/* * Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior * written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ /* \summary: Compressed Serial Line Internet Protocol printer */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "netdissect.h" #include "extract.h" #include "ip.h" #include "tcp.h" #include "slcompress.h" /* * definitions of the pseudo- link-level header attached to slip * packets grabbed by the packet filter (bpf) traffic monitor. */ #define SLIP_HDRLEN 16 #define SLX_DIR 0 #define SLX_CHDR 1 #define CHDR_LEN 15 #define SLIPDIR_IN 0 #define SLIPDIR_OUT 1 static const char tstr[] = "[|slip]"; static u_int lastlen[2][256]; static u_int lastconn = 255; static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int); static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int); u_int sl_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) { register u_int caplen = h->caplen; register u_int length = h->len; register const struct ip *ip; if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) { ND_PRINT((ndo, "%s", tstr)); return (caplen); } caplen -= SLIP_HDRLEN; length -= SLIP_HDRLEN; ip = (const struct ip *)(p + SLIP_HDRLEN); if (ndo->ndo_eflag) sliplink_print(ndo, p, ip, length); if (caplen < 1 || length < 1) { ND_PRINT((ndo, "%s", tstr)); return (caplen + SLIP_HDRLEN); } switch (IP_V(ip)) { case 4: ip_print(ndo, (const u_char *)ip, length); break; case 6: ip6_print(ndo, (const u_char *)ip, length); break; default: ND_PRINT((ndo, "ip v%d", IP_V(ip))); } return (SLIP_HDRLEN); } u_int sl_bsdos_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p) { register u_int caplen = h->caplen; register u_int length = h->len; register const struct ip *ip; if (caplen < SLIP_HDRLEN) { ND_PRINT((ndo, "%s", tstr)); return (caplen); } length -= SLIP_HDRLEN; ip = (const struct ip *)(p + SLIP_HDRLEN); #ifdef notdef if (ndo->ndo_eflag) sliplink_print(ndo, p, ip, length); #endif ip_print(ndo, (const u_char *)ip, length); return (SLIP_HDRLEN); } static void sliplink_print(netdissect_options *ndo, register const u_char *p, register const struct ip *ip, register u_int length) { int dir; u_int hlen; dir = p[SLX_DIR]; ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O ")); if (ndo->ndo_nflag) { /* XXX just dump the header */ register int i; for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i) ND_PRINT((ndo, "%02x.", p[i])); ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1])); return; } switch (p[SLX_CHDR] & 0xf0) { case TYPE_IP: ND_PRINT((ndo, "ip %d: ", length + SLIP_HDRLEN)); break; case TYPE_UNCOMPRESSED_TCP: /* * The connection id is stored in the IP protocol field. * Get it from the link layer since sl_uncompress_tcp() * has restored the IP header copy to IPPROTO_TCP. */ lastconn = ((const struct ip *)&p[SLX_CHDR])->ip_p; hlen = IP_HL(ip); hlen += TH_OFF((const struct tcphdr *)&((const int *)ip)[hlen]); lastlen[dir][lastconn] = length - (hlen << 2); ND_PRINT((ndo, "utcp %d: ", lastconn)); break; default: if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) { compressed_sl_print(ndo, &p[SLX_CHDR], ip, length, dir); ND_PRINT((ndo, ": ")); } else ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR])); } } static const u_char * print_sl_change(netdissect_options *ndo, const char *str, register const u_char *cp) { register u_int i; if ((i = *cp++) == 0) { i = EXTRACT_16BITS(cp); cp += 2; } ND_PRINT((ndo, " %s%d", str, i)); return (cp); } static const u_char * print_sl_winchange(netdissect_options *ndo, register const u_char *cp) { register short i; if ((i = *cp++) == 0) { i = EXTRACT_16BITS(cp); cp += 2; } if (i >= 0) ND_PRINT((ndo, " W+%d", i)); else ND_PRINT((ndo, " W%d", i)); return (cp); } static void compressed_sl_print(netdissect_options *ndo, const u_char *chdr, const struct ip *ip, u_int length, int dir) { register const u_char *cp = chdr; register u_int flags, hlen; flags = *cp++; if (flags & NEW_C) { lastconn = *cp++; ND_PRINT((ndo, "ctcp %d", lastconn)); } else ND_PRINT((ndo, "ctcp *")); /* skip tcp checksum */ cp += 2; switch (flags & SPECIALS_MASK) { case SPECIAL_I: ND_PRINT((ndo, " *SA+%d", lastlen[dir][lastconn])); break; case SPECIAL_D: ND_PRINT((ndo, " *S+%d", lastlen[dir][lastconn])); break; default: if (flags & NEW_U) cp = print_sl_change(ndo, "U=", cp); if (flags & NEW_W) cp = print_sl_winchange(ndo, cp); if (flags & NEW_A) cp = print_sl_change(ndo, "A+", cp); if (flags & NEW_S) cp = print_sl_change(ndo, "S+", cp); break; } if (flags & NEW_I) cp = print_sl_change(ndo, "I+", cp); /* * 'hlen' is the length of the uncompressed TCP/IP header (in words). * 'cp - chdr' is the length of the compressed header. * 'length - hlen' is the amount of data in the packet. */ hlen = IP_HL(ip); hlen += TH_OFF((const struct tcphdr *)&((const int32_t *)ip)[hlen]); lastlen[dir][lastconn] = length - (hlen << 2); ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr))); }