/* * Copyright (c) 2007-2011 Grégoire Henry, Juliusz Chroboczek * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project 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 BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include "netdissect.h" #include "addrtoname.h" #include "extract.h" static const char tstr[] = "[|babel]"; static const char istr[] = " (invalid)"; static void babel_print_v2(netdissect_options *, const u_char *cp, u_int length); void babel_print(netdissect_options *ndo, const u_char *cp, u_int length) { ND_PRINT((ndo, "babel")); ND_TCHECK2(*cp, 4); if(cp[0] != 42) { ND_PRINT((ndo, " invalid header")); return; } else { ND_PRINT((ndo, " %d", cp[1])); } switch(cp[1]) { case 2: babel_print_v2(ndo, cp, length); break; default: ND_PRINT((ndo, " unknown version")); break; } return; trunc: ND_PRINT((ndo, " %s", tstr)); return; } /* TLVs */ #define MESSAGE_PAD1 0 #define MESSAGE_PADN 1 #define MESSAGE_ACK_REQ 2 #define MESSAGE_ACK 3 #define MESSAGE_HELLO 4 #define MESSAGE_IHU 5 #define MESSAGE_ROUTER_ID 6 #define MESSAGE_NH 7 #define MESSAGE_UPDATE 8 #define MESSAGE_REQUEST 9 #define MESSAGE_MH_REQUEST 10 #define MESSAGE_TSPC 11 #define MESSAGE_HMAC 12 #define MESSAGE_UPDATE_SRC_SPECIFIC 13 #define MESSAGE_REQUEST_SRC_SPECIFIC 14 #define MESSAGE_MH_REQUEST_SRC_SPECIFIC 15 /* sub-TLVs */ #define MESSAGE_SUB_PAD1 0 #define MESSAGE_SUB_PADN 1 #define MESSAGE_SUB_DIVERSITY 2 #define MESSAGE_SUB_TIMESTAMP 3 /* Diversity sub-TLV channel codes */ static const struct tok diversity_str[] = { { 0, "reserved" }, { 255, "all" }, { 0, NULL } }; static const char * format_id(const u_char *id) { static char buf[25]; snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x", id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]); buf[24] = '\0'; return buf; } static const unsigned char v4prefix[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 }; static const char * format_prefix(netdissect_options *ndo, const u_char *prefix, unsigned char plen) { static char buf[50]; if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0) snprintf(buf, 50, "%s/%u", ipaddr_string(ndo, prefix + 12), plen - 96); else #ifdef INET6 snprintf(buf, 50, "%s/%u", ip6addr_string(ndo, prefix), plen); #else snprintf(buf, 50, "IPv6 addresses not supported"); #endif buf[49] = '\0'; return buf; } static const char * format_address(netdissect_options *ndo, const u_char *prefix) { if(memcmp(prefix, v4prefix, 12) == 0) return ipaddr_string(ndo, prefix + 12); else #ifdef INET6 return ip6addr_string(ndo, prefix); #else return "IPv6 addresses not supported"; #endif } static const char * format_interval(const uint16_t i) { static char buf[sizeof("000.00s")]; if (i == 0) return "0.0s (bogus)"; snprintf(buf, sizeof(buf), "%u.%02us", i / 100, i % 100); return buf; } static const char * format_interval_update(const uint16_t i) { return i == 0xFFFF ? "infinity" : format_interval(i); } static const char * format_timestamp(const uint32_t i) { static char buf[sizeof("0000.000000s")]; snprintf(buf, sizeof(buf), "%u.%06us", i / 1000000, i % 1000000); return buf; } /* Return number of octets consumed from the input buffer (not the prefix length * in bytes), or -1 for encoding error. */ static int network_prefix(int ae, int plen, unsigned int omitted, const unsigned char *p, const unsigned char *dp, unsigned int len, unsigned char *p_r) { unsigned pb; unsigned char prefix[16]; int consumed = 0; if(plen >= 0) pb = (plen + 7) / 8; else if(ae == 1) pb = 4; else pb = 16; if(pb > 16) return -1; memset(prefix, 0, 16); switch(ae) { case 0: break; case 1: if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted)) return -1; memcpy(prefix, v4prefix, 12); if(omitted) { if (dp == NULL) return -1; memcpy(prefix, dp, 12 + omitted); } if(pb > omitted) { memcpy(prefix + 12 + omitted, p, pb - omitted); consumed = pb - omitted; } break; case 2: if(omitted > 16 || (pb > omitted && len < pb - omitted)) return -1; if(omitted) { if (dp == NULL) return -1; memcpy(prefix, dp, omitted); } if(pb > omitted) { memcpy(prefix + omitted, p, pb - omitted); consumed = pb - omitted; } break; case 3: if(pb > 8 && len < pb - 8) return -1; prefix[0] = 0xfe; prefix[1] = 0x80; if(pb > 8) { memcpy(prefix + 8, p, pb - 8); consumed = pb - 8; } break; default: return -1; } memcpy(p_r, prefix, 16); return consumed; } static int network_address(int ae, const unsigned char *a, unsigned int len, unsigned char *a_r) { return network_prefix(ae, -1, 0, a, NULL, len, a_r); } /* * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126), * their encoding is similar to the encoding of TLVs, but the type namespace is * different: * * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV. * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV. * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing * data. Its body is a variable-length sequence of 8-bit unsigned integers, * each representing per-hop number of interferring radio channel for the * prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel * 255 interferes with any other channel. * o Type 3 stands for Timestamp sub-TLV, used to compute RTT between * neighbours. In the case of a Hello TLV, the body stores a 32-bits * timestamp, while in the case of a IHU TLV, two 32-bits timestamps are * stored. * * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is * only valid for TLV type 8 (Update). Note that within an Update TLV a missing * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body. * The former would mean a lack of any claims about the interference, and the * latter would state that interference is definitely absent. * A type 3 sub-TLV is valid both for Hello and IHU TLVs, though the exact * semantic of the sub-TLV is different in each case. */ static void subtlvs_print(netdissect_options *ndo, const u_char *cp, const u_char *ep, const uint8_t tlv_type) { uint8_t subtype, sublen; const char *sep; uint32_t t1, t2; while (cp < ep) { subtype = *cp++; if(subtype == MESSAGE_SUB_PAD1) { ND_PRINT((ndo, " sub-pad1")); continue; } if(cp == ep) goto invalid; sublen = *cp++; if(cp + sublen > ep) goto invalid; switch(subtype) { case MESSAGE_SUB_PADN: ND_PRINT((ndo, " sub-padn")); cp += sublen; break; case MESSAGE_SUB_DIVERSITY: ND_PRINT((ndo, " sub-diversity")); if (sublen == 0) { ND_PRINT((ndo, " empty")); break; } sep = " "; while(sublen--) { ND_PRINT((ndo, "%s%s", sep, tok2str(diversity_str, "%u", *cp++))); sep = "-"; } if(tlv_type != MESSAGE_UPDATE && tlv_type != MESSAGE_UPDATE_SRC_SPECIFIC) ND_PRINT((ndo, " (bogus)")); break; case MESSAGE_SUB_TIMESTAMP: ND_PRINT((ndo, " sub-timestamp")); if(tlv_type == MESSAGE_HELLO) { if(sublen < 4) goto invalid; t1 = EXTRACT_32BITS(cp); ND_PRINT((ndo, " %s", format_timestamp(t1))); } else if(tlv_type == MESSAGE_IHU) { if(sublen < 8) goto invalid; t1 = EXTRACT_32BITS(cp); ND_PRINT((ndo, " %s", format_timestamp(t1))); t2 = EXTRACT_32BITS(cp + 4); ND_PRINT((ndo, "|%s", format_timestamp(t2))); } else ND_PRINT((ndo, " (bogus)")); cp += sublen; break; default: ND_PRINT((ndo, " sub-unknown-0x%02x", subtype)); cp += sublen; } /* switch */ } /* while */ return; invalid: ND_PRINT((ndo, "%s", istr)); } #define ICHECK(i, l) \ if ((i) + (l) > bodylen || (i) + (l) > length) goto invalid; static void babel_print_v2(netdissect_options *ndo, const u_char *cp, u_int length) { u_int i; u_short bodylen; u_char v4_prefix[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 }; u_char v6_prefix[16] = {0}; ND_TCHECK2(*cp, 4); if (length < 4) goto invalid; bodylen = EXTRACT_16BITS(cp + 2); ND_PRINT((ndo, " (%u)", bodylen)); /* Process the TLVs in the body */ i = 0; while(i < bodylen) { const u_char *message; u_int type, len; message = cp + 4 + i; ND_TCHECK2(*message, 1); if((type = message[0]) == MESSAGE_PAD1) { ND_PRINT((ndo, ndo->ndo_vflag ? "\n\tPad 1" : " pad1")); i += 1; continue; } ND_TCHECK2(*message, 2); ICHECK(i, 2); len = message[1]; ND_TCHECK2(*message, 2 + len); ICHECK(i, 2 + len); switch(type) { case MESSAGE_PADN: { if (!ndo->ndo_vflag) ND_PRINT((ndo, " padN")); else ND_PRINT((ndo, "\n\tPad %d", len + 2)); } break; case MESSAGE_ACK_REQ: { u_short nonce, interval; if (!ndo->ndo_vflag) ND_PRINT((ndo, " ack-req")); else { ND_PRINT((ndo, "\n\tAcknowledgment Request ")); if(len < 6) goto invalid; nonce = EXTRACT_16BITS(message + 4); interval = EXTRACT_16BITS(message + 6); ND_PRINT((ndo, "%04x %s", nonce, format_interval(interval))); } } break; case MESSAGE_ACK: { u_short nonce; if (!ndo->ndo_vflag) ND_PRINT((ndo, " ack")); else { ND_PRINT((ndo, "\n\tAcknowledgment ")); if(len < 2) goto invalid; nonce = EXTRACT_16BITS(message + 2); ND_PRINT((ndo, "%04x", nonce)); } } break; case MESSAGE_HELLO: { u_short seqno, interval; if (!ndo->ndo_vflag) ND_PRINT((ndo, " hello")); else { ND_PRINT((ndo, "\n\tHello ")); if(len < 6) goto invalid; seqno = EXTRACT_16BITS(message + 4); interval = EXTRACT_16BITS(message + 6); ND_PRINT((ndo, "seqno %u interval %s", seqno, format_interval(interval))); /* Extra data. */ if(len > 6) subtlvs_print(ndo, message + 8, message + 2 + len, type); } } break; case MESSAGE_IHU: { unsigned short txcost, interval; if (!ndo->ndo_vflag) ND_PRINT((ndo, " ihu")); else { u_char address[16]; int rc; ND_PRINT((ndo, "\n\tIHU ")); if(len < 6) goto invalid; txcost = EXTRACT_16BITS(message + 4); interval = EXTRACT_16BITS(message + 6); rc = network_address(message[2], message + 8, len - 6, address); if(rc < 0) { ND_PRINT((ndo, "%s", tstr)); break; } ND_PRINT((ndo, "%s txcost %u interval %s", format_address(ndo, address), txcost, format_interval(interval))); /* Extra data. */ if((u_int)rc < len - 6) subtlvs_print(ndo, message + 8 + rc, message + 2 + len, type); } } break; case MESSAGE_ROUTER_ID: { if (!ndo->ndo_vflag) ND_PRINT((ndo, " router-id")); else { ND_PRINT((ndo, "\n\tRouter Id")); if(len < 10) goto invalid; ND_PRINT((ndo, " %s", format_id(message + 4))); } } break; case MESSAGE_NH: { if (!ndo->ndo_vflag) ND_PRINT((ndo, " nh")); else { int rc; u_char nh[16]; ND_PRINT((ndo, "\n\tNext Hop")); if(len < 2) goto invalid; rc = network_address(message[2], message + 4, len - 2, nh); if(rc < 0) goto invalid; ND_PRINT((ndo, " %s", format_address(ndo, nh))); } } break; case MESSAGE_UPDATE: { if (!ndo->ndo_vflag) { ND_PRINT((ndo, " update")); if(len < 1) ND_PRINT((ndo, "/truncated")); else ND_PRINT((ndo, "%s%s%s", (message[3] & 0x80) ? "/prefix": "", (message[3] & 0x40) ? "/id" : "", (message[3] & 0x3f) ? "/unknown" : "")); } else { u_short interval, seqno, metric; u_char plen; int rc; u_char prefix[16]; ND_PRINT((ndo, "\n\tUpdate")); if(len < 10) goto invalid; plen = message[4] + (message[2] == 1 ? 96 : 0); rc = network_prefix(message[2], message[4], message[5], message + 12, message[2] == 1 ? v4_prefix : v6_prefix, len - 10, prefix); if(rc < 0) goto invalid; interval = EXTRACT_16BITS(message + 6); seqno = EXTRACT_16BITS(message + 8); metric = EXTRACT_16BITS(message + 10); ND_PRINT((ndo, "%s%s%s %s metric %u seqno %u interval %s", (message[3] & 0x80) ? "/prefix": "", (message[3] & 0x40) ? "/id" : "", (message[3] & 0x3f) ? "/unknown" : "", format_prefix(ndo, prefix, plen), metric, seqno, format_interval_update(interval))); if(message[3] & 0x80) { if(message[2] == 1) memcpy(v4_prefix, prefix, 16); else memcpy(v6_prefix, prefix, 16); } /* extra data? */ if((u_int)rc < len - 10) subtlvs_print(ndo, message + 12 + rc, message + 2 + len, type); } } break; case MESSAGE_REQUEST: { if (!ndo->ndo_vflag) ND_PRINT((ndo, " request")); else { int rc; u_char prefix[16], plen; ND_PRINT((ndo, "\n\tRequest ")); if(len < 2) goto invalid; plen = message[3] + (message[2] == 1 ? 96 : 0); rc = network_prefix(message[2], message[3], 0, message + 4, NULL, len - 2, prefix); if(rc < 0) goto invalid; ND_PRINT((ndo, "for %s", message[2] == 0 ? "any" : format_prefix(ndo, prefix, plen))); } } break; case MESSAGE_MH_REQUEST : { if (!ndo->ndo_vflag) ND_PRINT((ndo, " mh-request")); else { int rc; u_short seqno; u_char prefix[16], plen; ND_PRINT((ndo, "\n\tMH-Request ")); if(len < 14) goto invalid; seqno = EXTRACT_16BITS(message + 4); rc = network_prefix(message[2], message[3], 0, message + 16, NULL, len - 14, prefix); if(rc < 0) goto invalid; plen = message[3] + (message[2] == 1 ? 96 : 0); ND_PRINT((ndo, "(%u hops) for %s seqno %u id %s", message[6], format_prefix(ndo, prefix, plen), seqno, format_id(message + 8))); } } break; case MESSAGE_TSPC : if (!ndo->ndo_vflag) ND_PRINT((ndo, " tspc")); else { ND_PRINT((ndo, "\n\tTS/PC ")); if(len < 6) goto invalid; ND_PRINT((ndo, "timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4), EXTRACT_16BITS(message + 2))); } break; case MESSAGE_HMAC : { if (!ndo->ndo_vflag) ND_PRINT((ndo, " hmac")); else { unsigned j; ND_PRINT((ndo, "\n\tHMAC ")); if(len < 18) goto invalid; ND_PRINT((ndo, "key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2)); for (j = 0; j < len - 2; j++) ND_PRINT((ndo, "%02X", message[4 + j])); } } break; case MESSAGE_UPDATE_SRC_SPECIFIC : { if(!ndo->ndo_vflag) { ND_PRINT((ndo, " ss-update")); } else { u_char prefix[16], src_prefix[16]; u_short interval, seqno, metric; u_char ae, plen, src_plen, omitted; int rc; int parsed_len = 10; ND_PRINT((ndo, "\n\tSS-Update")); if(len < 10) goto invalid; ae = message[2]; src_plen = message[3]; plen = message[4]; omitted = message[5]; interval = EXTRACT_16BITS(message + 6); seqno = EXTRACT_16BITS(message + 8); metric = EXTRACT_16BITS(message + 10); rc = network_prefix(ae, plen, omitted, message + 2 + parsed_len, ae == 1 ? v4_prefix : v6_prefix, len - parsed_len, prefix); if(rc < 0) goto invalid; if(ae == 1) plen += 96; parsed_len += rc; rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len, NULL, len - parsed_len, src_prefix); if(rc < 0) goto invalid; if(ae == 1) src_plen += 96; parsed_len += rc; ND_PRINT((ndo, " %s from", format_prefix(ndo, prefix, plen))); ND_PRINT((ndo, " %s metric %u seqno %u interval %s", format_prefix(ndo, src_prefix, src_plen), metric, seqno, format_interval_update(interval))); /* extra data? */ if((u_int)parsed_len < len) subtlvs_print(ndo, message + 2 + parsed_len, message + 2 + len, type); } } break; case MESSAGE_REQUEST_SRC_SPECIFIC : { if(!ndo->ndo_vflag) ND_PRINT((ndo, " ss-request")); else { int rc, parsed_len = 3; u_char ae, plen, src_plen, prefix[16], src_prefix[16]; ND_PRINT((ndo, "\n\tSS-Request ")); if(len < 3) goto invalid; ae = message[2]; plen = message[3]; src_plen = message[4]; rc = network_prefix(ae, plen, 0, message + 2 + parsed_len, NULL, len - parsed_len, prefix); if(rc < 0) goto invalid; if(ae == 1) plen += 96; parsed_len += rc; rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len, NULL, len - parsed_len, src_prefix); if(rc < 0) goto invalid; if(ae == 1) src_plen += 96; parsed_len += rc; if(ae == 0) { ND_PRINT((ndo, "for any")); } else { ND_PRINT((ndo, "for (%s, ", format_prefix(ndo, prefix, plen))); ND_PRINT((ndo, "%s)", format_prefix(ndo, src_prefix, src_plen))); } } } break; case MESSAGE_MH_REQUEST_SRC_SPECIFIC : { if(!ndo->ndo_vflag) ND_PRINT((ndo, " ss-mh-request")); else { int rc, parsed_len = 14; u_short seqno; u_char ae, plen, src_plen, prefix[16], src_prefix[16], hopc; const u_char *router_id = NULL; ND_PRINT((ndo, "\n\tSS-MH-Request ")); if(len < 14) goto invalid; ae = message[2]; plen = message[3]; seqno = EXTRACT_16BITS(message + 4); hopc = message[6]; src_plen = message[7]; router_id = message + 8; rc = network_prefix(ae, plen, 0, message + 2 + parsed_len, NULL, len - parsed_len, prefix); if(rc < 0) goto invalid; if(ae == 1) plen += 96; parsed_len += rc; rc = network_prefix(ae, src_plen, 0, message + 2 + parsed_len, NULL, len - parsed_len, src_prefix); if(rc < 0) goto invalid; if(ae == 1) src_plen += 96; ND_PRINT((ndo, "(%u hops) for (%s, ", hopc, format_prefix(ndo, prefix, plen))); ND_PRINT((ndo, "%s) seqno %u id %s", format_prefix(ndo, src_prefix, src_plen), seqno, format_id(router_id))); } } break; default: if (!ndo->ndo_vflag) ND_PRINT((ndo, " unknown")); else ND_PRINT((ndo, "\n\tUnknown message type %d", type)); } i += len + 2; } return; trunc: ND_PRINT((ndo, " %s", tstr)); return; invalid: ND_PRINT((ndo, "%s", istr)); return; }