/* * AF_INET/AF_INET6 SOCK_STREAM protocol layer (tcp) * * Copyright 2000-2008 Willy Tarreau * * 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. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_HAP_CTTPROXY #include #endif static int tcp_bind_listeners(struct protocol *proto); /* Note: must not be declared as its list will be overwritten */ static struct protocol proto_tcpv4 = { .name = "tcpv4", .sock_domain = AF_INET, .sock_type = SOCK_STREAM, .sock_prot = IPPROTO_TCP, .sock_family = AF_INET, .sock_addrlen = sizeof(struct sockaddr_in), .l3_addrlen = 32/8, .read = &stream_sock_read, .write = &stream_sock_write, .bind_all = tcp_bind_listeners, .unbind_all = unbind_all_listeners, .enable_all = enable_all_listeners, .listeners = LIST_HEAD_INIT(proto_tcpv4.listeners), .nb_listeners = 0, }; /* Note: must not be declared as its list will be overwritten */ static struct protocol proto_tcpv6 = { .name = "tcpv6", .sock_domain = AF_INET6, .sock_type = SOCK_STREAM, .sock_prot = IPPROTO_TCP, .sock_family = AF_INET6, .sock_addrlen = sizeof(struct sockaddr_in6), .l3_addrlen = 128/8, .read = &stream_sock_read, .write = &stream_sock_write, .bind_all = tcp_bind_listeners, .unbind_all = unbind_all_listeners, .enable_all = enable_all_listeners, .listeners = LIST_HEAD_INIT(proto_tcpv6.listeners), .nb_listeners = 0, }; /* Binds ipv4 address to socket , unless is set, in which * case we try to bind . is a 2-bit field consisting of : * - 0 : ignore remote address (may even be a NULL pointer) * - 1 : use provided address * - 2 : use provided port * - 3 : use both * * The function supports multiple foreign binding methods : * - linux_tproxy: we directly bind to the foreign address * - cttproxy: we bind to a local address then nat. * The second one can be used as a fallback for the first one. * This function returns 0 when everything's OK, 1 if it could not bind, to the * local address, 2 if it could not bind to the foreign address. */ int tcpv4_bind_socket(int fd, int flags, struct sockaddr_in *local, struct sockaddr_in *remote) { struct sockaddr_in bind_addr; int foreign_ok = 0; int ret; #ifdef CONFIG_HAP_LINUX_TPROXY static int ip_transp_working = 1; if (flags && ip_transp_working) { if (setsockopt(fd, SOL_IP, IP_TRANSPARENT, (char *) &one, sizeof(one)) == 0 || setsockopt(fd, SOL_IP, IP_FREEBIND, (char *) &one, sizeof(one)) == 0) foreign_ok = 1; else ip_transp_working = 0; } #endif if (flags) { memset(&bind_addr, 0, sizeof(bind_addr)); if (flags & 1) bind_addr.sin_addr = remote->sin_addr; if (flags & 2) bind_addr.sin_port = remote->sin_port; } setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one)); if (foreign_ok) { ret = bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr)); if (ret < 0) return 2; } else { ret = bind(fd, (struct sockaddr *)local, sizeof(*local)); if (ret < 0) return 1; } if (!flags) return 0; #ifdef CONFIG_HAP_CTTPROXY if (!foreign_ok) { struct in_tproxy itp1, itp2; memset(&itp1, 0, sizeof(itp1)); itp1.op = TPROXY_ASSIGN; itp1.v.addr.faddr = bind_addr.sin_addr; itp1.v.addr.fport = bind_addr.sin_port; /* set connect flag on socket */ itp2.op = TPROXY_FLAGS; itp2.v.flags = ITP_CONNECT | ITP_ONCE; if (setsockopt(fd, SOL_IP, IP_TPROXY, &itp1, sizeof(itp1)) != -1 && setsockopt(fd, SOL_IP, IP_TPROXY, &itp2, sizeof(itp2)) != -1) { foreign_ok = 1; } } #endif if (!foreign_ok) /* we could not bind to a foreign address */ return 2; return 0; } /* This function tries to bind a TCPv4/v6 listener. It may return a warning or * an error message in if the message is at most bytes long * (including '\0'). The return value is composed from ERR_ABORT, ERR_WARN, * ERR_ALERT, ERR_RETRYABLE and ERR_FATAL. ERR_NONE indicates that everything * was alright and that no message was returned. ERR_RETRYABLE means that an * error occurred but that it may vanish after a retry (eg: port in use), and * ERR_FATAL indicates a non-fixable error.ERR_WARN and ERR_ALERT do not alter * the meaning of the error, but just indicate that a message is present which * should be displayed with the respective level. Last, ERR_ABORT indicates * that it's pointless to try to start other listeners. No error message is * returned if errlen is NULL. */ int tcp_bind_listener(struct listener *listener, char *errmsg, int errlen) { __label__ tcp_return, tcp_close_return; int fd, err; const char *msg = NULL; /* ensure we never return garbage */ if (errmsg && errlen) *errmsg = 0; if (listener->state != LI_ASSIGNED) return ERR_NONE; /* already bound */ err = ERR_NONE; if ((fd = socket(listener->addr.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) { err |= ERR_RETRYABLE | ERR_ALERT; msg = "cannot create listening socket"; goto tcp_return; } if (fd >= global.maxsock) { err |= ERR_FATAL | ERR_ABORT | ERR_ALERT; msg = "not enough free sockets (raise '-n' parameter)"; goto tcp_close_return; } if ((fcntl(fd, F_SETFL, O_NONBLOCK) == -1) || (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (char *) &one, sizeof(one)) == -1)) { err |= ERR_FATAL | ERR_ALERT; msg = "cannot make socket non-blocking"; goto tcp_close_return; } if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one, sizeof(one)) == -1) { /* not fatal but should be reported */ msg = "cannot do so_reuseaddr"; err |= ERR_ALERT; } if (listener->options & LI_O_NOLINGER) setsockopt(fd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger)); #ifdef SO_REUSEPORT /* OpenBSD supports this. As it's present in old libc versions of Linux, * it might return an error that we will silently ignore. */ setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, (char *) &one, sizeof(one)); #endif #ifdef CONFIG_HAP_LINUX_TPROXY if ((listener->options & LI_O_FOREIGN) && (setsockopt(fd, SOL_IP, IP_TRANSPARENT, (char *) &one, sizeof(one)) == -1) && (setsockopt(fd, SOL_IP, IP_FREEBIND, (char *) &one, sizeof(one)) == -1)) { msg = "cannot make listening socket transparent"; err |= ERR_ALERT; } #endif #ifdef SO_BINDTODEVICE /* Note: this might fail if not CAP_NET_RAW */ if (listener->interface) { if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, listener->interface, strlen(listener->interface) + 1) == -1) { msg = "cannot bind listener to device"; err |= ERR_WARN; } } #endif if (bind(fd, (struct sockaddr *)&listener->addr, listener->proto->sock_addrlen) == -1) { err |= ERR_RETRYABLE | ERR_ALERT; msg = "cannot bind socket"; goto tcp_close_return; } if (listen(fd, listener->backlog ? listener->backlog : listener->maxconn) == -1) { err |= ERR_RETRYABLE | ERR_ALERT; msg = "cannot listen to socket"; goto tcp_close_return; } /* the socket is ready */ listener->fd = fd; listener->state = LI_LISTEN; /* the function for the accept() event */ fd_insert(fd); fdtab[fd].cb[DIR_RD].f = listener->accept; fdtab[fd].cb[DIR_WR].f = NULL; /* never called */ fdtab[fd].cb[DIR_RD].b = fdtab[fd].cb[DIR_WR].b = NULL; fdtab[fd].owner = listener; /* reference the listener instead of a task */ fdtab[fd].state = FD_STLISTEN; fdtab[fd].peeraddr = NULL; fdtab[fd].peerlen = 0; tcp_return: if (msg && errlen) strlcpy2(errmsg, msg, errlen); return err; tcp_close_return: close(fd); goto tcp_return; } /* This function creates all TCP sockets bound to the protocol entry . * It is intended to be used as the protocol's bind_all() function. * The sockets will be registered but not added to any fd_set, in order not to * loose them across the fork(). A call to enable_all_listeners() is needed * to complete initialization. The return value is composed from ERR_*. */ static int tcp_bind_listeners(struct protocol *proto) { struct listener *listener; int err = ERR_NONE; list_for_each_entry(listener, &proto->listeners, proto_list) { err |= tcp_bind_listener(listener, NULL, 0); if ((err & ERR_CODE) == ERR_ABORT) break; } return err; } /* Add listener to the list of tcpv4 listeners. The listener's state * is automatically updated from LI_INIT to LI_ASSIGNED. The number of * listeners is updated. This is the function to use to add a new listener. */ void tcpv4_add_listener(struct listener *listener) { if (listener->state != LI_INIT) return; listener->state = LI_ASSIGNED; listener->proto = &proto_tcpv4; LIST_ADDQ(&proto_tcpv4.listeners, &listener->proto_list); proto_tcpv4.nb_listeners++; } /* Add listener to the list of tcpv4 listeners. The listener's state * is automatically updated from LI_INIT to LI_ASSIGNED. The number of * listeners is updated. This is the function to use to add a new listener. */ void tcpv6_add_listener(struct listener *listener) { if (listener->state != LI_INIT) return; listener->state = LI_ASSIGNED; listener->proto = &proto_tcpv6; LIST_ADDQ(&proto_tcpv6.listeners, &listener->proto_list); proto_tcpv6.nb_listeners++; } /* This function performs the TCP request analysis on the current request. It * returns 1 if the processing can continue on next analysers, or zero if it * needs more data, encounters an error, or wants to immediately abort the * request. It relies on buffers flags, and updates s->req->analysers. Its * behaviour is rather simple: * - the analyser should check for errors and timeouts, and react as expected. * It does not have to close anything upon error, the caller will. Note that * the caller also knows how to report errors and timeouts. * - if the analyser does not have enough data, it must return 0 without calling * other ones. It should also probably do a buffer_write_dis() to ensure * that unprocessed data will not be forwarded. But that probably depends on * the protocol. * - if an analyser has enough data, it just has to pass on to the next * analyser without using buffer_write_dis() (enabled by default). * - if an analyser thinks it has no added value anymore staying here, it must * reset its bit from the analysers flags in order not to be called anymore. * * In the future, analysers should be able to indicate that they want to be * called after XXX bytes have been received (or transfered), and the min of * all's wishes will be used to ring back (unless a special condition occurs). */ int tcp_inspect_request(struct session *s, struct buffer *req) { struct tcp_rule *rule; int partial; DPRINTF(stderr,"[%u] %s: session=%p b=%p, exp(r,w)=%u,%u bf=%08x bl=%d analysers=%02x\n", now_ms, __FUNCTION__, s, req, req->rex, req->wex, req->flags, req->l, req->analysers); /* We don't know whether we have enough data, so must proceed * this way : * - iterate through all rules in their declaration order * - if one rule returns MISS, it means the inspect delay is * not over yet, then return immediately, otherwise consider * it as a non-match. * - if one rule returns OK, then return OK * - if one rule returns KO, then return KO */ if (req->flags & BF_SHUTR || !s->fe->tcp_req.inspect_delay || tick_is_expired(req->analyse_exp, now_ms)) partial = 0; else partial = ACL_PARTIAL; list_for_each_entry(rule, &s->fe->tcp_req.inspect_rules, list) { int ret = ACL_PAT_PASS; if (rule->cond) { ret = acl_exec_cond(rule->cond, s->fe, s, NULL, ACL_DIR_REQ | partial); if (ret == ACL_PAT_MISS) { buffer_write_dis(req); /* just set the request timeout once at the beginning of the request */ if (!tick_isset(req->analyse_exp) && s->fe->tcp_req.inspect_delay) req->analyse_exp = tick_add_ifset(now_ms, s->fe->tcp_req.inspect_delay); return 0; } ret = acl_pass(ret); if (rule->cond->pol == ACL_COND_UNLESS) ret = !ret; } if (ret) { /* we have a matching rule. */ if (rule->action == TCP_ACT_REJECT) { buffer_abort(req); buffer_abort(s->rep); req->analysers = 0; s->fe->failed_req++; if (!(s->flags & SN_ERR_MASK)) s->flags |= SN_ERR_PRXCOND; if (!(s->flags & SN_FINST_MASK)) s->flags |= SN_FINST_R; return 0; } /* otherwise accept */ break; } } /* if we get there, it means we have no rule which matches, or * we have an explicit accept, so we apply the default accept. */ req->analysers &= ~AN_REQ_INSPECT; req->analyse_exp = TICK_ETERNITY; return 1; } /* This function should be called to parse a line starting with the "tcp-request" * keyword. */ static int tcp_parse_tcp_req(char **args, int section_type, struct proxy *curpx, struct proxy *defpx, char *err, int errlen) { const char *ptr = NULL; unsigned int val; int retlen; if (!*args[1]) { snprintf(err, errlen, "missing argument for '%s' in %s '%s'", args[0], proxy_type_str(proxy), curpx->id); return -1; } if (!strcmp(args[1], "inspect-delay")) { if (curpx == defpx) { snprintf(err, errlen, "%s %s is not allowed in 'defaults' sections", args[0], args[1]); return -1; } if (!(curpx->cap & PR_CAP_FE)) { snprintf(err, errlen, "%s %s will be ignored because %s '%s' has no %s capability", args[0], args[1], proxy_type_str(proxy), curpx->id, "frontend"); return 1; } if (!*args[2] || (ptr = parse_time_err(args[2], &val, TIME_UNIT_MS))) { retlen = snprintf(err, errlen, "'%s %s' expects a positive delay in milliseconds, in %s '%s'", args[0], args[1], proxy_type_str(proxy), curpx->id); if (ptr && retlen < errlen) retlen += snprintf(err+retlen, errlen - retlen, " (unexpected character '%c')", *ptr); return -1; } if (curpx->tcp_req.inspect_delay) { snprintf(err, errlen, "ignoring %s %s (was already defined) in %s '%s'", args[0], args[1], proxy_type_str(proxy), curpx->id); return 1; } curpx->tcp_req.inspect_delay = val; return 0; } if (!strcmp(args[1], "content")) { int action; int warn = 0; int pol = ACL_COND_NONE; struct acl_cond *cond; struct tcp_rule *rule; if (curpx == defpx) { snprintf(err, errlen, "%s %s is not allowed in 'defaults' sections", args[0], args[1]); return -1; } if (!strcmp(args[2], "accept")) action = TCP_ACT_ACCEPT; else if (!strcmp(args[2], "reject")) action = TCP_ACT_REJECT; else { retlen = snprintf(err, errlen, "'%s %s' expects 'accept' or 'reject', in %s '%s' (was '%s')", args[0], args[1], proxy_type_str(curpx), curpx->id, args[2]); return -1; } pol = ACL_COND_NONE; cond = NULL; if (!strcmp(args[3], "if")) pol = ACL_COND_IF; else if (!strcmp(args[3], "unless")) pol = ACL_COND_UNLESS; /* Note: we consider "if TRUE" when there is no condition */ if (pol != ACL_COND_NONE && (cond = parse_acl_cond((const char **)args+4, &curpx->acl, pol)) == NULL) { retlen = snprintf(err, errlen, "error detected in %s '%s' while parsing '%s' condition", proxy_type_str(curpx), curpx->id, args[3]); return -1; } // FIXME: how to set this ? // cond->line = linenum; if (cond->requires & (ACL_USE_RTR_ANY | ACL_USE_L7_ANY)) { struct acl *acl; const char *name; acl = cond_find_require(cond, ACL_USE_RTR_ANY|ACL_USE_L7_ANY); name = acl ? acl->name : "(unknown)"; retlen = snprintf(err, errlen, "acl '%s' involves some %s criteria which will be ignored.", name, (acl->requires & ACL_USE_RTR_ANY) ? "response-only" : "layer 7"); warn++; } rule = (struct tcp_rule *)calloc(1, sizeof(*rule)); rule->cond = cond; rule->action = action; LIST_INIT(&rule->list); LIST_ADDQ(&curpx->tcp_req.inspect_rules, &rule->list); return warn; } snprintf(err, errlen, "unknown argument '%s' after '%s' in %s '%s'", args[1], args[0], proxy_type_str(proxy), curpx->id); return -1; } /* return the number of bytes in the request buffer */ static int acl_fetch_req_len(struct proxy *px, struct session *l4, void *l7, int dir, struct acl_expr *expr, struct acl_test *test) { if (!l4 || !l4->req) return 0; test->i = l4->req->l; test->flags = ACL_TEST_F_VOLATILE | ACL_TEST_F_MAY_CHANGE; return 1; } /* Return the version of the SSL protocol in the request. It supports both * SSLv3 (TLSv1) header format for any message, and SSLv2 header format for * the hello message. The SSLv3 format is described in RFC 2246 p49, and the * SSLv2 format is described here, and completed p67 of RFC 2246 : * http://wp.netscape.com/eng/security/SSL_2.html * * Note: this decoder only works with non-wrapping data. */ static int acl_fetch_req_ssl_ver(struct proxy *px, struct session *l4, void *l7, int dir, struct acl_expr *expr, struct acl_test *test) { int version, bleft, msg_len; const unsigned char *data; if (!l4 || !l4->req) return 0; msg_len = 0; bleft = l4->req->l; if (!bleft) goto too_short; data = (const unsigned char *)l4->req->w; if ((*data >= 0x14 && *data <= 0x17) || (*data == 0xFF)) { /* SSLv3 header format */ if (bleft < 5) goto too_short; version = (data[1] << 16) + data[2]; /* version: major, minor */ msg_len = (data[3] << 8) + data[4]; /* record length */ /* format introduced with SSLv3 */ if (version < 0x00030000) goto not_ssl; /* message length between 1 and 2^14 + 2048 */ if (msg_len < 1 || msg_len > ((1<<14) + 2048)) goto not_ssl; bleft -= 5; data += 5; } else { /* SSLv2 header format, only supported for hello (msg type 1) */ int rlen, plen, cilen, silen, chlen; if (*data & 0x80) { if (bleft < 3) goto too_short; /* short header format : 15 bits for length */ rlen = ((data[0] & 0x7F) << 8) | data[1]; plen = 0; bleft -= 2; data += 2; } else { if (bleft < 4) goto too_short; /* long header format : 14 bits for length + pad length */ rlen = ((data[0] & 0x3F) << 8) | data[1]; plen = data[2]; bleft -= 3; data += 2; } if (*data != 0x01) goto not_ssl; bleft--; data++; if (bleft < 8) goto too_short; version = (data[0] << 16) + data[1]; /* version: major, minor */ cilen = (data[2] << 8) + data[3]; /* cipher len, multiple of 3 */ silen = (data[4] << 8) + data[5]; /* session_id_len: 0 or 16 */ chlen = (data[6] << 8) + data[7]; /* 16<=challenge length<=32 */ bleft -= 8; data += 8; if (cilen % 3 != 0) goto not_ssl; if (silen && silen != 16) goto not_ssl; if (chlen < 16 || chlen > 32) goto not_ssl; if (rlen != 9 + cilen + silen + chlen) goto not_ssl; /* focus on the remaining data length */ msg_len = cilen + silen + chlen + plen; } /* We could recursively check that the buffer ends exactly on an SSL * fragment boundary and that a possible next segment is still SSL, * but that's a bit pointless. However, we could still check that * all the part of the request which fits in a buffer is already * there. */ if (msg_len > l4->req->max_len + l4->req->data - l4->req->w) msg_len = l4->req->max_len + l4->req->data - l4->req->w; if (bleft < msg_len) goto too_short; /* OK that's enough. We have at least the whole message, and we have * the protocol version. */ test->i = version; test->flags = ACL_TEST_F_VOLATILE; return 1; too_short: test->flags = ACL_TEST_F_MAY_CHANGE; not_ssl: return 0; } static struct cfg_kw_list cfg_kws = {{ },{ { CFG_LISTEN, "tcp-request", tcp_parse_tcp_req }, { 0, NULL, NULL }, }}; static struct acl_kw_list acl_kws = {{ },{ { "req_len", acl_parse_int, acl_fetch_req_len, acl_match_int, ACL_USE_L4REQ_VOLATILE }, { "req_ssl_ver", acl_parse_dotted_ver, acl_fetch_req_ssl_ver, acl_match_int, ACL_USE_L4REQ_VOLATILE }, { NULL, NULL, NULL, NULL }, }}; __attribute__((constructor)) static void __tcp_protocol_init(void) { protocol_register(&proto_tcpv4); protocol_register(&proto_tcpv6); cfg_register_keywords(&cfg_kws); acl_register_keywords(&acl_kws); } /* * Local variables: * c-indent-level: 8 * c-basic-offset: 8 * End: */