From: Guy Harris Date: Sat, 3 Mar 2012 01:30:32 +0000 (-0800) Subject: Fix printing of BGP optional headers. X-Git-Tag: tcpdump-4.3.0~26 X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/7e4eb0a86ca6eee9911caa3dac333309b1bd3d5b?ds=inline Fix printing of BGP optional headers. Anonymously contributed patch; tested with Cisco and Arista routers by the patch contributor. --- diff --git a/print-bgp.c b/print-bgp.c index 6460a59e..6f35483b 100644 --- a/print-bgp.c +++ b/print-bgp.c @@ -93,6 +93,7 @@ struct bgp_opt { /* variable length */ }; #define BGP_OPT_SIZE 2 /* some compilers may pad to 4 bytes */ +#define BGP_CAP_HEADER_SIZE 2 /* some compilers may pad to 4 bytes */ #define BGP_UPDATE_MINSIZE 23 @@ -2155,15 +2156,98 @@ trunc: return 0; } +static void +bgp_capabilities_print(const u_char *opt, int caps_len) +{ + char tokbuf[TOKBUFSIZE]; + char tokbuf2[TOKBUFSIZE]; + int cap_type, cap_len, tcap_len, cap_offset; + int i = 0; + + while (i < caps_len) { + TCHECK2(opt[i], BGP_CAP_HEADER_SIZE); + cap_type=opt[i]; + cap_len=opt[i+1]; + tcap_len=cap_len; + printf("\n\t %s (%u), length: %u", + tok2strbuf(bgp_capcode_values, "Unknown", + cap_type, tokbuf, sizeof(tokbuf)), + cap_type, + cap_len); + TCHECK2(opt[i+2], cap_len); + switch (cap_type) { + case BGP_CAPCODE_MP: + printf("\n\t\tAFI %s (%u), SAFI %s (%u)", + tok2strbuf(af_values, "Unknown", + EXTRACT_16BITS(opt+i+2), + tokbuf, sizeof(tokbuf)), + EXTRACT_16BITS(opt+i+2), + tok2strbuf(bgp_safi_values, "Unknown", + opt[i+5], + tokbuf, sizeof(tokbuf)), + opt[i+5]); + break; + case BGP_CAPCODE_RESTART: + printf("\n\t\tRestart Flags: [%s], Restart Time %us", + ((opt[i+2])&0x80) ? "R" : "none", + EXTRACT_16BITS(opt+i+2)&0xfff); + tcap_len-=2; + cap_offset=4; + while(tcap_len>=4) { + printf("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s", + tok2strbuf(af_values,"Unknown", + EXTRACT_16BITS(opt+i+cap_offset), + tokbuf, sizeof(tokbuf)), + EXTRACT_16BITS(opt+i+cap_offset), + tok2strbuf(bgp_safi_values,"Unknown", + opt[i+cap_offset+2], + tokbuf2, sizeof(tokbuf2)), + opt[i+cap_offset+2], + ((opt[i+cap_offset+3])&0x80) ? "yes" : "no" ); + tcap_len-=4; + cap_offset+=4; + } + break; + case BGP_CAPCODE_RR: + case BGP_CAPCODE_RR_CISCO: + break; + case BGP_CAPCODE_AS_NEW: + + /* + * Extract the 4 byte AS number encoded. + */ + if (cap_len == 4) { + printf("\n\t\t 4 Byte AS %s", + as_printf(astostr, sizeof(astostr), + EXTRACT_32BITS(opt + i + 2))); + } + break; + default: + printf("\n\t\tno decoder for Capability %u", + cap_type); + if (vflag <= 1) + print_unknown_data(&opt[i+2],"\n\t\t",cap_len); + break; + } + if (vflag > 1 && cap_len > 0) { + print_unknown_data(&opt[i+2],"\n\t\t",cap_len); + } + i += BGP_CAP_HEADER_SIZE + cap_len; + } + return; + +trunc: + printf("[|BGP]"); +} + static void bgp_open_print(const u_char *dat, int length) { struct bgp_open bgpo; struct bgp_opt bgpopt; const u_char *opt; - int i,cap_type,cap_len,tcap_len,cap_offset; + int i; char tokbuf[TOKBUFSIZE]; - char tokbuf2[TOKBUFSIZE]; TCHECK2(dat[0], BGP_OPEN_SIZE); memcpy(&bgpo, dat, BGP_OPEN_SIZE); @@ -2188,96 +2272,31 @@ bgp_open_print(const u_char *dat, int length) TCHECK2(opt[i], BGP_OPT_SIZE); memcpy(&bgpopt, &opt[i], BGP_OPT_SIZE); if (i + 2 + bgpopt.bgpopt_len > bgpo.bgpo_optlen) { - printf("\n\t Option %d, length: %u", bgpopt.bgpopt_type, bgpopt.bgpopt_len); + printf("\n\t Option %d, length: %u", bgpopt.bgpopt_type, bgpopt.bgpopt_len); break; } printf("\n\t Option %s (%u), length: %u", - tok2strbuf(bgp_opt_values,"Unknown", + tok2strbuf(bgp_opt_values,"Unknown", bgpopt.bgpopt_type, tokbuf, sizeof(tokbuf)), - bgpopt.bgpopt_type, - bgpopt.bgpopt_len); - - /* now lets decode the options we know*/ - switch(bgpopt.bgpopt_type) { - case BGP_OPT_CAP: - cap_type=opt[i+BGP_OPT_SIZE]; - cap_len=opt[i+BGP_OPT_SIZE+1]; - tcap_len=cap_len; - printf("\n\t %s (%u), length: %u", - tok2strbuf(bgp_capcode_values, "Unknown", - cap_type, tokbuf, sizeof(tokbuf)), - cap_type, - cap_len); - switch(cap_type) { - case BGP_CAPCODE_MP: - printf("\n\t\tAFI %s (%u), SAFI %s (%u)", - tok2strbuf(af_values, "Unknown", - EXTRACT_16BITS(opt+i+BGP_OPT_SIZE+2), - tokbuf, sizeof(tokbuf)), - EXTRACT_16BITS(opt+i+BGP_OPT_SIZE+2), - tok2strbuf(bgp_safi_values, "Unknown", - opt[i+BGP_OPT_SIZE+5], - tokbuf, sizeof(tokbuf)), - opt[i+BGP_OPT_SIZE+5]); - break; - case BGP_CAPCODE_RESTART: - printf("\n\t\tRestart Flags: [%s], Restart Time %us", - ((opt[i+BGP_OPT_SIZE+2])&0x80) ? "R" : "none", - EXTRACT_16BITS(opt+i+BGP_OPT_SIZE+2)&0xfff); - tcap_len-=2; - cap_offset=4; - while(tcap_len>=4) { - printf("\n\t\t AFI %s (%u), SAFI %s (%u), Forwarding state preserved: %s", - tok2strbuf(af_values,"Unknown", - EXTRACT_16BITS(opt+i+BGP_OPT_SIZE+cap_offset), - tokbuf, sizeof(tokbuf)), - EXTRACT_16BITS(opt+i+BGP_OPT_SIZE+cap_offset), - tok2strbuf(bgp_safi_values,"Unknown", - opt[i+BGP_OPT_SIZE+cap_offset+2], - tokbuf2, sizeof(tokbuf2)), - opt[i+BGP_OPT_SIZE+cap_offset+2], - ((opt[i+BGP_OPT_SIZE+cap_offset+3])&0x80) ? "yes" : "no" ); - tcap_len-=4; - cap_offset+=4; - } - break; - case BGP_CAPCODE_RR: - case BGP_CAPCODE_RR_CISCO: - break; - case BGP_CAPCODE_AS_NEW: - - /* - * Extract the 4 byte AS number encoded. - */ - TCHECK2(opt[i + BGP_OPT_SIZE + 2], cap_len); - if (cap_len == 4) { - printf("\n\t\t 4 Byte AS %s", - as_printf(astostr, sizeof(astostr), - EXTRACT_32BITS(opt + i + BGP_OPT_SIZE + 2))); - } - break; - default: - TCHECK2(opt[i+BGP_OPT_SIZE+2],cap_len); - printf("\n\t\tno decoder for Capability %u", - cap_type); - if (vflag <= 1) - print_unknown_data(&opt[i+BGP_OPT_SIZE+2],"\n\t\t",cap_len); - break; - } - if (vflag > 1) { - TCHECK2(opt[i+BGP_OPT_SIZE+2],cap_len); - print_unknown_data(&opt[i+BGP_OPT_SIZE+2],"\n\t\t",cap_len); - } - break; - case BGP_OPT_AUTH: - default: - printf("\n\t no decoder for option %u", - bgpopt.bgpopt_type); - break; - } + bgpopt.bgpopt_type, + bgpopt.bgpopt_len); + /* now let's decode the options we know*/ + switch(bgpopt.bgpopt_type) { + + case BGP_OPT_CAP: + bgp_capabilities_print(&opt[i+BGP_OPT_SIZE], + bgpopt.bgpopt_len); + break; + + case BGP_OPT_AUTH: + default: + printf("\n\t no decoder for option %u", + bgpopt.bgpopt_type); + break; + } i += BGP_OPT_SIZE + bgpopt.bgpopt_len; } return;