/* resolv.c * Routines for network object lookup * * $Id: resolv.c,v 1.8 1999/07/13 02:52:58 gram Exp $ * * Laurent Deniel * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #ifndef WIN32 #ifndef AVOID_DNS_TIMEOUT #define AVOID_DNS_TIMEOUT #endif #endif #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_SYS_TYPES_H # include #endif #ifdef HAVE_NETINET_IN_H # include #endif #ifdef HAVE_NETDB_H #include #endif #include #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef AVOID_DNS_TIMEOUT # include #endif #include "ethereal.h" #include "packet.h" #include "packet-ipv6.h" #include "resolv.h" #ifndef MAXNAMELEN #define MAXNAMELEN 64 /* max name length (hostname and port name) */ #endif #define MAXMANUFLEN 9 /* max vendor name length with ending '\0' */ #define HASHETHSIZE 1024 #define HASHHOSTSIZE 1024 #define HASHMANUFSIZE 256 #define HASHPORTSIZE 256 /* hash table used for host and port lookup */ typedef struct hashname { u_int addr; u_char name[MAXNAMELEN]; struct hashname *next; } hashname_t; /* hash tables used for ethernet and manufacturer lookup */ typedef struct hashmanuf { u_char addr[3]; char name[MAXMANUFLEN]; struct hashmanuf *next; } hashmanuf_t; typedef struct hashether { u_char addr[6]; char name[MAXNAMELEN]; struct hashether *next; } hashether_t; /* internal ethernet type */ typedef struct _ether { u_char addr[6]; char name[MAXNAMELEN]; } ether_t; static hashname_t *host_table[HASHHOSTSIZE]; static hashname_t *udp_port_table[HASHPORTSIZE]; static hashname_t *tcp_port_table[HASHPORTSIZE]; static hashether_t *eth_table[HASHETHSIZE]; static hashmanuf_t *manuf_table[HASHMANUFSIZE]; static int eth_resolution_initialized = 0; /* * Global variables (can be changed in GUI sections) */ int g_resolving_actif = 1; /* routines are active by default */ gchar *g_ethers_path = EPATH_ETHERS; gchar *g_pethers_path = NULL; /* "$HOME"/EPATH_PERSONAL_ETHERS */ gchar *g_manuf_path = EPATH_MANUF; /* may only be changed before the */ /* first resolving call */ /* * Local function definitions */ static u_char *serv_name_lookup(u_int port, u_int proto) { hashname_t *tp; hashname_t **table; char *serv_proto = NULL; struct servent *servp; int i; switch(proto) { case IPPROTO_UDP: table = udp_port_table; serv_proto = "udp"; break; case IPPROTO_TCP: table = tcp_port_table; serv_proto = "tcp"; break; default: /* not yet implemented */ return NULL; /*NOTREACHED*/ break; } /* proto */ i = port & (HASHPORTSIZE - 1); tp = table[ i & (HASHPORTSIZE - 1)]; if( tp == NULL ) { tp = table[ i & (HASHPORTSIZE - 1)] = (hashname_t *)g_malloc(sizeof(hashname_t)); } else { while(1) { if( tp->addr == port ) { return tp->name; } if (tp->next == NULL) { tp->next = (hashname_t *)g_malloc(sizeof(hashname_t)); tp = tp->next; break; } tp = tp->next; } } /* fill in a new entry */ tp->addr = port; tp->next = NULL; if ((servp = getservbyport(htons(port), serv_proto)) == NULL) { /* unknown port */ sprintf(tp->name, "%d", port); } else { strncpy(tp->name, servp->s_name, MAXNAMELEN); tp->name[MAXNAMELEN-1] = '\0'; } return (tp->name); } /* serv_name_lookup */ #ifdef AVOID_DNS_TIMEOUT #define DNS_TIMEOUT 5 /* max sec per call */ jmp_buf hostname_env; static void abort_network_query(int sig) { longjmp(hostname_env, 1); } #endif /* AVOID_DNS_TIMEOUT */ static u_char *host_name_lookup(u_int addr) { hashname_t * volatile tp; hashname_t **table = host_table; struct hostent *hostp; tp = table[ addr & (HASHHOSTSIZE - 1)]; if( tp == NULL ) { tp = table[ addr & (HASHHOSTSIZE - 1)] = (hashname_t *)g_malloc(sizeof(hashname_t)); } else { while(1) { if( tp->addr == addr ) { return tp->name; } if (tp->next == NULL) { tp->next = (hashname_t *)g_malloc(sizeof(hashname_t)); tp = tp->next; break; } tp = tp->next; } } /* fill in a new entry */ tp->addr = addr; tp->next = NULL; #ifdef AVOID_DNS_TIMEOUT /* Quick hack to avoid DNS/YP timeout */ if (!setjmp(hostname_env)) { signal(SIGALRM, abort_network_query); alarm(DNS_TIMEOUT); #endif hostp = gethostbyaddr((char *)&addr, 4, AF_INET); #ifdef AVOID_DNS_TIMEOUT alarm(0); #endif if (hostp != NULL) { strncpy(tp->name, hostp->h_name, MAXNAMELEN); tp->name[MAXNAMELEN-1] = '\0'; return tp->name; } #ifdef AVOID_DNS_TIMEOUT } #endif /* unknown host or DNS timeout */ sprintf(tp->name, "%s", ip_to_str((guint8 *)&addr)); return (tp->name); } /* host_name_lookup */ static u_char *host_name_lookup6(struct e_in6_addr *addr) { static u_char name[MAXNAMELEN]; #ifdef INET6 struct hostent *hostp; #ifdef AVOID_DNS_TIMEOUT /* Quick hack to avoid DNS/YP timeout */ if (!setjmp(hostname_env)) { signal(SIGALRM, abort_network_query); alarm(DNS_TIMEOUT); #endif /* AVOID_DNS_TIMEOUT */ hostp = gethostbyaddr((char *)addr, sizeof(*addr), AF_INET6); #ifdef AVOID_DNS_TIMEOUT alarm(0); #endif if (hostp != NULL) { strncpy(name, hostp->h_name, MAXNAMELEN); name[MAXNAMELEN-1] = '\0'; return name; } #ifdef AVOID_DNS_TIMEOUT } #endif /* unknown host or DNS timeout */ #endif /* INET6 */ sprintf(name, "%s", ip6_to_str(addr)); return (name); } /* * Miscellaneous functions */ static int fgetline(char **buf, int *size, FILE *fp) { int len; int c; if (fp == NULL) return -1; if (*buf == NULL) { if (*size == 0) *size = BUFSIZ; if ((*buf = g_malloc(*size)) == NULL) return -1; } if (feof(fp)) return -1; len = 0; while ((c = getc(fp)) != EOF && c != '\n') { if (len+1 >= *size) { if ((*buf = g_realloc(*buf, *size += BUFSIZ)) == NULL) return -1; } (*buf)[len++] = c; } if (len == 0 && c == EOF) return -1; (*buf)[len] = '\0'; return len; } /* fgetline */ /* * Ethernet / manufacturer resolution * * The following functions implement ethernet address resolution and * ethers files parsing (see ethers(4)). * * /etc/manuf has the same format as ethers(4) except that names are * truncated to MAXMANUFLEN-1 characters and that an address contains * only 3 bytes (instead of 6). * * Notes: * * I decide to not use the existing functions (see ethers(3) on some * operating systems) for the following reasons: * - performance gains (use of hash tables and some other enhancements), * - use of two ethers files (system-wide and per user), * - avoid the use of NIS maps, * - lack of these functions on some systems. * * So the following functions do _not_ behave as the standard ones. * * -- Laurent. */ static int parse_ether_line(char *line, ether_t *eth, int six_bytes) { /* * See man ethers(4) for /etc/ethers file format * (not available on all systems). * We allow both ethernet address separators (':' and '-'). */ gchar *cp; int a0, a1, a2, a3, a4, a5; if ((cp = strchr(line, '#'))) *cp = '\0'; if ((cp = strtok(line, " \t\n")) == NULL) return -1; if (six_bytes) { if (sscanf(cp, "%x:%x:%x:%x:%x:%x", &a0, &a1, &a2, &a3, &a4, &a5) != 6) { if (sscanf(cp, "%x-%x-%x-%x-%x-%x", &a0, &a1, &a2, &a3, &a4, &a5) != 6) return -1; } } else { if (sscanf(cp, "%x:%x:%x", &a0, &a1, &a2) != 3) { if (sscanf(cp, "%x-%x-%x", &a0, &a1, &a2) != 3) return -1; } } if ((cp = strtok(NULL, " \t\n")) == NULL) return -1; eth->addr[0] = a0; eth->addr[1] = a1; eth->addr[2] = a2; if (six_bytes) { eth->addr[3] = a3; eth->addr[4] = a4; eth->addr[5] = a5; } else { eth->addr[3] = 0; eth->addr[4] = 0; eth->addr[5] = 0; } strncpy(eth->name, cp, MAXNAMELEN); eth->name[MAXNAMELEN-1] = '\0'; return 0; } /* parse_ether_line */ static FILE *eth_p = NULL; static void set_ethent(char *path) { if (eth_p) rewind(eth_p); else eth_p = fopen(path, "r"); } static void end_ethent(void) { if (eth_p) { fclose(eth_p); eth_p = NULL; } } static ether_t *get_ethent(int six_bytes) { static ether_t eth; static int size = 0; static char *buf = NULL; if (eth_p == NULL) return NULL; while (fgetline(&buf, &size, eth_p) >= 0) { if (parse_ether_line(buf, ð, six_bytes) == 0) { return ð } } return NULL; } /* get_ethent */ static ether_t *get_ethbyname(u_char *name) { ether_t *eth; set_ethent(g_ethers_path); while ((eth = get_ethent(1)) && strncmp(name, eth->name, MAXNAMELEN) != 0) ; if (eth == NULL) { end_ethent(); set_ethent(g_pethers_path); while ((eth = get_ethent(1)) && strncmp(name, eth->name, MAXNAMELEN) != 0) ; end_ethent(); } return eth; } /* get_ethbyname */ static ether_t *get_ethbyaddr(u_char *addr) { ether_t *eth; set_ethent(g_ethers_path); while ((eth = get_ethent(1)) && memcmp(addr, eth->addr, 6) != 0) ; if (eth == NULL) { end_ethent(); set_ethent(g_pethers_path); while ((eth = get_ethent(1)) && memcmp(addr, eth->addr, 6) != 0) ; end_ethent(); } return eth; } /* get_ethbyaddr */ static void add_manuf_name(u_char *addr, u_char *name) { hashmanuf_t *tp; hashmanuf_t **table = manuf_table; tp = table[ ((int)addr[2]) & (HASHMANUFSIZE - 1)]; if( tp == NULL ) { tp = table[ ((int)addr[2]) & (HASHMANUFSIZE - 1)] = (hashmanuf_t *)g_malloc(sizeof(hashmanuf_t)); } else { while(1) { if (tp->next == NULL) { tp->next = (hashmanuf_t *)g_malloc(sizeof(hashmanuf_t)); tp = tp->next; break; } tp = tp->next; } } memcpy(tp->addr, addr, sizeof(tp->addr)); strncpy(tp->name, name, MAXMANUFLEN); tp->name[MAXMANUFLEN-1] = '\0'; tp->next = NULL; } /* add_manuf_name */ static hashmanuf_t *manuf_name_lookup(u_char *addr) { hashmanuf_t *tp; hashmanuf_t **table = manuf_table; tp = table[ ((int)addr[2]) & (HASHMANUFSIZE - 1)]; while(tp != NULL) { if (memcmp(tp->addr, addr, sizeof(tp->addr)) == 0) { return tp; } tp = tp->next; } return NULL; } /* manuf_name_lookup */ static hashether_t *add_eth_name(u_char *addr, u_char *name) { hashether_t *tp; hashether_t **table = eth_table; int i,j; j = (addr[2] << 8) | addr[3]; i = (addr[4] << 8) | addr[5]; tp = table[ (i ^ j) & (HASHETHSIZE - 1)]; if( tp == NULL ) { tp = table[ (i ^ j) & (HASHETHSIZE - 1)] = (hashether_t *)g_malloc(sizeof(hashether_t)); } else { while(1) { if (tp->next == NULL) { tp->next = (hashether_t *)g_malloc(sizeof(hashether_t)); tp = tp->next; break; } tp = tp->next; } } memcpy(tp->addr, addr, sizeof(tp->addr)); strncpy(tp->name, name, MAXNAMELEN); tp->name[MAXNAMELEN-1] = '\0'; tp->next = NULL; return tp; } /* add_eth_name */ static u_char *eth_name_lookup(u_char *addr) { hashmanuf_t *manufp; hashether_t *tp; hashether_t **table = eth_table; ether_t *eth; int i,j; j = (addr[2] << 8) | addr[3]; i = (addr[4] << 8) | addr[5]; tp = table[ (i ^ j) & (HASHETHSIZE - 1)]; if( tp == NULL ) { tp = table[ (i ^ j) & (HASHETHSIZE - 1)] = (hashether_t *)g_malloc(sizeof(hashether_t)); } else { while(1) { if (memcmp(tp->addr, addr, sizeof(tp->addr)) == 0) { return tp->name; } if (tp->next == NULL) { tp->next = (hashether_t *)g_malloc(sizeof(hashether_t)); tp = tp->next; break; } tp = tp->next; } } /* fill in a new entry */ memcpy(tp->addr, addr, sizeof(tp->addr)); tp->next = NULL; if ( (eth = get_ethbyaddr(addr)) == NULL) { /* unknown name */ if ((manufp = manuf_name_lookup(addr)) == NULL) sprintf(tp->name, "%s", ether_to_str((guint8 *)addr)); else sprintf(tp->name, "%s_%02x:%02x:%02x", manufp->name, addr[3], addr[4], addr[5]); } else { strncpy(tp->name, eth->name, MAXNAMELEN); tp->name[MAXNAMELEN-1] = '\0'; } return (tp->name); } /* eth_name_lookup */ static u_char *eth_addr_lookup(u_char *name) { ether_t *eth; hashether_t *tp; hashether_t **table = eth_table; int i; /* to be optimized (hash table from name to addr) */ for (i = 0; i < HASHETHSIZE; i++) { tp = table[i]; while (tp) { if (strcmp(tp->name, name) == 0) return tp->addr; tp = tp->next; } } /* not in hash table : performs a file lookup */ if ((eth = get_ethbyname(name)) == NULL) return NULL; /* add new entry in hash table */ tp = add_eth_name(eth->addr, name); return tp->addr; } /* eth_addr_lookup */ static void initialize_ethers(void) { ether_t *eth; #ifdef DEBUG_RESOLV signal(SIGSEGV, SIG_IGN); #endif if (g_pethers_path == NULL) { g_pethers_path = g_malloc(strlen(getenv("HOME")) + strlen(EPATH_PERSONAL_ETHERS) + 2); sprintf(g_pethers_path, "%s/%s", (char *)getenv("HOME"), EPATH_PERSONAL_ETHERS); } /* manuf hash table initialization */ set_ethent(g_manuf_path); while ((eth = get_ethent(0))) { add_manuf_name(eth->addr, eth->name); } end_ethent(); } /* initialize_ethers */ /* * External Functions */ extern u_char *get_hostname(u_int addr) { if (!g_resolving_actif) return ip_to_str((guint8 *)&addr); return host_name_lookup(addr); } extern gchar *get_hostname6(struct e_in6_addr *addr) { #ifdef INET6 if (!g_resolving_actif) return ip6_to_str(addr); if (IN6_IS_ADDR_LINKLOCAL(addr) || IN6_IS_ADDR_MULTICAST(addr)) return ip6_to_str(addr); #endif return host_name_lookup6(addr); } extern void add_host_name(u_int addr, u_char *name) { hashname_t *tp; hashname_t **table = host_table; tp = table[ addr & (HASHHOSTSIZE - 1)]; if( tp == NULL ) { tp = table[ addr & (HASHHOSTSIZE - 1)] = (hashname_t *)g_malloc(sizeof(hashname_t)); } else { while(1) { if (tp->next == NULL) { tp->next = (hashname_t *)g_malloc(sizeof(hashname_t)); tp = tp->next; break; } tp = tp->next; } } strncpy(tp->name, name, MAXNAMELEN); tp->name[MAXNAMELEN-1] = '\0'; tp->addr = addr; tp->next = NULL; } /* add_host_name */ extern u_char *get_udp_port(u_int port) { static gchar str[3][MAXNAMELEN]; static gchar *cur; if (!g_resolving_actif) { if (cur == &str[0][0]) { cur = &str[1][0]; } else if (cur == &str[1][0]) { cur = &str[2][0]; } else { cur = &str[0][0]; } sprintf(cur, "%d", port); return cur; } return serv_name_lookup(port, IPPROTO_UDP); } /* get_udp_port */ extern u_char *get_tcp_port(u_int port) { static gchar str[3][MAXNAMELEN]; static gchar *cur; if (!g_resolving_actif) { if (cur == &str[0][0]) { cur = &str[1][0]; } else if (cur == &str[1][0]) { cur = &str[2][0]; } else { cur = &str[0][0]; } sprintf(cur, "%d", port); return cur; } return serv_name_lookup(port, IPPROTO_TCP); } /* get_tcp_port */ extern u_char *get_ether_name(u_char *addr) { if (!g_resolving_actif) return ether_to_str((guint8 *)addr); if (!eth_resolution_initialized) { initialize_ethers(); eth_resolution_initialized = 1; } return eth_name_lookup(addr); } /* get_ether_name */ extern u_char *get_ether_addr(u_char *name) { /* force resolution (do not check g_resolving_actif) */ if (!eth_resolution_initialized) { initialize_ethers(); eth_resolution_initialized = 1; } return eth_addr_lookup(name); } /* get_ether_addr */ extern u_char *get_manuf_name(u_char *addr) { static gchar str[3][MAXMANUFLEN]; static gchar *cur; hashmanuf_t *manufp; if (g_resolving_actif && !eth_resolution_initialized) { initialize_ethers(); eth_resolution_initialized = 1; } if (!g_resolving_actif || ((manufp = manuf_name_lookup(addr)) == NULL)) { if (cur == &str[0][0]) { cur = &str[1][0]; } else if (cur == &str[1][0]) { cur = &str[2][0]; } else { cur = &str[0][0]; } sprintf(cur, "%02x:%02x:%02x", addr[0], addr[1], addr[2]); return cur; } return manufp->name; } /* get_manuf_name */ /* return IP address of either hostname or IP address in text format. * Used more in the dfilter parser rather than in packet dissectors */ unsigned long get_host_ipaddr(const char *host) { struct hostent *hp = NULL; unsigned long ipaddr; hp = gethostbyname(host); if (hp == NULL) { hp = gethostbyaddr(host, strlen(host), AF_INET); if (hp == NULL) { return 0; } } memcpy(&ipaddr, hp->h_addr, hp->h_length); return ntohl(ipaddr); }