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 6460a59e0c471881f87d84af66ff8ffc6fb8fea2..6f35483bd42cb694714e1c0a08a08cbaf6fbd267 100644 (file)
--- 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;