X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/4c76b828529c59ccb0eaf3d67e594f298b26900c..233f4c20af017634d373bd3cdbd5b1139469ced6:/print-null.c diff --git a/print-null.c b/print-null.c index a4b4085e..74c67bf9 100644 --- a/print-null.c +++ b/print-null.c @@ -20,24 +20,15 @@ */ #ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.39 2000-12-04 06:47:17 guy Exp $ (LBL)"; +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.49.2.2 2003-11-16 08:51:36 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif -#include -#include -#include -#include -#include - -struct mbuf; -struct rtentry; - -#include +#include #include #include @@ -51,90 +42,158 @@ struct rtentry; #include "ip6.h" #endif -#ifndef AF_NS -#define AF_NS 6 /* XEROX NS protocols */ -#endif - /* - * The DLT_NULL packet header is 4 bytes long. It contains a network - * order 32 bit integer that specifies the family, e.g. AF_INET + * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order + * 32-bit integer that specifies the family, e.g. AF_INET. + * + * Note here that "host" refers to the host on which the packets were + * captured; that isn't necessarily *this* host. + * + * The OpenBSD DLT_LOOP packet header is the same, except that the integer + * is in network byte order. */ #define NULL_HDRLEN 4 +/* + * BSD AF_ values. + * + * Unfortunately, the BSDs don't all use the same value for AF_INET6, + * so, because we want to be able to read captures from all of the BSDs, + * we check for all of them. + */ +#define BSD_AF_INET 2 +#define BSD_AF_NS 6 /* XEROX NS protocols */ +#define BSD_AF_ISO 7 +#define BSD_AF_APPLETALK 16 +#define BSD_AF_IPX 23 +#define BSD_AF_INET6_BSD 24 /* OpenBSD (and probably NetBSD), BSD/OS */ +#define BSD_AF_INET6_FREEBSD 28 +#define BSD_AF_INET6_DARWIN 30 + static void -null_print(const u_char *p, const struct ip *ip, u_int length) +null_print(u_int family, u_int length) { - u_int family; - - memcpy((char *)&family, (char *)p, sizeof(family)); - if (nflag) - printf("AF %d ", family); + printf("AF %u ", family); else { switch (family) { - case AF_INET: + case BSD_AF_INET: printf("ip "); break; #ifdef INET6 - case AF_INET6: + case BSD_AF_INET6_BSD: + case BSD_AF_INET6_FREEBSD: + case BSD_AF_INET6_DARWIN: printf("ip6 "); break; #endif - case AF_NS: + case BSD_AF_NS: printf("ns "); break; + case BSD_AF_ISO: + printf("osi "); + break; + + case BSD_AF_APPLETALK: + printf("atalk "); + break; + + case BSD_AF_IPX: + printf("ipx "); + break; + default: - printf("AF %d ", family); + printf("AF %u ", family); break; } } printf("%d: ", length); } -void -null_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p) +/* + * Byte-swap a 32-bit number. + * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on + * big-endian platforms.) + */ +#define SWAPLONG(y) \ +((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff)) + +/* + * This is the top level routine of the printer. 'p' points + * to the ether header of the packet, 'h->ts' is the timestamp, + * 'h->length' is the length of the packet off the wire, and 'h->caplen' + * is the number of bytes actually captured. + */ +u_int +null_if_print(const struct pcap_pkthdr *h, const u_char *p) { u_int length = h->len; u_int caplen = h->caplen; - const struct ip *ip; + u_int family; - ts_print(&h->ts); + if (caplen < NULL_HDRLEN) { + printf("[|null]"); + return (NULL_HDRLEN); + } + + memcpy((char *)&family, (char *)p, sizeof(family)); /* - * Some printers want to get back at the link level addresses, - * and/or check that they're not walking off the end of the packet. - * Rather than pass them all the way down, we set these globals. + * This isn't necessarily in our host byte order; if this is + * a DLT_LOOP capture, it's in network byte order, and if + * this is a DLT_NULL capture from a machine with the opposite + * byte-order, it's in the opposite byte order from ours. + * + * If the upper 16 bits aren't all zero, assume it's byte-swapped. */ - packetp = p; - snapend = p + caplen; + if ((family & 0xFFFF0000) != 0) + family = SWAPLONG(family); length -= NULL_HDRLEN; - - ip = (struct ip *)(p + NULL_HDRLEN); + caplen -= NULL_HDRLEN; + p += NULL_HDRLEN; if (eflag) - null_print(p, ip, length); + null_print(family, length); + + switch (family) { - switch (IP_V(ip)) { - case 4: - ip_print((const u_char *)ip, length); + case BSD_AF_INET: + ip_print(p, length); break; + #ifdef INET6 - case 6: - ip6_print((const u_char *)ip, length); + case BSD_AF_INET6_BSD: + case BSD_AF_INET6_FREEBSD: + case BSD_AF_INET6_DARWIN: + ip6_print(p, length); break; -#endif /* INET6 */ - default: - printf("ip v%d", IP_V(ip)); +#endif + + case BSD_AF_ISO: + isoclns_print(p, length, caplen); + break; + + case BSD_AF_APPLETALK: + atalk_print(p, length); + break; + + case BSD_AF_IPX: + ipx_print(p, length); break; + + default: + /* unknown AF_ value */ + if (!eflag) + null_print(family, length + NULL_HDRLEN); + if (!xflag && !qflag) + default_print(p, caplen); } - if (xflag) - default_print((const u_char *)ip, caplen - NULL_HDRLEN); - putchar('\n'); + return (NULL_HDRLEN); }