diff options
Diffstat (limited to 'src/or/dns.c')
| -rw-r--r-- | src/or/dns.c | 90 |
1 files changed, 58 insertions, 32 deletions
diff --git a/src/or/dns.c b/src/or/dns.c index 4c24daed30..6b0043cdc5 100644 --- a/src/or/dns.c +++ b/src/or/dns.c @@ -2,7 +2,8 @@ * Copyright 2004-2005 Roger Dingledine, Nick Mathewson. */ /* See LICENSE for licensing information */ /* $Id$ */ -const char dns_c_id[] = "$Id$"; +const char dns_c_id[] = + "$Id$"; /** * \file dns.c @@ -12,7 +13,8 @@ const char dns_c_id[] = "$Id$"; * good, ubiquitous asynchronous DNS implementation.] **/ -/* See http://elvin.dstc.com/ListArchive/elvin-dev/archive/2001/09/msg00027.html +/* See + * http://elvin.dstc.com/ListArchive/elvin-dev/archive/2001/09/msg00027.html * for some approaches to asynchronous dns. We will want to switch once one of * them becomes more commonly available. */ @@ -58,7 +60,8 @@ typedef struct cached_resolve_t { HT_ENTRY(cached_resolve_t) node; char address[MAX_ADDRESSLEN]; /**< The hostname to be resolved. */ uint32_t addr; /**< IPv4 addr for <b>address</b>. */ - char state; /**< 0 is pending; 1 means answer is valid; 2 means resolve failed. */ + char state; /**< 0 is pending; 1 means answer is valid; 2 means resolve + * failed. */ #define CACHE_STATE_PENDING 0 #define CACHE_STATE_VALID 1 #define CACHE_STATE_FAILED 2 @@ -160,7 +163,8 @@ purge_expired_resolves(uint32_t now) debug(LD_EXIT,"Forgetting old cached resolve (address %s, expires %lu)", safe_str(resolve->address), (unsigned long)resolve->expire); if (resolve->state == CACHE_STATE_PENDING) { - debug(LD_EXIT,"Bug: Expiring a dns resolve ('%s') that's still pending. Forgot to cull it?", safe_str(resolve->address)); + debug(LD_EXIT,"Bug: Expiring a dns resolve ('%s') that's still pending." + " Forgot to cull it?", safe_str(resolve->address)); tor_fragile_assert(); } if (resolve->pending_connections) { @@ -181,7 +185,8 @@ purge_expired_resolves(uint32_t now) } oldest_cached_resolve = resolve->next; if (!oldest_cached_resolve) /* if there are no more, */ - newest_cached_resolve = NULL; /* then make sure the list's tail knows that too */ + newest_cached_resolve = NULL; /* then make sure the list's tail knows + * that too */ HT_REMOVE(cache_map, &cache_root, resolve); tor_free(resolve); } @@ -291,7 +296,8 @@ dns_resolve(connection_t *exitconn) pending_connection->conn = exitconn; pending_connection->next = resolve->pending_connections; resolve->pending_connections = pending_connection; - debug(LD_EXIT,"Connection (fd %d) waiting for pending DNS resolve of '%s'", + debug(LD_EXIT,"Connection (fd %d) waiting for pending DNS " + "resolve of '%s'", exitconn->s, safe_str(exitconn->address)); exitconn->state = EXIT_CONN_STATE_RESOLVING; return 0; @@ -349,7 +355,8 @@ assign_to_dnsworker(connection_t *exitconn) goto err; } - dnsconn = connection_get_by_type_state(CONN_TYPE_DNSWORKER, DNSWORKER_STATE_IDLE); + dnsconn = connection_get_by_type_state(CONN_TYPE_DNSWORKER, + DNSWORKER_STATE_IDLE); if (!dnsconn) { warn(LD_EXIT,"no idle dns workers. Failing."); @@ -374,7 +381,7 @@ assign_to_dnsworker(connection_t *exitconn) return 0; err: - dns_cancel_pending_resolve(exitconn->address); /* also sends end and frees! */ + dns_cancel_pending_resolve(exitconn->address); /* also sends end and frees */ return -1; } @@ -395,7 +402,8 @@ connection_dns_remove(connection_t *conn) resolve = HT_FIND(cache_map, &cache_root, &search); if (!resolve) { /* XXXX RD This *is* a bug, right? -NM */ - notice(LD_BUG,"Address '%s' is not pending. Dropping.", safe_str(conn->address)); + notice(LD_BUG, "Address '%s' is not pending. Dropping.", + safe_str(conn->address)); return; } @@ -407,7 +415,8 @@ connection_dns_remove(connection_t *conn) if (pend->conn == conn) { resolve->pending_connections = pend->next; tor_free(pend); - debug(LD_EXIT, "First connection (fd %d) no longer waiting for resolve of '%s'", + debug(LD_EXIT, "First connection (fd %d) no longer waiting for resolve " + "of '%s'", conn->s, safe_str(conn->address)); return; } else { @@ -416,7 +425,8 @@ connection_dns_remove(connection_t *conn) victim = pend->next; pend->next = victim->next; tor_free(victim); - debug(LD_EXIT, "Connection (fd %d) no longer waiting for resolve of '%s'", + debug(LD_EXIT, "Connection (fd %d) no longer waiting for resolve " + "of '%s'", conn->s, safe_str(conn->address)); return; /* more are pending */ } @@ -529,8 +539,10 @@ dns_purge_resolve(cached_resolve_t *resolve) newest_cached_resolve = NULL; } else { /* FFFF make it a doubly linked list if this becomes too slow */ - for (tmp=oldest_cached_resolve; tmp && tmp->next != resolve; tmp=tmp->next) ; - tor_assert(tmp); /* it's got to be in the list, or we screwed up somewhere else */ + for (tmp=oldest_cached_resolve; tmp && tmp->next != resolve; tmp=tmp->next) + ; + tor_assert(tmp); /* it's got to be in the list, or we screwed up somewhere + * else */ tmp->next = resolve->next; /* unlink it */ if (newest_cached_resolve == resolve) @@ -605,7 +617,8 @@ dns_found_answer(char *address, uint32_t addr, char outcome) /* prevent double-remove. */ pendconn->state = EXIT_CONN_STATE_RESOLVEFAILED; if (pendconn->purpose == EXIT_PURPOSE_CONNECT) { - connection_edge_end(pendconn, END_STREAM_REASON_RESOLVEFAILED, pendconn->cpath_layer); + connection_edge_end(pendconn, END_STREAM_REASON_RESOLVEFAILED, + pendconn->cpath_layer); /* This detach must happen after we send the end cell. */ circuit_detach_stream(circuit_get_by_edge_conn(pendconn), pendconn); } else { @@ -694,7 +707,8 @@ connection_dns_process_inbuf(connection_t *conn) tor_assert(conn->type == CONN_TYPE_DNSWORKER); if (conn->state != DNSWORKER_STATE_BUSY && buf_datalen(conn->inbuf)) { - warn(LD_BUG,"Bug: read data (%d bytes) from an idle dns worker (fd %d, address '%s'). Please report.", + warn(LD_BUG,"Bug: read data (%d bytes) from an idle dns worker (fd %d, " + "address '%s'). Please report.", (int)buf_datalen(conn->inbuf), conn->s, safe_str(conn->address)); tor_fragile_assert(); @@ -781,11 +795,13 @@ dnsworker_main(void *data) int fd; int result; - /* log_fn(LOG_NOTICE,"After spawn: fdarray @%d has %d:%d", (int)fdarray, fdarray[0],fdarray[1]); */ + /* log_fn(LOG_NOTICE,"After spawn: fdarray @%d has %d:%d", (int)fdarray, + * fdarray[0],fdarray[1]); */ fd = fdarray[1]; /* this side is ours */ #ifndef TOR_IS_MULTITHREADED - tor_close_socket(fdarray[0]); /* this is the side of the socketpair the parent uses */ + tor_close_socket(fdarray[0]); /* this is the side of the socketpair the + * parent uses */ tor_free_all(1); /* so the child doesn't hold the parent's fd's open */ handle_signals(0); /* ignore interrupts from the keyboard, etc */ #endif @@ -796,10 +812,13 @@ dnsworker_main(void *data) if ((r = recv(fd, &address_len, 1, 0)) != 1) { if (r == 0) { - info(LD_EXIT,"DNS worker exiting because Tor process closed connection (either pruned idle dnsworker or died)."); + info(LD_EXIT,"DNS worker exiting because Tor process closed " + "connection (either pruned idle dnsworker or died)."); } else { - info(LD_EXIT,"DNS worker exiting because of error on connection to Tor process."); - info(LD_EXIT,"(Error on %d was %s)", fd, tor_socket_strerror(tor_socket_errno(fd))); + info(LD_EXIT,"DNS worker exiting because of error on connection " + "to Tor process."); + info(LD_EXIT,"(Error on %d was %s)", fd, + tor_socket_strerror(tor_socket_errno(fd))); } tor_close_socket(fd); crypto_thread_cleanup(); @@ -821,11 +840,13 @@ dnsworker_main(void *data) switch (result) { case 1: /* XXX result can never be 1, because we set it to -1 above on error */ - info(LD_NET,"Could not resolve dest addr %s (transient).",safe_str(address)); + info(LD_NET,"Could not resolve dest addr %s (transient).", + safe_str(address)); answer[0] = DNS_RESOLVE_FAILED_TRANSIENT; break; case -1: - info(LD_NET,"Could not resolve dest addr %s (permanent).",safe_str(address)); + info(LD_NET,"Could not resolve dest addr %s (permanent).", + safe_str(address)); answer[0] = DNS_RESOLVE_FAILED_PERMANENT; break; case 0: @@ -856,18 +877,21 @@ spawn_dnsworker(void) fdarray = tor_malloc(sizeof(int)*2); if ((err = tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fdarray)) < 0) { - warn(LD_NET, "Couldn't construct socketpair: %s", tor_socket_strerror(-err)); + warn(LD_NET, "Couldn't construct socketpair: %s", + tor_socket_strerror(-err)); tor_free(fdarray); return -1; } - /* log_fn(LOG_NOTICE,"Before spawn: fdarray @%d has %d:%d", (int)fdarray, fdarray[0],fdarray[1]); */ + /* log_fn(LOG_NOTICE,"Before spawn: fdarray @%d has %d:%d", + (int)fdarray, fdarray[0],fdarray[1]); */ - fd = fdarray[0]; /* We copy this out here, since dnsworker_main may free fdarray */ + fd = fdarray[0]; /* We copy this out here, since dnsworker_main may free + * fdarray */ spawn_func(dnsworker_main, (void*)fdarray); debug(LD_EXIT,"just spawned a worker."); #ifndef TOR_IS_MULTITHREADED - tor_close_socket(fdarray[1]); /* we don't need the worker's side of the pipe */ + tor_close_socket(fdarray[1]); /* don't need the worker's side of the pipe */ tor_free(fdarray); #endif @@ -903,12 +927,13 @@ spawn_enough_dnsworkers(void) connection_t *dnsconn; /* XXX This may not be the best strategy. Maybe we should queue pending - * requests until the old ones finish or time out: otherwise, if - * the connection requests come fast enough, we never get any DNS done. -NM + * requests until the old ones finish or time out: otherwise, if the + * connection requests come fast enough, we never get any DNS done. -NM + * * XXX But if we queue them, then the adversary can pile even more - * queries onto us, blocking legitimate requests for even longer. - * Maybe we should compromise and only kill if it's been at it for - * more than, e.g., 2 seconds. -RD + * queries onto us, blocking legitimate requests for even longer. Maybe + * we should compromise and only kill if it's been at it for more than, + * e.g., 2 seconds. -RD */ if (num_dnsworkers_busy == MAX_DNSWORKERS) { /* We always want at least one worker idle. @@ -944,7 +969,8 @@ spawn_enough_dnsworkers(void) /* cull excess workers */ info(LD_EXIT,"%d of %d dnsworkers are idle. Killing one.", num_dnsworkers-num_dnsworkers_busy, num_dnsworkers); - dnsconn = connection_get_by_type_state(CONN_TYPE_DNSWORKER, DNSWORKER_STATE_IDLE); + dnsconn = connection_get_by_type_state(CONN_TYPE_DNSWORKER, + DNSWORKER_STATE_IDLE); tor_assert(dnsconn); connection_mark_for_close(dnsconn); num_dnsworkers--; |