND_PRINT(", length %u: ", length); } /* - * Print an Ethernet frame. + * Print an Ethernet frame while specyfing a non-standard Ethernet header + * length. * This might be encapsulated within another frame; we might be passed * a pointer to a function that can print header information for that * frame's protocol, and an argument to pass to that function. @@ -131,50 +149,58 @@ ether_hdr_print(netdissect_options *ndo, * FIXME: caplen can and should be derived from ndo->ndo_snapend and p. */ u_int -ether_print(netdissect_options *ndo, +ether_print_hdr_len(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen, - void (*print_encap_header)(netdissect_options *ndo, const u_char *), const u_char *encap_header_arg) + void (*print_encap_header)(netdissect_options *ndo, const u_char *), + const u_char *encap_header_arg, u_int hdrlen) { - const struct ether_header *ep; + const struct ether_header *ehp; u_int orig_length; u_short length_type; - u_int hdrlen; int llc_hdrlen; struct lladdr_info src, dst; - if (caplen < ETHER_HDRLEN) { - ND_PRINT((ndo, "[|ether]")); + /* Unless specified otherwise, assume a standard Ethernet header */ + if (hdrlen == ETHER_HDRLEN) + ndo->ndo_protocol = "ether"; + + if (caplen < hdrlen) { + nd_print_trunc(ndo); return (caplen); } - if (length < ETHER_HDRLEN) { - ND_PRINT((ndo, "[|ether]")); + if (length < hdrlen) { + nd_print_trunc(ndo); return (length); } + /* If the offset is set, then the upper printer is responsible for + * printing the relevant part of the Ethernet header. + */ if (ndo->ndo_eflag) { if (print_encap_header != NULL) (*print_encap_header)(ndo, encap_header_arg); - ether_hdr_print(ndo, p, length); + ether_hdr_print(ndo, p, length, hdrlen); } + orig_length = length; - length -= ETHER_HDRLEN; - caplen -= ETHER_HDRLEN; - ep = (const struct ether_header *)p; - p += ETHER_HDRLEN; - hdrlen = ETHER_HDRLEN; + length -= hdrlen; + caplen -= hdrlen; + ehp = (const struct ether_header *)p; + p += hdrlen; - src.addr = ESRC(ep); + src.addr = ehp->ether_shost; src.addr_string = etheraddr_string; - dst.addr = EDST(ep); + dst.addr = ehp->ether_dhost; dst.addr_string = etheraddr_string; - length_type = EXTRACT_16BITS(&ep->ether_length_type); + length_type = EXTRACT_BE_U_2((const u_char *)ehp + + (hdrlen - sizeof(ehp->ether_length_type))); recurse: /* * Is it (gag) an 802.3 encapsulation? */ - if (length_type <= ETHERMTU) { + if (length_type <= MAX_ETHERNET_LENGTH_VAL) { /* Try to print the LLC-layer header & higher layers */ llc_hdrlen = llc_print(ndo, p, length, caplen, &src, &dst); if (llc_hdrlen < 0) { @@ -193,22 +219,24 @@ recurse: * the enclosed type field. */ if (caplen < 4) { - ND_PRINT((ndo, "[|vlan]")); + ndo->ndo_protocol = "vlan"; + nd_print_trunc(ndo); return (hdrlen + caplen); } if (length < 4) { - ND_PRINT((ndo, "[|vlan]")); + ndo->ndo_protocol = "vlan"; + nd_print_trunc(ndo); return (hdrlen + length); } if (ndo->ndo_eflag) { - uint16_t tag = EXTRACT_16BITS(p); + uint16_t tag = EXTRACT_BE_U_2(p); - ND_PRINT((ndo, "%s, ", ieee8021q_tci_string(tag))); + ND_PRINT("%s, ", ieee8021q_tci_string(tag)); } - length_type = EXTRACT_16BITS(p + 2); - if (ndo->ndo_eflag && length_type > ETHERMTU) - ND_PRINT((ndo, "ethertype %s, ", tok2str(ethertype_values,"0x%04x", length_type))); + length_type = EXTRACT_BE_U_2(p + 2); + if (ndo->ndo_eflag && length_type > MAX_ETHERNET_LENGTH_VAL) + ND_PRINT("ethertype %s, ", tok2str(ethertype_values,"0x%04x", length_type)); p += 4; length -= 4; caplen -= 4; @@ -239,7 +267,8 @@ recurse: if (!ndo->ndo_eflag) { if (print_encap_header != NULL) (*print_encap_header)(ndo, encap_header_arg); - ether_hdr_print(ndo, (const u_char *)ep, orig_length); + ether_hdr_print(ndo, (const u_char *)ehp, orig_length, + hdrlen); } if (!ndo->ndo_suppress_default_print) @@ -249,6 +278,25 @@ recurse: return (hdrlen); } +/* + * Print an Ethernet frame. + * This might be encapsulated within another frame; we might be passed + * a pointer to a function that can print header information for that + * frame's protocol, and an argument to pass to that function. + * + * FIXME: caplen can and should be derived from ndo->ndo_snapend and p. + */ +u_int +ether_print(netdissect_options *ndo, + const u_char *p, u_int length, u_int caplen, + void (*print_encap_header)(netdissect_options *ndo, const u_char *), + const u_char *encap_header_arg) +{ + return (ether_print_hdr_len(ndo, p, length, caplen, + print_encap_header, encap_header_arg, + ETHER_HDRLEN)); +} + /* * This is the top level routine of the printer. 'p' points * to the ether header of the packet, 'h->len' is the length @@ -259,6 +307,7 @@ u_int ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) { + ndo->ndo_protocol = "ether_if"; return (ether_print(ndo, p, h->len, h->caplen, NULL, NULL)); } @@ -278,8 +327,9 @@ netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, /* * Fail if we don't have enough data for the Hilscher pseudo-header. */ - if (h->len < 4 || h->caplen < 4) { - ND_PRINT((ndo, "[|netanalyzer]")); + ndo->ndo_protocol = "netanalyzer_if"; + if (h->caplen < 4) { + nd_print_trunc(ndo); return (h->caplen); } @@ -306,8 +356,9 @@ netanalyzer_transparent_if_print(netdissect_options *ndo, * Fail if we don't have enough data for the Hilscher pseudo-header, * preamble, and SOF. */ - if (h->len < 12 || h->caplen < 12) { - ND_PRINT((ndo, "[|netanalyzer-transparent]")); + ndo->ndo_protocol = "netanalyzer_transparent_if"; + if (h->caplen < 12) { + nd_print_trunc(ndo); return (h->caplen); } @@ -349,7 +400,7 @@ ethertype_print(netdissect_options *ndo, case ETHERTYPE_ATALK: if (ndo->ndo_vflag) - ND_PRINT((ndo, "et1 ")); + ND_PRINT("et1 "); atalk_print(ndo, p, length); return (1); @@ -358,16 +409,17 @@ ethertype_print(netdissect_options *ndo, return (1); case ETHERTYPE_IPX: - ND_PRINT((ndo, "(NOV-ETHII) ")); + ND_PRINT("(NOV-ETHII) "); ipx_print(ndo, p, length); return (1); case ETHERTYPE_ISO: if (length == 0 || caplen == 0) { - ND_PRINT((ndo, " [|osi]")); + ndo->ndo_protocol = "isoclns"; + nd_print_trunc(ndo); return (1); } - isoclns_print(ndo, p + 1, length - 1, caplen - 1); + isoclns_print(ndo, p + 1, length - 1); return(1); case ETHERTYPE_PPPOED: @@ -387,7 +439,7 @@ ethertype_print(netdissect_options *ndo, case ETHERTYPE_PPP: if (length) { - ND_PRINT((ndo, ": ")); + ND_PRINT(": "); ppp_print(ndo, p, length); } return (1); @@ -457,12 +509,3 @@ ethertype_print(netdissect_options *ndo, return (0); } } - - -/* - * Local Variables: - * c-style: whitesmith - * c-basic-offset: 8 - * End: - */ -