/* Copyright 2001-2003 Roger Dingledine, Matej Pfajfar. */ /* See LICENSE for licensing information */ /* $Id$ */ /** * \file routerparse.c * * \brief Code to parse and validate router descriptors and directories. **/ /* This is required on rh7 to make strptime not complain. */ #define _GNU_SOURCE #include "or.h" /****************************************************************************/ /** Enumeration of possible token types. The ones starting with K_ * correspond to directory 'keywords'. _UNRECOGNIZED is for an * unrecognized keyword; _ERR is an error in the tokenizing process, * _EOF is an end-of-file marker, and _NIL is used to encode * not-a-token. */ typedef enum { K_ACCEPT, K_DIRECTORY_SIGNATURE, K_RECOMMENDED_SOFTWARE, K_REJECT, K_ROUTER, K_SIGNED_DIRECTORY, K_SIGNING_KEY, K_ONION_KEY, K_LINK_KEY, /* XXXX obsolete; remove in June. */ K_ROUTER_SIGNATURE, K_PUBLISHED, K_RUNNING_ROUTERS, K_PLATFORM, K_OPT, K_BANDWIDTH, K_PORTS, K_DIRCACHEPORT, K_CONTACT, K_NETWORK_STATUS, _UNRECOGNIZED, _ERR, _EOF, _NIL } directory_keyword; /** Structure to hold a single directory token. * * We parse a directory by breaking it into "tokens", each consisting * of a keyword, a line full of arguments, and a binary object. The * arguments and object are both optional, depending on the keyword * type. */ typedef struct directory_token_t { directory_keyword tp; /**< Type of the token. */ int n_args; /**< Number of elements in args */ char **args; /**< Array of arguments from keyword line. */ char *object_type; /**< -----BEGIN [object_type]-----*/ int object_size; /**< Bytes in object_body */ char *object_body; /**< Contents of object, base64-decoded. */ crypto_pk_env_t *key; /**< For public keys only. */ char *error; /**< For _ERR tokens only. */ } directory_token_t; /* ********************************************************************** */ /** We use a table of rules to decide how to parse each token type. */ /** Rules for how many arguments a keyword can take. */ typedef enum { NO_ARGS, /**< (1) no arguments, ever */ ARGS, /**< (2) a list of arguments separated by spaces */ CONCAT_ARGS, /**< or (3) the rest of the line, treated as a single argument. */ } arg_syntax; /** Rules for whether the keyword needs an object. */ typedef enum { NO_OBJ, /**< (1) no object, ever */ NEED_OBJ, /**< (2) object is required */ NEED_KEY, /**< (3) object is required, and must be a public key. */ OBJ_OK, /**< or (4) object is optional. */ } obj_syntax; /** Rules for where a keyword can appear. */ typedef enum { ANY = 0, /**< Appears in router descriptor or in directory sections. */ DIR_ONLY, /**< Appears only in directory. */ RTR_ONLY, /**< Appears only in router descriptor or runningrouters */ } where_syntax; /** Table mapping keywords to token value and to argument rules. */ static struct { char *t; int v; arg_syntax s; obj_syntax os; where_syntax ws; } token_table[] = { { "accept", K_ACCEPT, ARGS, NO_OBJ, RTR_ONLY }, { "directory-signature", K_DIRECTORY_SIGNATURE, ARGS, NEED_OBJ,DIR_ONLY}, { "reject", K_REJECT, ARGS, NO_OBJ, RTR_ONLY }, { "router", K_ROUTER, ARGS, NO_OBJ, RTR_ONLY }, { "recommended-software",K_RECOMMENDED_SOFTWARE,ARGS, NO_OBJ, DIR_ONLY }, { "signed-directory", K_SIGNED_DIRECTORY, NO_ARGS, NO_OBJ, DIR_ONLY }, { "signing-key", K_SIGNING_KEY, NO_ARGS, NEED_KEY,RTR_ONLY }, { "onion-key", K_ONION_KEY, NO_ARGS, NEED_KEY,RTR_ONLY }, { "link-key", K_LINK_KEY, NO_ARGS, NEED_KEY,RTR_ONLY }, { "router-signature", K_ROUTER_SIGNATURE, NO_ARGS, NEED_OBJ,RTR_ONLY }, { "running-routers", K_RUNNING_ROUTERS, ARGS, NO_OBJ, DIR_ONLY }, { "ports", K_PORTS, ARGS, NO_OBJ, RTR_ONLY }, { "bandwidth", K_BANDWIDTH, ARGS, NO_OBJ, RTR_ONLY }, { "platform", K_PLATFORM, CONCAT_ARGS, NO_OBJ, RTR_ONLY }, { "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ, ANY }, { "opt", K_OPT, CONCAT_ARGS, OBJ_OK, ANY }, { "dircacheport", K_DIRCACHEPORT, ARGS, NO_OBJ, RTR_ONLY }, { "contact", K_CONTACT, CONCAT_ARGS, NO_OBJ, ANY }, { "network-status", K_NETWORK_STATUS, NO_ARGS, NO_OBJ, DIR_ONLY }, { NULL, -1 } }; /* static function prototypes */ static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok); static struct exit_policy_t *router_parse_exit_policy(directory_token_t *tok); static int router_get_hash_impl(const char *s, char *digest, const char *start_str, const char *end_str); static void token_free(directory_token_t *tok); static smartlist_t *find_all_exitpolicy(smartlist_t *s); static directory_token_t *find_first_by_keyword(smartlist_t *s, directory_keyword keyword); static int tokenize_string(const char *start, const char *end, smartlist_t *out, int is_dir); static directory_token_t *get_next_token(const char **s, where_syntax where); static int check_directory_signature(const char *digest, directory_token_t *tok, crypto_pk_env_t *pkey); /** Set <b>digest</b> to the SHA-1 digest of the hash of the directory in * <b>s</b>. Return 0 on success, nonzero on failure. */ int router_get_dir_hash(const char *s, char *digest) { return router_get_hash_impl(s,digest, "signed-directory","directory-signature"); } /** Set <b>digest</b> to the SHA-1 digest of the hash of the first router in * <b>s</b>. Return 0 on success, nonzero on failure. */ int router_get_router_hash(const char *s, char *digest) { return router_get_hash_impl(s,digest, "router ","router-signature"); } /** DOCDOC */ int router_get_runningrouters_hash(const char *s, char *digest) { return router_get_hash_impl(s,digest, "network-status ","directory-signature"); } /** Parse a date of the format "YYYY-MM-DD hh:mm:ss" and store the result into * *<b>t</b>. */ /* XXX this should go in util.c, yes? -RD */ static int parse_time(const char *cp, time_t *t) { struct tm st_tm; #ifdef HAVE_STRPTIME if (!strptime(cp, "%Y-%m-%d %H:%M:%S", &st_tm)) { log_fn(LOG_WARN, "Published time was unparseable"); return -1; } #else unsigned int year=0, month=0, day=0, hour=100, minute=100, second=100; if (sscanf(cp, "%u-%u-%u %u:%u:%u", &year, &month, &day, &hour, &minute, &second) < 6) { log_fn(LOG_WARN, "Published time was unparseable"); return -1; } if (year < 1970 || month < 1 || month > 12 || day < 1 || day > 31 || hour > 23 || minute > 59 || second > 61) { log_fn(LOG_WARN, "Published time was nonsensical"); return -1; } st_tm.tm_year = year; st_tm.tm_mon = month-1; st_tm.tm_mday = day; st_tm.tm_hour = hour; st_tm.tm_min = minute; st_tm.tm_sec = second; #endif *t = tor_timegm(&st_tm); return 0; } /** * Find the first instance of "recommended-software ...\n" at the start of * a line; return a newly allocated string containing the "..." portion. * Return NULL if no such instance was found. */ static char * get_recommended_software_from_directory(const char *str) { #define REC "recommended-software " const char *cp = str, *eol; int len = strlen(REC); cp = str; if (strncmp(str, REC, len)==0) { cp += len; } else { cp = strstr(str, "\n"REC); if (!cp) return NULL; cp += len+1; } eol = strchr(cp, '\n'); if (!eol) return NULL; return tor_strndup(cp, eol-cp); #undef REC } /** Return 1 if myversion is in versionlist. Else return 0. * (versionlist is a comma-separated list of versions.) */ /* static */ int is_recommended_version(const char *myversion, const char *versionlist) { int len_myversion = strlen(myversion); char *comma; const char *end = versionlist + strlen(versionlist); log_fn(LOG_DEBUG,"checking '%s' in '%s'.", myversion, versionlist); for(;;) { comma = strchr(versionlist, ','); if( ((comma ? comma : end) - versionlist == len_myversion) && !strncmp(versionlist, myversion, len_myversion)) /* only do strncmp if the length matches */ return 1; /* success, it's there */ if(!comma) return 0; /* nope */ versionlist = comma+1; } } /* Return 0 if myversion is supported; else log a message and return * -1 (or exit if ignoreversions is false) */ int check_software_version_against_directory(const char *directory, int ignoreversion) { char *v; v = get_recommended_software_from_directory(directory); if (!v) { log_fn(LOG_WARN, "No recommended-versions string found in directory"); return -1; } /* Look for versions of the form "0.1.0" and of the form "Tor 0.1.0". * Eventually, we should deprecate the first form. */ if (is_recommended_version(VERSION, v) || is_recommended_version("Tor "VERSION, v)) { tor_free(v); return 0; } log(ignoreversion ? LOG_WARN : LOG_ERR, "You are running Tor version %s, which will not work with this network.\n" "Please use %s%s.", VERSION, strchr(v,',') ? "one of " : "", v); tor_free(v); if(ignoreversion) { log(LOG_WARN, "IgnoreVersion is set. If it breaks, we told you so."); return -1; } else { fflush(0); exit(0); return -1; /* never reached */ } } /** Parse a directory from <b>s</b> and, when done, store the * resulting routerlist in *<b>dest</b>, freeing the old value if necessary. * If <b>pkey</b> is provided, we check the directory signature with pkey. */ int /* Should be static; exposed for unit tests */ router_parse_routerlist_from_directory(const char *str, routerlist_t **dest, crypto_pk_env_t *pkey) { directory_token_t *tok; char digest[DIGEST_LEN]; routerlist_t *new_dir = NULL; char *versions = NULL; int n_good_nicknames = 0; char *good_nickname_lst[1024]; /* XXXX008 correct this limit. */ time_t published_on; int i, r; const char *end; smartlist_t *tokens = NULL; if (router_get_dir_hash(str, digest)) { log_fn(LOG_WARN, "Unable to compute digest of directory"); goto err; } log(LOG_DEBUG,"Received directory hashes to %s",hex_str(digest,4)); if ((end = strstr(str,"\nrouter "))) { ++end; } else if ((end = strstr(str, "\ndirectory-signature"))) { ++end; } else { end = str + strlen(str); } tokens = smartlist_create(); if (tokenize_string(str,end,tokens,1)) { log_fn(LOG_WARN, "Error tokenizing directory"); goto err; } if (smartlist_len(tokens) < 1) { log_fn(LOG_WARN, "Impossibly short directory header"); goto err; } if ((tok = find_first_by_keyword(tokens, _UNRECOGNIZED))) { log_fn(LOG_WARN, "Unrecognized keyword in \"%s\"; can't parse directory.", tok->args[0]); goto err; } tok = smartlist_get(tokens,0); if (tok->tp != K_SIGNED_DIRECTORY) { log_fn(LOG_WARN, "Directory doesn't start with signed-directory."); goto err; } if (!(tok = find_first_by_keyword(tokens, K_PUBLISHED))) { log_fn(LOG_WARN, "Missing published time on directory."); goto err; } tor_assert(tok->n_args == 1); if (parse_time(tok->args[0], &published_on) < 0) { goto err; } if (!(tok = find_first_by_keyword(tokens, K_RECOMMENDED_SOFTWARE))) { log_fn(LOG_WARN, "Missing recommended-software line from directory."); goto err; } if (tok->n_args != 1) { log_fn(LOG_WARN, "Invalid recommended-software line"); goto err; } versions = tor_strdup(tok->args[0]); if (!(tok = find_first_by_keyword(tokens, K_RUNNING_ROUTERS))) { log_fn(LOG_WARN, "Missing running-routers line from directory."); goto err; } n_good_nicknames = tok->n_args; memcpy(good_nickname_lst, tok->args, n_good_nicknames*sizeof(char *)); tok->n_args = 0; /* Don't free the strings in good_nickname_lst yet. */ /* Read the router list from s, advancing s up past the end of the last * router. */ str = end; if (router_parse_list_from_string(&str, &new_dir, n_good_nicknames, (const char**)good_nickname_lst)) { log_fn(LOG_WARN, "Error reading routers from directory"); goto err; } for (i = 0; i < n_good_nicknames; ++i) { tor_free(good_nickname_lst[i]); /* now free them */ } new_dir->software_versions = versions; versions = NULL; new_dir->published_on = published_on; SMARTLIST_FOREACH(tokens, directory_token_t *, tok, token_free(tok)); smartlist_free(tokens); tokens = smartlist_create(); if (tokenize_string(str,str+strlen(str),tokens,1)<0) { log_fn(LOG_WARN, "Error tokenizing signature"); goto err; } if (smartlist_len(tokens) != 1 || (!(tok=smartlist_get(tokens,0))) || /* always succeeds */ (tok->tp != K_DIRECTORY_SIGNATURE)) { log_fn(LOG_WARN,"Expected a single directory signature"); goto err; } if (check_directory_signature(digest, smartlist_get(tokens,0), pkey)<0) { goto err; } if (*dest) routerlist_free(*dest); *dest = new_dir; r = 0; goto done; err: r = -1; if (new_dir) routerlist_free(new_dir); tor_free(versions); for (i = 0; i < n_good_nicknames; ++i) { tor_free(good_nickname_lst[i]); } done: if (tokens) { SMARTLIST_FOREACH(tokens, directory_token_t *, tok, token_free(tok)); smartlist_free(tokens); } return r; } running_routers_t * router_parse_runningrouters(const char *str) { char digest[DIGEST_LEN]; running_routers_t *new_list = NULL; directory_token_t *tok; time_t published_on; int i; smartlist_t *tokens = NULL; if (router_get_runningrouters_hash(str, digest)) { log_fn(LOG_WARN, "Unable to compute digest of directory"); goto err; } tokens = smartlist_create(); if (tokenize_string(str,str+strlen(str),tokens,1)) { log_fn(LOG_WARN, "Error tokenizing directory"); goto err; } if ((tok = find_first_by_keyword(tokens, _UNRECOGNIZED))) { log_fn(LOG_WARN, "Unrecognized keyword in \"%s\"; can't parse directory.", tok->args[0]); goto err; } tok = smartlist_get(tokens,0); if (tok->tp != K_NETWORK_STATUS) { log_fn(LOG_WARN, "Network-status starts with wrong token"); goto err; } if (!(tok = find_first_by_keyword(tokens, K_PUBLISHED))) { log_fn(LOG_WARN, "Missing published time on directory."); goto err; } tor_assert(tok->n_args == 1); if (parse_time(tok->args[0], &published_on) < 0) { goto err; } if (!(tok = find_first_by_keyword(tokens, K_RUNNING_ROUTERS))) { log_fn(LOG_WARN, "Missing running-routers line from directory."); goto err; } new_list = tor_malloc_zero(sizeof(running_routers_t)); new_list->published_on = published_on; new_list->running_routers = smartlist_create(); for (i=0;i<tok->n_args;++i) { smartlist_add(new_list->running_routers, tok->args[i]); } if (!(tok = find_first_by_keyword(tokens, K_DIRECTORY_SIGNATURE))) { log_fn(LOG_WARN, "Missing signature on directory"); goto err; } if (check_directory_signature(digest, tok, NULL)<0) { goto err; } goto done; err: running_routers_free(new_list); new_list = NULL; done: if (tokens) { SMARTLIST_FOREACH(tokens, directory_token_t *, tok, token_free(tok)); smartlist_free(tokens); } return new_list; } static int check_directory_signature(const char *digest, directory_token_t *tok, crypto_pk_env_t *pkey) { char signed_digest[PK_BYTES]; if (tok->n_args == 1) { routerinfo_t *r = router_get_by_nickname(tok->args[0]); log_fn(LOG_DEBUG, "Got directory signed by %s", tok->args[0]); if (r && r->is_trusted_dir) { pkey = r->identity_pkey; } else if (!r && pkey) { /* pkey provided for debugging purposes. */ } else if (!r) { log_fn(LOG_WARN, "Directory was signed by unrecognized server %s", tok->args[0]); return -1; } else if (r && !r->is_trusted_dir) { log_fn(LOG_WARN, "Directory was signed by non-trusted server %s", tok->args[0]); return -1; } } else if (tok->n_args > 1) { log_fn(LOG_WARN, "Too many arguments to directory-signature"); return -1; } if (strcmp(tok->object_type, "SIGNATURE") || tok->object_size != 128) { log_fn(LOG_WARN, "Bad object type or length on directory signature"); return -1; } if (pkey) { if (crypto_pk_public_checksig(pkey, tok->object_body, 128, signed_digest) != 20) { log_fn(LOG_WARN, "Error reading directory: invalid signature."); return -1; } log(LOG_DEBUG,"Signed directory hash starts %s", hex_str(signed_digest,4)); if (memcmp(digest, signed_digest, 20)) { log_fn(LOG_WARN, "Error reading directory: signature does not match."); return -1; } } else { /* XXXX008 freak out, unless testing. */ } return 0; } /** Given a string *<b>s</b> containing a concatenated * sequence of router descriptors, parses them and stores the result * in *<b>dest</b>. If good_nickname_lst is provided, then routers whose * nicknames are not listed are marked as nonrunning. Advances *s to * a point immediately following the last router entry. Returns 0 on * success and -1 on failure. */ int router_parse_list_from_string(const char **s, routerlist_t **dest, int n_good_nicknames, const char **good_nickname_list) { routerinfo_t *router; smartlist_t *routers; int rarray_len = 0; int i; const char *end; tor_assert(s && *s); routers = smartlist_create(); while (1) { *s = eat_whitespace(*s); /* Don't start parsing the rest of *s unless it contains a router. */ if (strncmp(*s, "router ", 7)!=0) break; if ((end = strstr(*s+1, "\nrouter "))) { end++; } else if ((end = strstr(*s+1, "\ndirectory-signature"))) { end++; } else { end = *s+strlen(*s); } router = router_parse_entry_from_string(*s, end); *s = end; if (!router) { log_fn(LOG_WARN, "Error reading router; skipping"); continue; } if (n_good_nicknames>=0) { router->is_running = 0; for (i = 0; i < n_good_nicknames; ++i) { if (router_nickname_matches(router, good_nickname_list[i])) { router->is_running = 1; break; } } } else { router->is_running = 1; /* start out assuming all dirservers are up */ } smartlist_add(routers, router); log_fn(LOG_DEBUG,"just added router #%d.",rarray_len); } if (*dest) routerlist_free(*dest); *dest = tor_malloc(sizeof(routerlist_t)); (*dest)->routers = routers; (*dest)->software_versions = NULL; return 0; } /** Helper function: reads a single router entry from *<b>s</b> ... * *<b>end</b>. Mallocs a new router and returns it if all goes well, else * returns NULL. */ routerinfo_t *router_parse_entry_from_string(const char *s, const char *end) { routerinfo_t *router = NULL; char signed_digest[128]; char digest[128]; smartlist_t *tokens = NULL, *exit_policy_tokens = NULL; directory_token_t *tok; int t; int ports_set, bw_set; if (!end) { end = s + strlen(s); } if (router_get_router_hash(s, digest) < 0) { log_fn(LOG_WARN, "Couldn't compute router hash."); return NULL; } tokens = smartlist_create(); if (tokenize_string(s,end,tokens,0)) { log_fn(LOG_WARN, "Error tokeninzing router descriptor."); goto err; } if (smartlist_len(tokens) < 2) { log_fn(LOG_WARN, "Impossibly short router descriptor."); goto err; } if ((tok = find_first_by_keyword(tokens, _UNRECOGNIZED))) { log_fn(LOG_WARN, "Unrecognized keyword in \"%s\"; skipping descriptor.", tok->args[0]); goto err; } tok = smartlist_get(tokens,0); if (tok->tp != K_ROUTER) { log_fn(LOG_WARN,"Entry does not start with \"router\""); goto err; } router = tor_malloc_zero(sizeof(routerinfo_t)); router->onion_pkey = router->identity_pkey = NULL; ports_set = bw_set = 0; if (tok->n_args == 2 || tok->n_args == 5 || tok->n_args == 6) { router->nickname = tor_strdup(tok->args[0]); if (strlen(router->nickname) > MAX_NICKNAME_LEN) { log_fn(LOG_WARN,"Router nickname too long."); goto err; } if (strspn(router->nickname, LEGAL_NICKNAME_CHARACTERS) != strlen(router->nickname)) { log_fn(LOG_WARN, "Router nickname contains illegal characters."); goto err; } router->address = tor_strdup(tok->args[1]); router->addr = 0; if (tok->n_args >= 5) { router->or_port = atoi(tok->args[2]); router->socks_port = atoi(tok->args[3]); router->dir_port = atoi(tok->args[4]); ports_set = 1; /* XXXX Remove this after everyone has moved to 0.0.6 */ if (tok->n_args == 6) { router->bandwidthrate = atoi(tok->args[5]); router->bandwidthburst = router->bandwidthrate * 10; bw_set = 1; } } } else { log_fn(LOG_WARN,"Wrong # of arguments to \"router\" (%d)",tok->n_args); goto err; } tok = find_first_by_keyword(tokens, K_PORTS); if (tok && ports_set) { log_fn(LOG_WARN,"Redundant ports line"); goto err; } else if (tok) { if (tok->n_args != 3) { log_fn(LOG_WARN,"Wrong # of arguments to \"ports\""); goto err; } router->or_port = atoi(tok->args[0]); router->socks_port = atoi(tok->args[1]); router->dir_port = atoi(tok->args[2]); ports_set = 1; } tok = find_first_by_keyword(tokens, K_DIRCACHEPORT); if (tok) { if (router->dir_port) log_fn(LOG_WARN,"Redundant dircacheport line"); if (tok->n_args != 1) { log_fn(LOG_WARN,"Wrong # of arguments to \"dircacheport\""); goto err; } router->dir_port = atoi(tok->args[0]); } tok = find_first_by_keyword(tokens, K_BANDWIDTH); if (tok && bw_set) { log_fn(LOG_WARN,"Redundant bandwidth line"); goto err; } else if (tok) { if (tok->n_args < 2) { log_fn(LOG_WARN,"Not enough arguments to \"bandwidth\""); goto err; } router->bandwidthrate = atoi(tok->args[0]); router->bandwidthburst = atoi(tok->args[1]); bw_set = 1; } if (!(tok = find_first_by_keyword(tokens, K_PUBLISHED))) { log_fn(LOG_WARN, "Missing published time"); goto err; } tor_assert(tok->n_args == 1); if (parse_time(tok->args[0], &router->published_on) < 0) goto err; if (!(tok = find_first_by_keyword(tokens, K_ONION_KEY))) { log_fn(LOG_WARN, "Missing onion key"); goto err; } /* XXX Check key length */ router->onion_pkey = tok->key; tok->key = NULL; /* Prevent free */ if ((tok = find_first_by_keyword(tokens, K_LINK_KEY))) { log_fn(LOG_INFO, "Skipping obsolete link-key"); } if (!(tok = find_first_by_keyword(tokens, K_SIGNING_KEY))) { log_fn(LOG_WARN, "Missing identity key"); goto err; } /* XXX Check key length */ router->identity_pkey = tok->key; tok->key = NULL; /* Prevent free */ if (crypto_pk_get_digest(router->identity_pkey,router->identity_digest)){ log_fn(LOG_WARN, "Couldn't calculate key digest"); goto err; } if ((tok = find_first_by_keyword(tokens, K_PLATFORM))) { router->platform = tor_strdup(tok->args[0]); } exit_policy_tokens = find_all_exitpolicy(tokens); SMARTLIST_FOREACH(exit_policy_tokens, directory_token_t *, t, if (router_add_exit_policy(router,t)<0) { log_fn(LOG_WARN,"Error in exit policy"); goto err;} ); if (!(tok = find_first_by_keyword(tokens, K_ROUTER_SIGNATURE))) { log_fn(LOG_WARN, "Missing router signature"); goto err; } if (strcmp(tok->object_type, "SIGNATURE") || tok->object_size != 128) { log_fn(LOG_WARN, "Bad object type or length on router signature"); goto err; } if ((t=crypto_pk_public_checksig(router->identity_pkey, tok->object_body, 128, signed_digest)) != 20) { log_fn(LOG_WARN, "Invalid signature %d",t); goto err; } if (memcmp(digest, signed_digest, 20)) { log_fn(LOG_WARN, "Mismatched signature"); goto err; } if (!ports_set) { log_fn(LOG_WARN,"No ports declared; failing."); goto err; } if (!bw_set) { log_fn(LOG_WARN,"No bandwidth declared; failing."); goto err; } if(!router->or_port) { log_fn(LOG_WARN,"or_port unreadable or 0. Failing."); goto err; } if (!router->bandwidthrate) { log_fn(LOG_WARN,"bandwidthrate unreadable or 0. Failing."); goto err; } if (!router->platform) { router->platform = tor_strdup("<unknown>"); } log_fn(LOG_DEBUG,"or_port %d, socks_port %d, dir_port %d, bandwidthrate %u, bandwidthburst %u.", router->or_port, router->socks_port, router->dir_port, (unsigned) router->bandwidthrate, (unsigned) router->bandwidthburst); goto done; return router; err: routerinfo_free(router); router = NULL; done: if (tokens) { SMARTLIST_FOREACH(tokens, directory_token_t *, tok, token_free(tok)); smartlist_free(tokens); } if (exit_policy_tokens) { smartlist_free(exit_policy_tokens); } return router; } /** Parse the exit policy in the string <b>s</b> and return it. */ struct exit_policy_t * router_parse_exit_policy_from_string(const char *s) { directory_token_t *tok = NULL; const char *cp; char *tmp; struct exit_policy_t *r; int len, idx; /* *s might not end with \n, so we need to extend it with one. */ len = strlen(s); cp = tmp = tor_malloc(len+2); for (idx = 0; idx < len; ++idx) { tmp[idx] = tolower(s[idx]); } tmp[len]='\n'; tmp[len+1]='\0'; tok = get_next_token(&cp, RTR_ONLY); if (tok->tp == _ERR) { log_fn(LOG_WARN, "Error reading exit policy: %s", tok->error); goto err; } if (tok->tp != K_ACCEPT && tok->tp != K_REJECT) { log_fn(LOG_WARN, "Expected 'accept' or 'reject'."); goto err; } /* Now that we've gotten an exit policy, add it to the router. */ r = router_parse_exit_policy(tok); goto done; err: r = NULL; done: free(tmp); token_free(tok); return r; } int router_add_exit_policy_from_string(routerinfo_t *router, const char *s) { struct exit_policy_t *newe, *tmpe; newe = router_parse_exit_policy_from_string(s); if (!newe) return -1; for (tmpe = router->exit_policy; tmpe; tmpe=tmpe->next) ; tmpe->next = newe; return 0; } static int router_add_exit_policy(routerinfo_t *router,directory_token_t *tok) { struct exit_policy_t *newe, **tmpe; newe = router_parse_exit_policy(tok); if (!newe) return -1; for (tmpe = &router->exit_policy; *tmpe; tmpe=&((*tmpe)->next)) ; *tmpe = newe; return 0; } /** Given a K_ACCEPT or K_REJECT token and a router, create a new exit_policy_t * corresponding to the token, and add it to <b>router</b> */ static struct exit_policy_t * router_parse_exit_policy(directory_token_t *tok) { struct exit_policy_t*newe; struct in_addr in; char *arg, *address, *mask, *port, *endptr; int bits; tor_assert(tok->tp == K_REJECT || tok->tp == K_ACCEPT); if (tok->n_args != 1) return NULL; arg = tok->args[0]; newe = tor_malloc_zero(sizeof(struct exit_policy_t)); newe->string = tor_malloc(8+strlen(arg)); if (tok->tp == K_REJECT) { strcpy(newe->string, "reject "); newe->policy_type = EXIT_POLICY_REJECT; } else { strcpy(newe->string, "accept "); newe->policy_type = EXIT_POLICY_ACCEPT; } strcat(newe->string, arg); /* can't overflow */ address = arg; mask = strchr(arg,'/'); port = strchr(mask?mask:arg,':'); /* Break 'arg' into separate strings. 'arg' was already strdup'd by * _router_get_next_token, so it's safe to modify. */ if (mask) *mask++ = 0; if (port) *port++ = 0; if (strcmp(address, "*") == 0) { newe->addr = 0; } else if (tor_inet_aton(address, &in) != 0) { newe->addr = ntohl(in.s_addr); } else { log_fn(LOG_WARN, "Malformed IP %s in exit policy; rejecting.", address); goto policy_read_failed; } if (!mask) { if (strcmp(address, "*") == 0) newe->msk = 0; else newe->msk = 0xFFFFFFFFu; } else { endptr = NULL; bits = (int) strtol(mask, &endptr, 10); if (!*endptr) { /* strtol handled the whole mask. */ newe->msk = ~((1<<(32-bits))-1); } else if (tor_inet_aton(mask, &in) != 0) { newe->msk = ntohl(in.s_addr); } else { log_fn(LOG_WARN, "Malformed mask %s on exit policy; rejecting.", mask); goto policy_read_failed; } } if (!port || strcmp(port, "*") == 0) { newe->prt_min = 0; newe->prt_max = 65535; } else { endptr = NULL; newe->prt_min = (uint16_t) strtol(port, &endptr, 10); if (*endptr == '-') { port = endptr+1; endptr = NULL; newe->prt_max = (uint16_t) strtol(port, &endptr, 10); if (*endptr) { log_fn(LOG_WARN, "Malformed port %s on exit policy; rejecting.", port); } } else if (*endptr) { log_fn(LOG_WARN, "Malformed port %s on exit policy; rejecting.", port); goto policy_read_failed; } else { newe->prt_max = newe->prt_min; } } in.s_addr = htonl(newe->addr); address = tor_strdup(inet_ntoa(in)); in.s_addr = htonl(newe->msk); log_fn(LOG_DEBUG,"%s %s/%s:%d-%d", newe->policy_type == EXIT_POLICY_REJECT ? "reject" : "accept", address, inet_ntoa(in), newe->prt_min, newe->prt_max); tor_free(address); newe->next = NULL; return newe; policy_read_failed: tor_assert(newe->string); log_fn(LOG_WARN,"Couldn't parse line '%s'. Dropping", newe->string); tor_free(newe->string); free(newe); return NULL; } /* * Low-level tokenizer for router descriptors and directories. */ /** Free all resources allocated for <b>tok</b> */ static void token_free(directory_token_t *tok) { int i; tor_assert(tok); if (tok->args) { for (i = 0; i < tok->n_args; ++i) { tor_free(tok->args[i]); } tor_free(tok->args); } tor_free(tok->object_type); tor_free(tok->object_body); if (tok->key) crypto_free_pk_env(tok->key); tor_free(tok); } /** Helper function: read the next token from *s, advance *s to the end * of the token, and return the parsed token. If 'where' is DIR_ONLY * or RTR_ONLY, reject all tokens of the wrong type. */ static directory_token_t * get_next_token(const char **s, where_syntax where) { const char *next, *obstart; int i, done, allocated, is_opt; directory_token_t *tok; arg_syntax a_syn; obj_syntax o_syn = NO_OBJ; #define RET_ERR(msg) \ do { if (tok) token_free(tok); \ tok = tor_malloc_zero(sizeof(directory_token_t));\ tok->tp = _ERR; \ tok->error = msg; \ goto done_tokenizing; } while (0) tok = tor_malloc_zero(sizeof(directory_token_t)); tok->tp = _ERR; *s = eat_whitespace(*s); if (!**s) { tok->tp = _EOF; return tok; } next = find_whitespace(*s); if (!next) { tok->error = "Unexpected EOF"; return tok; } /* It's a keyword... but which one? */ is_opt = !strncmp("opt", *s, next-*s); if (is_opt) { *s = eat_whitespace(next); next = NULL; if (**s) next = find_whitespace(*s); if (!**s || !next) { RET_ERR("opt without keyword"); } } for (i = 0; token_table[i].t ; ++i) { if (!strncmp(token_table[i].t, *s, next-*s)) { /* We've found the keyword. */ tok->tp = token_table[i].v; a_syn = token_table[i].s; o_syn = token_table[i].os; if (token_table[i].ws != ANY && token_table[i].ws != where) { if (where == DIR_ONLY) { RET_ERR("Found a router-only token in a directory section"); } else { RET_ERR("Found a directory-only token in a router descriptor"); } } if (a_syn == ARGS) { /* This keyword takes multiple arguments. */ i = 0; done = (*next == '\n'); allocated = 32; tok->args = tor_malloc(sizeof(char*)*32); *s = eat_whitespace_no_nl(next); while (**s != '\n' && !done) { next = find_whitespace(*s); if (*next == '\n') done = 1; if (i == allocated) { allocated *= 2; tok->args = tor_realloc(tok->args,sizeof(char*)*allocated); } tok->args[i++] = tor_strndup(*s,next-*s); *s = eat_whitespace_no_nl(next+1); } tok->n_args = i; } else if (a_syn == CONCAT_ARGS) { /* The keyword takes the line as a single argument */ *s = eat_whitespace_no_nl(next); next = strchr(*s, '\n'); if (!next) RET_ERR("Unexpected EOF"); tok->args = tor_malloc(sizeof(char*)); tok->args[0] = tor_strndup(*s,next-*s); tok->n_args = 1; *s = eat_whitespace_no_nl(next+1); } else { /* The keyword takes no arguments. */ tor_assert(a_syn == NO_ARGS); *s = eat_whitespace_no_nl(next); if (**s != '\n') { RET_ERR("Unexpected arguments"); } tok->n_args = 0; *s = eat_whitespace_no_nl(*s+1); } break; } } if (tok->tp == _ERR) { if (is_opt) { tok->tp = K_OPT; *s = eat_whitespace_no_nl(next); next = strchr(*s,'\n'); if (!next) RET_ERR("Unexpected EOF"); tok->args = tor_malloc(sizeof(char*)); tok->args[0] = tor_strndup(*s,next-*s); tok->n_args = 1; *s = eat_whitespace_no_nl(next+1); a_syn = OBJ_OK; } else { tok->tp = _UNRECOGNIZED; next = strchr(*s, '\n'); if (!next) { RET_ERR("Unexpected EOF"); } tok->args = tor_malloc(sizeof(char*)); tok->args[0] = tor_strndup(*s,next-*s); tok->n_args = 1; *s = next+1; o_syn = OBJ_OK; } } *s = eat_whitespace(*s); if (strncmp(*s, "-----BEGIN ", 11)) { goto done_tokenizing; } obstart = *s; *s += 11; /* length of "-----BEGIN ". */ next = strchr(*s, '\n'); if (next-*s < 6 || strncmp(next-5, "-----\n", 6)) { RET_ERR("Malformed object: bad begin line"); } tok->object_type = tor_strndup(*s, next-*s-5); *s = next+1; next = strstr(*s, "-----END "); if (!next) { RET_ERR("Malformed object: missing end line"); } if (!strcmp(tok->object_type, "RSA PUBLIC KEY")) { if (strncmp(next, "-----END RSA PUBLIC KEY-----\n", 29)) RET_ERR("Malformed object: mismatched end line"); next = strchr(next,'\n')+1; tok->key = crypto_new_pk_env(); if (crypto_pk_read_public_key_from_string(tok->key, obstart, next-obstart)) RET_ERR("Couldn't parse public key."); *s = next; } else { tok->object_body = tor_malloc(next-*s); /* really, this is too much RAM. */ i = base64_decode(tok->object_body, 256, *s, next-*s); if (i<0) { RET_ERR("Malformed object: bad base64-encoded data"); } tok->object_size = i; *s = next + 9; /* length of "-----END ". */ i = strlen(tok->object_type); if (strncmp(*s, tok->object_type, i) || strncmp(*s+i, "-----\n", 6)) { RET_ERR("Malformed object: mismatched end tag"); } *s += i+6; } switch(o_syn) { case NO_OBJ: if (tok->object_body) RET_ERR("Unexpected object for keyword"); if (tok->key) RET_ERR("Unexpected public key for keyword"); break; case NEED_OBJ: if (!tok->object_body) RET_ERR("Missing object for keyword"); break; case NEED_KEY: if (!tok->key) RET_ERR("Missing publid key for keyword"); break; case OBJ_OK: break; } done_tokenizing: #if 0 for (i = 0; token_table[i].t ; ++i) { if (token_table[i].v == tok->tp) { fputs(token_table[i].t, stdout); break; i = -1; } } if (i) { if (tok->tp == _UNRECOGNIZED) fputs("UNRECOGNIZED", stdout); if (tok->tp == _ERR) fputs("ERR",stdout); if (tok->tp == _EOF) fputs("EOF",stdout); if (tok->tp == _NIL) fputs("_NIL",stdout); } for(i = 0; i < tok->n_args; ++i) { fprintf(stdout," \"%s\"", tok->args[i]); } if (tok->error) { fprintf(stdout," *%s*", tok->error); } fputs("\n",stdout); #endif return tok; #undef RET_ERR } /** Read all tokens from a string between <b>start</b> and <b>end</b>, and add * them to <b>out</b>. If <b>is_dir</b> is true, reject all non-directory * tokens; else reject all non-routerdescriptor tokens. */ static int tokenize_string(const char *start, const char *end, smartlist_t *out, int is_dir) { const char **s; directory_token_t *tok = NULL; where_syntax where = is_dir ? DIR_ONLY : RTR_ONLY; s = &start; while (*s < end && (!tok || tok->tp != _EOF)) { tok = get_next_token(s, where); if (tok->tp == _ERR) { log_fn(LOG_WARN, "parse error: %s", tok->error); return -1; } smartlist_add(out, tok); *s = eat_whitespace(*s); } return 0; } /** Find the first token in <b>s</b> whose keyword is <b>keyword</b>; return * NULL if no such keyword is found. */ static directory_token_t * find_first_by_keyword(smartlist_t *s, directory_keyword keyword) { SMARTLIST_FOREACH(s, directory_token_t *, t, if (t->tp == keyword) return t); return NULL; } /** Return a newly allocated smartlist of all accept or reject tokens in * <b>s</b>. */ static smartlist_t * find_all_exitpolicy(smartlist_t *s) { smartlist_t *out = smartlist_create(); SMARTLIST_FOREACH(s, directory_token_t *, t, if (t->tp == K_ACCEPT || t->tp == K_REJECT) smartlist_add(out,t)); return out; } /** Compute the SHA digest of the substring of <b>s</b> taken from the first * occurrence of <b>start_str</b> through the first newline after the first * subsequent occurrence of <b>end_str</b>; store the 20-byte result in * <b>digest</b>; return 0 on success. * * If no such substring exists, return -1. */ static int router_get_hash_impl(const char *s, char *digest, const char *start_str, const char *end_str) { char *start, *end; start = strstr(s, start_str); if (!start) { log_fn(LOG_WARN,"couldn't find \"%s\"",start_str); return -1; } end = strstr(start+strlen(start_str), end_str); if (!end) { log_fn(LOG_WARN,"couldn't find \"%s\"",end_str); return -1; } end = strchr(end, '\n'); if (!end) { log_fn(LOG_WARN,"couldn't find EOL"); return -1; } ++end; if (crypto_digest(start, end-start, digest)) { log_fn(LOG_WARN,"couldn't compute digest"); return -1; } return 0; } /* Local Variables: mode:c indent-tabs-mode:nil c-basic-offset:2 End: */