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f241fdfc73
tor/src/or/routerlist.c
Roger Dingledine f241fdfc73 there is yet another dns-pending-conn-clobbering bug 
somewhere


svn:r1354
2004-03-28 04:54:36 +00:00

1464 lines
41 KiB
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/* Copyright 2001-2003 Roger Dingledine, Matej Pfajfar. */
/* See LICENSE for licensing information */
/* $Id$ */
#define _GNU_SOURCE
/* XXX this is required on rh7 to make strptime not complain. how bad
* is this for portability?
*/
#include "or.h"
/****************************************************************************/
static routerlist_t *routerlist = NULL; /* router array */
extern or_options_t options; /* command-line and config-file options */
/****************************************************************************/
/* Enumeration of possible token types. The ones starting with K_ correspond
* to directory 'keywords'. _SIGNATURE and _PUBLIC_KEY are self-explanatory.
* _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,
K_ROUTER_SIGNATURE,
K_PUBLISHED,
K_RUNNING_ROUTERS,
K_PLATFORM,
K_OPT,
K_BANDWIDTH,
K_PORTS,
_UNRECOGNIZED,
_ERR,
_EOF,
_NIL
} directory_keyword;
typedef struct directory_token_t {
directory_keyword tp; /* Type of the token. */
int n_args;
char **args;
char *object_type;
int object_size;
char *object_body;
crypto_pk_env_t *key; /* For public keys only. */
char *error; /* For _ERR tokens only. */
} directory_token_t;
/* ********************************************************************** */
/* Every keyword takes either... */
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;
typedef enum {
NO_OBJ,
NEED_OBJ,
NEED_KEY,
OBJ_OK,
} obj_syntax;
typedef enum {
ANY = 0,
DIR_ONLY,
RTR_ONLY,
} where_syntax;
/* Table mapping keywods 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, NO_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 },
{ "published", K_PUBLISHED, CONCAT_ARGS, NO_OBJ, ANY },
{ "running-routers", K_RUNNING_ROUTERS, ARGS, NO_OBJ, DIR_ONLY },
{ "platform", K_PLATFORM, CONCAT_ARGS, NO_OBJ, RTR_ONLY },
{ "ports", K_PORTS, ARGS, NO_OBJ, RTR_ONLY },
{ "bandwidth", K_BANDWIDTH, ARGS, NO_OBJ, RTR_ONLY },
{ "opt", K_OPT, CONCAT_ARGS, OBJ_OK, ANY },
{ NULL, -1 }
};
/* ********************************************************************** */
/* static function prototypes */
static routerinfo_t *
router_pick_directory_server_impl(void);
static int
router_get_list_from_string_impl(const char **s, routerlist_t **dest,
int n_good_nicknames,
const char **good_nickname_lst);
static int
router_get_routerlist_from_directory_impl(const char *s, routerlist_t **dest,
crypto_pk_env_t *pkey);
static int
router_add_exit_policy(routerinfo_t *router, directory_token_t *tok);
static int
router_resolve_routerlist(routerlist_t *dir);
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);
/****************************************************************************/
extern int has_fetched_directory;
/* try to find a running dirserver. if there are no dirservers
* in our routerlist, reload the routerlist and try again. */
routerinfo_t *router_pick_directory_server(void) {
routerinfo_t *choice;
choice = router_pick_directory_server_impl();
if(!choice) {
log_fn(LOG_WARN,"No dirservers known. Reloading and trying again.");
has_fetched_directory=0; /* reset it */
if(options.RouterFile) {
if(router_set_routerlist_from_file(options.RouterFile) < 0)
return NULL;
} else {
if(config_assign_default_dirservers() < 0)
return NULL;
}
/* give it another try */
choice = router_pick_directory_server_impl();
}
return choice;
}
/* pick a random running router with a positive dir_port */
static routerinfo_t *router_pick_directory_server_impl(void) {
int i;
routerinfo_t *router, *dirserver=NULL;
smartlist_t *sl;
if(!routerlist)
return NULL;
sl = smartlist_create(MAX_ROUTERS_IN_DIR);
for(i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if(router->dir_port > 0 && router->is_running)
smartlist_add(sl, router);
}
router = smartlist_choose(sl);
smartlist_free(sl);
if(router)
return router;
log_fn(LOG_INFO,"No dirservers are reachable. Trying them all again.");
/* no running dir servers found? go through and mark them all as up,
* and we'll cycle through the list again. */
for(i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if(router->dir_port > 0) {
router->is_running = 1;
dirserver = router;
}
}
if(!dirserver)
log_fn(LOG_WARN,"No dirservers in directory! Returning NULL.");
return dirserver;
}
void router_add_running_routers_to_smartlist(smartlist_t *sl) {
routerinfo_t *router;
int i;
if(!routerlist)
return;
for(i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if(router->is_running &&
(!options.ORPort ||
connection_twin_get_by_addr_port(router->addr, router->or_port) ))
smartlist_add(sl, router);
}
}
routerinfo_t *router_get_by_addr_port(uint32_t addr, uint16_t port) {
int i;
routerinfo_t *router;
assert(routerlist);
for(i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if ((router->addr == addr) && (router->or_port == port))
return router;
}
return NULL;
}
routerinfo_t *router_get_by_link_pk(crypto_pk_env_t *pk)
{
int i;
routerinfo_t *router;
assert(routerlist);
for(i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if (0 == crypto_pk_cmp_keys(router->link_pkey, pk))
return router;
}
return NULL;
}
routerinfo_t *router_get_by_nickname(char *nickname)
{
int i;
routerinfo_t *router;
assert(routerlist);
for(i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if (0 == strcmp(router->nickname, nickname))
return router;
}
return NULL;
}
/* a way to access routerlist outside this file */
void router_get_routerlist(routerlist_t **prouterlist) {
*prouterlist = routerlist;
}
/* delete a router from memory */
void routerinfo_free(routerinfo_t *router)
{
struct exit_policy_t *e;
if (!router)
return;
tor_free(router->address);
tor_free(router->nickname);
if (router->onion_pkey)
crypto_free_pk_env(router->onion_pkey);
if (router->link_pkey)
crypto_free_pk_env(router->link_pkey);
if (router->identity_pkey)
crypto_free_pk_env(router->identity_pkey);
while (router->exit_policy) {
e = router->exit_policy;
router->exit_policy = e->next;
tor_free(e->string);
free(e);
}
free(router);
}
static void routerlist_free(routerlist_t *rl)
{
int i;
for (i = 0; i < rl->n_routers; ++i)
routerinfo_free(rl->routers[i]);
tor_free(rl->routers);
tor_free(rl->software_versions);
free(rl);
}
void router_mark_as_down(char *nickname) {
routerinfo_t *router = router_get_by_nickname(nickname);
if(!router) /* we don't seem to know about him in the first place */
return;
log_fn(LOG_DEBUG,"Marking %s as down.",router->nickname);
router->is_running = 0;
}
/* ------------------------------------------------------------ */
/* Replace the current router list with the one stored in 'routerfile'. */
int router_set_routerlist_from_file(char *routerfile)
{
char *string;
string = read_file_to_str(routerfile);
if(!string) {
log_fn(LOG_WARN,"Failed to load routerfile %s.",routerfile);
return -1;
}
if(router_set_routerlist_from_string(string) < 0) {
log_fn(LOG_WARN,"The routerfile itself was corrupt.");
free(string);
return -1;
}
free(string);
return 0;
}
/* Helper function: read routerinfo elements from s, and throw out the
* ones that don't parse and resolve. Replace the current
* routerlist. */
int router_set_routerlist_from_string(const char *s)
{
if (router_get_list_from_string_impl(&s, &routerlist, -1, NULL)) {
log(LOG_WARN, "Error parsing router file");
return -1;
}
if (router_resolve_routerlist(routerlist)) {
log(LOG_WARN, "Error resolving routerlist");
return -1;
}
return 0;
}
/* Set 'digest' to the SHA-1 digest of the hash of the directory in 's'.
* 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 'digest' to the SHA-1 digest of the hash of the first router in 's'.
* 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");
}
/* return 1 if myversion is in versionlist. Else return 0.
* (versionlist contains a comma-separated list of versions.) */
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;
}
}
/* Replace the current routerlist with the routers stored in the directory
* 's'. If pkey is provided, make sure that 's' is signed with pkey. */
int router_set_routerlist_from_directory(const char *s, crypto_pk_env_t *pkey)
{
if (router_get_routerlist_from_directory_impl(s, &routerlist, pkey)) {
log_fn(LOG_WARN, "Couldn't parse directory.");
return -1;
}
if (router_resolve_routerlist(routerlist)) {
log_fn(LOG_WARN, "Error resolving routerlist");
return -1;
}
if (is_recommended_version(VERSION,
routerlist->software_versions) < 0) {
log(options.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(routerlist->software_versions,',') ? "one of " : "",
routerlist->software_versions);
if(options.IgnoreVersion) {
log(LOG_WARN, "IgnoreVersion is set. If it breaks, we told you so.");
} else {
fflush(0);
exit(0);
}
}
return 0;
}
/* Helper function: resolve the hostname for 'router' */
static int
router_resolve(routerinfo_t *router)
{
struct hostent *rent;
rent = (struct hostent *)gethostbyname(router->address);
if (!rent) {
log_fn(LOG_WARN,"Could not get address for router %s (%s).",
router->address, router->nickname);
return -1;
}
assert(rent->h_length == 4);
memcpy(&router->addr, rent->h_addr,rent->h_length);
router->addr = ntohl(router->addr); /* get it back into host order */
return 0;
}
/* Helper function: resolve every router in rl. */
static int
router_resolve_routerlist(routerlist_t *rl)
{
int i, max, remove;
if (!rl)
rl = routerlist;
max = rl->n_routers;
for (i = 0; i < max; ++i) {
remove = 0;
if (router_resolve(rl->routers[i])) {
log_fn(LOG_WARN, "Couldn't resolve router %s; not using",
rl->routers[i]->address);
remove = 1;
} else if (options.Nickname &&
!strcmp(rl->routers[i]->nickname, options.Nickname)) {
remove = 1;
}
if (remove) {
routerinfo_free(rl->routers[i]);
rl->routers[i] = rl->routers[--max];
--rl->n_routers;
--i;
}
}
return 0;
}
/* Addr is 0 for "IP unknown".
*
* Returns -1 for 'rejected', 0 for accepted, 1 for 'maybe' (since IP is
* unknown.
*/
int router_compare_addr_to_exit_policy(uint32_t addr, uint16_t port,
struct exit_policy_t *policy)
{
int maybe_reject = 0;
int maybe_accept = 0;
int match = 0;
int maybe = 0;
struct in_addr in;
struct exit_policy_t *tmpe;
for(tmpe=policy; tmpe; tmpe=tmpe->next) {
// log_fn(LOG_DEBUG,"Considering exit policy %s", tmpe->string);
maybe = 0;
if (!addr) {
/* Address is unknown. */
if (port >= tmpe->prt_min && port <= tmpe->prt_max) {
/* The port definitely matches. */
if (tmpe->msk == 0) {
match = 1;
} else {
maybe = 1;
}
} else if (!port) {
/* The port maybe matches. */
maybe = 1;
}
} else {
/* Address is known */
if ((addr & tmpe->msk) == (tmpe->addr & tmpe->msk)) {
if (port >= tmpe->prt_min && port <= tmpe->prt_max) {
/* Exact match for the policy */
match = 1;
} else if (!port) {
maybe = 1;
}
}
}
if (maybe) {
if (tmpe->policy_type == EXIT_POLICY_REJECT)
maybe_reject = 1;
else
maybe_accept = 1;
}
if (match) {
in.s_addr = htonl(addr);
log_fn(LOG_DEBUG,"Address %s:%d matches exit policy '%s'",
inet_ntoa(in), port, tmpe->string);
if(tmpe->policy_type == EXIT_POLICY_ACCEPT) {
/* If we already hit a clause that might trigger a 'reject', than we
* can't be sure of this certain 'accept'.*/
return maybe_reject ? ADDR_POLICY_UNKNOWN : ADDR_POLICY_ACCEPTED;
} else {
return maybe_accept ? ADDR_POLICY_UNKNOWN : ADDR_POLICY_REJECTED;
}
}
}
/* accept all by default. */
return maybe_reject ? ADDR_POLICY_UNKNOWN : ADDR_POLICY_ACCEPTED;
}
/* return 1 if all running routers will reject addr:port, return 0 if
any might accept it. */
int router_exit_policy_all_routers_reject(uint32_t addr, uint16_t port) {
int i;
routerinfo_t *router;
for (i=0;i<routerlist->n_routers;i++) {
router = routerlist->routers[i];
if (router->is_running && router_compare_addr_to_exit_policy(
addr, port, router->exit_policy) != ADDR_POLICY_REJECTED)
return 0; /* this one could be ok. good enough. */
}
return 1; /* all will reject. */
}
int router_exit_policy_rejects_all(routerinfo_t *router) {
return router_compare_addr_to_exit_policy(0, 0, router->exit_policy)
== ADDR_POLICY_REJECTED;
}
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;
}
/* Helper function: parse a directory from 's' and, when done, store the
* resulting routerlist in *dest, freeing the old value if necessary.
* If pkey is provided, we check the directory signature with pkey.
*/
static int
router_get_routerlist_from_directory_impl(const char *str,
routerlist_t **dest,
crypto_pk_env_t *pkey)
{
directory_token_t *tok;
char digest[20];
char signed_digest[128];
routerlist_t *new_dir = NULL;
char *versions = NULL;
time_t published_on;
char *good_nickname_lst[1024];
int n_good_nicknames = 0;
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 %02x:%02x:%02x:%02x",
((int)digest[0])&0xff,((int)digest[1])&0xff,
((int)digest[2])&0xff,((int)digest[3])&0xff);
if ((end = strstr(str,"\nrouter "))) {
++end;
} else if ((end = strstr(str, "\ndirectory-signature"))) {
++end;
} else {
end = str + strlen(str);
}
tokens = smartlist_create(128);
if (tokenize_string(str,end,tokens,1)) {
log_fn(LOG_WARN, "Error tokenizing directory"); goto err;
}
if (tokens->num_used < 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 = (directory_token_t*)tokens->list[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;
}
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_get_list_from_string_impl(&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;
for (i = 0; i < tokens->num_used; ++i) {
token_free((directory_token_t*)tokens->list[i]);
}
smartlist_free(tokens);
tokens = smartlist_create(128);
if (tokenize_string(str,str+strlen(str),tokens,1)<0) {
log_fn(LOG_WARN, "Error tokenizing signature"); goto err;
}
if (tokens->num_used != 1 ||
((directory_token_t*)tokens->list[0])->tp != K_DIRECTORY_SIGNATURE){
log_fn(LOG_WARN,"Expected a single directory signature"); goto err;
}
tok = (directory_token_t*)tokens->list[0];
if (strcmp(tok->object_type, "SIGNATURE") || tok->object_size != 128) {
log_fn(LOG_WARN, "Bad object type or length on directory signature");
goto err;
}
if (pkey) {
if (crypto_pk_public_checksig(pkey, tok->object_body, 128, signed_digest)
!= 20) {
log_fn(LOG_WARN, "Error reading directory: invalid signature.");
goto err;
}
log(LOG_DEBUG,"Signed directory hash starts %02x:%02x:%02x:%02x",
((int)signed_digest[0])&0xff,((int)signed_digest[1])&0xff,
((int)signed_digest[2])&0xff,((int)signed_digest[3])&0xff);
if (memcmp(digest, signed_digest, 20)) {
log_fn(LOG_WARN, "Error reading directory: signature does not match.");
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) {
for (i = 0; i < tokens->num_used; ++i) {
token_free((directory_token_t*)tokens->list[i]);
}
smartlist_free(tokens);
}
return r;
}
/* Helper function: Given a string *s containing a concatenated
* sequence of router descriptors, parses them and stores the result
* in *dest. 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.
*/
static int
router_get_list_from_string_impl(const char **s, routerlist_t **dest,
int n_good_nicknames,
const char **good_nickname_lst)
{
routerinfo_t *router;
routerinfo_t **rarray;
int rarray_len = 0;
int i;
const char *end;
assert(s && *s);
rarray = (routerinfo_t **)
tor_malloc((sizeof(routerinfo_t *))*MAX_ROUTERS_IN_DIR);
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_get_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 (0==strcasecmp(good_nickname_lst[i], router->nickname)) {
router->is_running = 1;
break;
}
}
} else {
router->is_running = 1; /* start out assuming all dirservers are up */
}
rarray[rarray_len++] = router;
log_fn(LOG_DEBUG,"just added router #%d.",rarray_len);
}
if (*dest)
routerlist_free(*dest);
*dest = (routerlist_t *)tor_malloc(sizeof(routerlist_t));
(*dest)->routers = rarray;
(*dest)->n_routers = rarray_len;
(*dest)->software_versions = NULL;
return 0;
}
/* Helper function: reads a single router entry from *s, and advances
* *s so it points to just after the router it just read.
* mallocs a new router and returns it if all goes well, else returns
* NULL.
*
* DOCDOC
*/
routerinfo_t *router_get_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, i;
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(128);
if (tokenize_string(s,end,tokens,0)) {
log_fn(LOG_WARN, "Error tokeninzing router descriptor."); goto err;
}
if (tokens->num_used < 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 = (directory_token_t*)tokens->list[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 = router->link_pkey = NULL;
ports_set = bw_set = 0;
if (tok->n_args == 2 || 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 == 6) {
router->or_port = atoi(tok->args[2]);
router->socks_port = atoi(tok->args[3]);
router->dir_port = atoi(tok->args[4]);
router->bandwidthrate = atoi(tok->args[5]);
ports_set = bw_set = 1;
}
} else {
log_fn(LOG_WARN,"Wrong # of arguments to \"router\"");
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_BANDWIDTH);
if (tok && bw_set) {
log_fn(LOG_WARN,"Redundant bandwidth line");
goto err;
} else if (tok) {
if (tok->n_args < 1) {
log_fn(LOG_WARN,"Not enough arguments to \"bandwidth\"");
goto err;
}
router->bandwidthrate = atoi(tok->args[0]);
bw_set = 1;
}
if (!(tok = find_first_by_keyword(tokens, K_PUBLISHED))) {
log_fn(LOG_WARN, "Missing published time"); goto err;
}
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_WARN, "Missing onion key"); goto err;
}
/* XXX Check key length */
router->link_pkey = tok->key;
tok->key = NULL; /* Prevent free */
if (!(tok = find_first_by_keyword(tokens, K_SIGNING_KEY))) {
log_fn(LOG_WARN, "Missing onion key"); goto err;
}
/* XXX Check key length */
router->identity_pkey = tok->key;
tok->key = NULL; /* Prevent free */
exit_policy_tokens = find_all_exitpolicy(tokens);
for (i = 0; i < exit_policy_tokens->num_used; ++i) {
if (router_add_exit_policy(router,
(directory_token_t*)exit_policy_tokens->list[i])<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 XXXBC
router->bandwidthburst = atoi(ARGS[6]);
if (!router->bandwidthburst) {
log_fn(LOG_WARN,"bandwidthburst unreadable or 0. Failing.");
goto err;
}
#else
router->bandwidthburst = 10*router->bandwidthrate;
#endif
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) {
for (i = 0; i < tokens->num_used; ++i) {
token_free((directory_token_t*)tokens->list[i]);
}
smartlist_free(tokens);
}
if (exit_policy_tokens) {
smartlist_free(exit_policy_tokens);
}
return router;
}
/* Parse the exit policy in the string 's' and add it to 'router'.
*/
int
router_add_exit_policy_from_string(routerinfo_t *router, const char *s)
{
directory_token_t *tok = NULL;
const char *cp;
char *tmp;
int 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_add_exit_policy(router, tok);
goto done;
err:
r = -1;
done:
free(tmp);
token_free(tok);
return r;
}
/* 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 'router' */
static int
router_add_exit_policy(routerinfo_t *router, directory_token_t *tok) {
struct exit_policy_t *tmpe, *newe;
struct in_addr in;
char *arg, *address, *mask, *port, *endptr;
int bits;
assert(tok->tp == K_REJECT || tok->tp == K_ACCEPT);
if (tok->n_args != 1)
return -1;
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);
/* now link newe onto the end of exit_policy */
if(!router->exit_policy) {
router->exit_policy = newe;
return 0;
}
for(tmpe=router->exit_policy; tmpe->next; tmpe=tmpe->next) ;
tmpe->next = newe;
return 0;
policy_read_failed:
assert(newe->string);
log_fn(LOG_WARN,"Couldn't parse line '%s'. Dropping", newe->string);
tor_free(newe->string);
free(newe);
return -1;
}
/* ------------------------------------------------------------ */
/* Tokenizer for router descriptors and directories. */
/* Free any malloced resources allocated for a token. Does not free
* the token itself.
*/
static void
token_free(directory_token_t *tok)
{
int i;
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, and stores it into a new
* directory token *tok.
*/
static directory_token_t *
get_next_token(const char **s, where_syntax where) {
const char *next, *obstart;
int i, done, allocated;
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? */
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 = (char**)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 = (char**)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 = (char**) 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. */
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) {
tok->tp = _UNRECOGNIZED;
next = strchr(*s, '\n');
if (!next) {
RET_ERR("Unexpected EOF");
}
tok->args = (char**) 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(CRYPTO_PK_RSA);
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
}
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;
}
static directory_token_t *
find_first_by_keyword(smartlist_t *s, directory_keyword keyword)
{
int i;
directory_token_t *tok;
for (i = 0; i < s->num_used; ++i) {
tok = (directory_token_t*) s->list[i];
if (tok->tp == keyword) {
return tok;
}
}
return NULL;
}
static smartlist_t *
find_all_exitpolicy(smartlist_t *s)
{
int i;
directory_token_t *tok;
smartlist_t *out = smartlist_create(s->num_used);
for (i = 0; i < s->num_used; ++i) {
tok = (directory_token_t*) s->list[i];
if (tok->tp == K_ACCEPT || tok->tp == K_REJECT) {
smartlist_add(out,tok);
}
}
return out;
}
/* Compute the SHA digest of the substring of s taken from the first
* occurrence of start_str through the first newline after the first
* subsequent occurrence of end_str; store the 20-byte result in 'digest';
* 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_SHA_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:
*/
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