diff options
Diffstat (limited to 'src/sock.c')
| -rw-r--r-- | src/sock.c | 1072 |
1 files changed, 1072 insertions, 0 deletions
diff --git a/src/sock.c b/src/sock.c new file mode 100644 index 0000000..7fcdc10 --- /dev/null +++ b/src/sock.c @@ -0,0 +1,1072 @@ +/* + * Generic code for native (BSD-compatible) sockets + * + * Copyright 2000-2020 Willy Tarreau <w@1wt.eu> + * + * 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. + * + */ + +#define _GNU_SOURCE +#include <ctype.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/types.h> + +#include <net/if.h> + +#include <haproxy/api.h> +#include <haproxy/activity.h> +#include <haproxy/connection.h> +#include <haproxy/listener.h> +#include <haproxy/log.h> +#include <haproxy/namespace.h> +#include <haproxy/proto_sockpair.h> +#include <haproxy/sock.h> +#include <haproxy/sock_inet.h> +#include <haproxy/tools.h> + +#define SOCK_XFER_OPT_FOREIGN 0x000000001 +#define SOCK_XFER_OPT_V6ONLY 0x000000002 +#define SOCK_XFER_OPT_DGRAM 0x000000004 + +/* the list of remaining sockets transferred from an older process */ +struct xfer_sock_list { + int fd; + int options; /* socket options as SOCK_XFER_OPT_* */ + char *iface; + char *namespace; + int if_namelen; + int ns_namelen; + struct xfer_sock_list *prev; + struct xfer_sock_list *next; + struct sockaddr_storage addr; +}; + +static struct xfer_sock_list *xfer_sock_list; + + +/* Accept an incoming connection from listener <l>, and return it, as well as + * a CO_AC_* status code into <status> if not null. Null is returned on error. + * <l> must be a valid listener with a valid frontend. + */ +struct connection *sock_accept_conn(struct listener *l, int *status) +{ +#ifdef USE_ACCEPT4 + static int accept4_broken; +#endif + struct proxy *p = l->bind_conf->frontend; + struct connection *conn = NULL; + struct sockaddr_storage *addr = NULL; + socklen_t laddr; + int ret; + int cfd; + + if (!sockaddr_alloc(&addr, NULL, 0)) + goto fail_addr; + + /* accept() will mark all accepted FDs O_NONBLOCK and the ones accepted + * in the master process as FD_CLOEXEC. It's not done for workers + * because 1) workers are not supposed to execute anything so there's + * no reason for uselessly slowing down everything, and 2) that would + * prevent us from implementing fd passing in the future. + */ +#ifdef USE_ACCEPT4 + laddr = sizeof(*conn->src); + + /* only call accept4() if it's known to be safe, otherwise fallback to + * the legacy accept() + fcntl(). + */ + if (unlikely(accept4_broken) || + (((cfd = accept4(l->rx.fd, (struct sockaddr*)addr, &laddr, + SOCK_NONBLOCK | (master ? SOCK_CLOEXEC : 0))) == -1) && + (errno == ENOSYS || errno == EINVAL || errno == EBADF) && + ((accept4_broken = 1)))) +#endif + { + laddr = sizeof(*conn->src); + if ((cfd = accept(l->rx.fd, (struct sockaddr*)addr, &laddr)) != -1) { + fd_set_nonblock(cfd); + if (master) + fd_set_cloexec(cfd); + } + } + + if (likely(cfd != -1)) { + if (unlikely(cfd >= global.maxsock)) { + send_log(p, LOG_EMERG, + "Proxy %s reached the configured maximum connection limit. Please check the global 'maxconn' value.\n", + p->id); + goto fail_conn; + } + + /* Perfect, the connection was accepted */ + conn = conn_new(&l->obj_type); + if (!conn) + goto fail_conn; + + conn->src = addr; + conn->handle.fd = cfd; + ret = CO_AC_DONE; + goto done; + } + + /* error conditions below */ + sockaddr_free(&addr); + + switch (errno) { +#if defined(EWOULDBLOCK) && defined(EAGAIN) && EWOULDBLOCK != EAGAIN + case EWOULDBLOCK: +#endif + case EAGAIN: + ret = CO_AC_DONE; /* nothing more to accept */ + if (fdtab[l->rx.fd].state & (FD_POLL_HUP|FD_POLL_ERR)) { + /* the listening socket might have been disabled in a shared + * process and we're a collateral victim. We'll just pause for + * a while in case it comes back. In the mean time, we need to + * clear this sticky flag. + */ + _HA_ATOMIC_AND(&fdtab[l->rx.fd].state, ~(FD_POLL_HUP|FD_POLL_ERR)); + ret = CO_AC_PAUSE; + } + fd_cant_recv(l->rx.fd); + break; + + case EINVAL: + /* might be trying to accept on a shut fd (eg: soft stop) */ + ret = CO_AC_PAUSE; + break; + + case EINTR: + case ECONNABORTED: + ret = CO_AC_RETRY; + break; + + case ENFILE: + if (p) + send_log(p, LOG_EMERG, + "Proxy %s reached system FD limit (maxsock=%d). Please check system tunables.\n", + p->id, global.maxsock); + ret = CO_AC_PAUSE; + break; + + case EMFILE: + if (p) + send_log(p, LOG_EMERG, + "Proxy %s reached process FD limit (maxsock=%d). Please check 'ulimit-n' and restart.\n", + p->id, global.maxsock); + ret = CO_AC_PAUSE; + break; + + case ENOBUFS: + case ENOMEM: + if (p) + send_log(p, LOG_EMERG, + "Proxy %s reached system memory limit (maxsock=%d). Please check system tunables.\n", + p->id, global.maxsock); + ret = CO_AC_PAUSE; + break; + + default: + /* unexpected result, let's give up and let other tasks run */ + ret = CO_AC_YIELD; + } + done: + if (status) + *status = ret; + return conn; + + fail_conn: + sockaddr_free(&addr); + /* The accept call already succeeded by the time we try to allocate the connection, + * we need to close it in case of failure. */ + close(cfd); + fail_addr: + ret = CO_AC_PAUSE; + goto done; +} + +/* Create a socket to connect to the server in conn->dst (which MUST be valid), + * using the configured namespace if needed, or the one passed by the proxy + * protocol if required to do so. It ultimately calls socket() or socketat() + * and returns the FD or error code. + */ +int sock_create_server_socket(struct connection *conn) +{ + const struct netns_entry *ns = NULL; + +#ifdef USE_NS + if (objt_server(conn->target)) { + if (__objt_server(conn->target)->flags & SRV_F_USE_NS_FROM_PP) + ns = conn->proxy_netns; + else + ns = __objt_server(conn->target)->netns; + } +#endif + return my_socketat(ns, conn->dst->ss_family, SOCK_STREAM, 0); +} + +/* Enables receiving on receiver <rx> once already bound. */ +void sock_enable(struct receiver *rx) +{ + if (rx->flags & RX_F_BOUND) + fd_want_recv_safe(rx->fd); +} + +/* Disables receiving on receiver <rx> once already bound. */ +void sock_disable(struct receiver *rx) +{ + if (rx->flags & RX_F_BOUND) + fd_stop_recv(rx->fd); +} + +/* stops, unbinds and possibly closes the FD associated with receiver rx */ +void sock_unbind(struct receiver *rx) +{ + /* There are a number of situations where we prefer to keep the FD and + * not to close it (unless we're stopping, of course): + * - worker process unbinding from a worker's non-suspendable FD (ABNS) => close + * - worker process unbinding from a worker's FD with socket transfer enabled => keep + * - master process unbinding from a master's inherited FD => keep + * - master process unbinding from a master's FD => close + * - master process unbinding from a worker's inherited FD => keep + * - master process unbinding from a worker's FD => close + * - worker process unbinding from a master's FD => close + * - worker process unbinding from a worker's FD => close + */ + if (rx->flags & RX_F_BOUND) + rx->proto->rx_disable(rx); + + if (!stopping && !master && + !(rx->flags & RX_F_MWORKER) && + !(rx->flags & RX_F_NON_SUSPENDABLE) && + (global.tune.options & GTUNE_SOCKET_TRANSFER)) + return; + + if (!stopping && master && + rx->flags & RX_F_INHERITED) + return; + + rx->flags &= ~RX_F_BOUND; + if (rx->fd != -1) + fd_delete(rx->fd); + rx->fd = -1; +} + +/* + * Retrieves the source address for the socket <fd>, with <dir> indicating + * if we're a listener (=0) or an initiator (!=0). It returns 0 in case of + * success, -1 in case of error. The socket's source address is stored in + * <sa> for <salen> bytes. + */ +int sock_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir) +{ + if (dir) + return getsockname(fd, sa, &salen); + else + return getpeername(fd, sa, &salen); +} + +/* + * Retrieves the original destination address for the socket <fd>, with <dir> + * indicating if we're a listener (=0) or an initiator (!=0). It returns 0 in + * case of success, -1 in case of error. The socket's source address is stored + * in <sa> for <salen> bytes. + */ +int sock_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir) +{ + if (dir) + return getpeername(fd, sa, &salen); + else + return getsockname(fd, sa, &salen); +} + +/* Try to retrieve exported sockets from worker at CLI <unixsocket>. These + * ones will be placed into the xfer_sock_list for later use by function + * sock_find_compatible_fd(). Returns 0 on success, -1 on failure. + */ +int sock_get_old_sockets(const char *unixsocket) +{ + char *cmsgbuf = NULL, *tmpbuf = NULL; + int *tmpfd = NULL; + struct sockaddr_un addr; + struct cmsghdr *cmsg; + struct msghdr msghdr; + struct iovec iov; + struct xfer_sock_list *xfer_sock = NULL; + struct timeval tv = { .tv_sec = 1, .tv_usec = 0 }; + int sock = -1; + int ret = -1; + int ret2 = -1; + int fd_nb; + int got_fd = 0; + int cur_fd = 0; + size_t maxoff = 0, curoff = 0; + + if (strncmp("sockpair@", unixsocket, strlen("sockpair@")) == 0) { + /* sockpair for master-worker usage */ + int sv[2]; + int dst_fd; + + dst_fd = strtoll(unixsocket + strlen("sockpair@"), NULL, 0); + + if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { + ha_warning("socketpair(): Cannot create socketpair. Giving up.\n"); + } + + if (send_fd_uxst(dst_fd, sv[0]) == -1) { + ha_alert("socketpair: Cannot transfer the fd %d over sockpair@%d. Giving up.\n", sv[0], dst_fd); + close(sv[0]); + close(sv[1]); + goto out; + } + + close(sv[0]); /* we don't need this side anymore */ + sock = sv[1]; + + } else { + /* Unix socket */ + + sock = socket(PF_UNIX, SOCK_STREAM, 0); + if (sock < 0) { + ha_warning("Failed to connect to the old process socket '%s'\n", unixsocket); + goto out; + } + + strncpy(addr.sun_path, unixsocket, sizeof(addr.sun_path) - 1); + addr.sun_path[sizeof(addr.sun_path) - 1] = 0; + addr.sun_family = PF_UNIX; + + ret = connect(sock, (struct sockaddr *)&addr, sizeof(addr)); + if (ret < 0) { + ha_warning("Failed to connect to the old process socket '%s'\n", unixsocket); + goto out; + } + + } + memset(&msghdr, 0, sizeof(msghdr)); + cmsgbuf = malloc(CMSG_SPACE(sizeof(int)) * MAX_SEND_FD); + if (!cmsgbuf) { + ha_warning("Failed to allocate memory to send sockets\n"); + goto out; + } + + setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (void *)&tv, sizeof(tv)); + iov.iov_base = &fd_nb; + iov.iov_len = sizeof(fd_nb); + msghdr.msg_iov = &iov; + msghdr.msg_iovlen = 1; + + if (send(sock, "_getsocks\n", strlen("_getsocks\n"), 0) != strlen("_getsocks\n")) { + ha_warning("Failed to get the number of sockets to be transferred !\n"); + goto out; + } + + /* First, get the number of file descriptors to be received */ + if (recvmsg(sock, &msghdr, MSG_WAITALL) != sizeof(fd_nb)) { + ha_warning("Failed to get the number of sockets to be transferred !\n"); + goto out; + } + + if (fd_nb == 0) { + ret2 = 0; + goto out; + } + + tmpbuf = malloc(fd_nb * (1 + MAXPATHLEN + 1 + IFNAMSIZ + sizeof(int))); + if (tmpbuf == NULL) { + ha_warning("Failed to allocate memory while receiving sockets\n"); + goto out; + } + + tmpfd = malloc(fd_nb * sizeof(int)); + if (tmpfd == NULL) { + ha_warning("Failed to allocate memory while receiving sockets\n"); + goto out; + } + + msghdr.msg_control = cmsgbuf; + msghdr.msg_controllen = CMSG_SPACE(sizeof(int)) * MAX_SEND_FD; + iov.iov_len = MAX_SEND_FD * (1 + MAXPATHLEN + 1 + IFNAMSIZ + sizeof(int)); + + do { + int ret3; + + iov.iov_base = tmpbuf + curoff; + + ret = recvmsg(sock, &msghdr, 0); + + if (ret == -1 && errno == EINTR) + continue; + + if (ret <= 0) + break; + + /* Send an ack to let the sender know we got the sockets + * and it can send some more + */ + do { + ret3 = send(sock, &got_fd, sizeof(got_fd), 0); + } while (ret3 == -1 && errno == EINTR); + + for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg != NULL; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) { + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { + size_t totlen = cmsg->cmsg_len - CMSG_LEN(0); + + if (totlen / sizeof(int) + got_fd > fd_nb) { + ha_warning("Got to many sockets !\n"); + goto out; + } + + /* + * Be paranoid and use memcpy() to avoid any + * potential alignment issue. + */ + memcpy(&tmpfd[got_fd], CMSG_DATA(cmsg), totlen); + got_fd += totlen / sizeof(int); + } + } + curoff += ret; + } while (got_fd < fd_nb); + + if (got_fd != fd_nb) { + ha_warning("We didn't get the expected number of sockets (expecting %d got %d)\n", + fd_nb, got_fd); + goto out; + } + + maxoff = curoff; + curoff = 0; + + for (cur_fd = 0; cur_fd < got_fd; cur_fd++) { + int fd = tmpfd[cur_fd]; + socklen_t socklen; + int val; + int len; + + xfer_sock = calloc(1, sizeof(*xfer_sock)); + if (!xfer_sock) { + ha_warning("Failed to allocate memory in get_old_sockets() !\n"); + break; + } + xfer_sock->fd = -1; + + socklen = sizeof(xfer_sock->addr); + if (getsockname(fd, (struct sockaddr *)&xfer_sock->addr, &socklen) != 0) { + ha_warning("Failed to get socket address\n"); + ha_free(&xfer_sock); + continue; + } + + if (curoff >= maxoff) { + ha_warning("Inconsistency while transferring sockets\n"); + goto out; + } + + len = tmpbuf[curoff++]; + if (len > 0) { + /* We have a namespace */ + if (curoff + len > maxoff) { + ha_warning("Inconsistency while transferring sockets\n"); + goto out; + } + xfer_sock->namespace = malloc(len + 1); + if (!xfer_sock->namespace) { + ha_warning("Failed to allocate memory while transferring sockets\n"); + goto out; + } + memcpy(xfer_sock->namespace, &tmpbuf[curoff], len); + xfer_sock->namespace[len] = 0; + xfer_sock->ns_namelen = len; + curoff += len; + } + + if (curoff >= maxoff) { + ha_warning("Inconsistency while transferring sockets\n"); + goto out; + } + + len = tmpbuf[curoff++]; + if (len > 0) { + /* We have an interface */ + if (curoff + len > maxoff) { + ha_warning("Inconsistency while transferring sockets\n"); + goto out; + } + xfer_sock->iface = malloc(len + 1); + if (!xfer_sock->iface) { + ha_warning("Failed to allocate memory while transferring sockets\n"); + goto out; + } + memcpy(xfer_sock->iface, &tmpbuf[curoff], len); + xfer_sock->iface[len] = 0; + xfer_sock->if_namelen = len; + curoff += len; + } + + if (curoff + sizeof(int) > maxoff) { + ha_warning("Inconsistency while transferring sockets\n"); + goto out; + } + + /* we used to have 32 bits of listener options here but we don't + * use them anymore. + */ + curoff += sizeof(int); + + /* determine the foreign status directly from the socket itself */ + if (sock_inet_is_foreign(fd, xfer_sock->addr.ss_family)) + xfer_sock->options |= SOCK_XFER_OPT_FOREIGN; + + socklen = sizeof(val); + if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &val, &socklen) == 0 && val == SOCK_DGRAM) + xfer_sock->options |= SOCK_XFER_OPT_DGRAM; + +#if defined(IPV6_V6ONLY) + /* keep only the v6only flag depending on what's currently + * active on the socket, and always drop the v4v6 one. + */ + socklen = sizeof(val); + if (xfer_sock->addr.ss_family == AF_INET6 && + getsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, &socklen) == 0 && val > 0) + xfer_sock->options |= SOCK_XFER_OPT_V6ONLY; +#endif + + xfer_sock->fd = fd; + if (xfer_sock_list) + xfer_sock_list->prev = xfer_sock; + xfer_sock->next = xfer_sock_list; + xfer_sock->prev = NULL; + xfer_sock_list = xfer_sock; + xfer_sock = NULL; + } + + ret2 = 0; +out: + /* If we failed midway make sure to close the remaining + * file descriptors + */ + if (tmpfd != NULL && cur_fd < got_fd) { + for (; cur_fd < got_fd; cur_fd++) { + close(tmpfd[cur_fd]); + } + } + + free(tmpbuf); + free(tmpfd); + free(cmsgbuf); + + if (sock != -1) + close(sock); + + if (xfer_sock) { + free(xfer_sock->namespace); + free(xfer_sock->iface); + if (xfer_sock->fd != -1) + close(xfer_sock->fd); + free(xfer_sock); + } + return (ret2); +} + +/* When binding the receivers, check if a socket has been sent to us by the + * previous process that we could reuse, instead of creating a new one. Note + * that some address family-specific options are checked on the listener and + * on the socket. Typically for AF_INET and AF_INET6, we check for transparent + * mode, and for AF_INET6 we also check for "v4v6" or "v6only". The reused + * socket is automatically removed from the list so that it's not proposed + * anymore. + */ +int sock_find_compatible_fd(const struct receiver *rx) +{ + struct xfer_sock_list *xfer_sock = xfer_sock_list; + int options = 0; + int if_namelen = 0; + int ns_namelen = 0; + int ret = -1; + + if (!rx->proto->fam->addrcmp) + return -1; + + if (rx->proto->proto_type == PROTO_TYPE_DGRAM) + options |= SOCK_XFER_OPT_DGRAM; + + if (rx->settings->options & RX_O_FOREIGN) + options |= SOCK_XFER_OPT_FOREIGN; + + if (rx->addr.ss_family == AF_INET6) { + /* Prepare to match the v6only option against what we really want. Note + * that sadly the two options are not exclusive to each other and that + * v6only is stronger than v4v6. + */ + if ((rx->settings->options & RX_O_V6ONLY) || + (sock_inet6_v6only_default && !(rx->settings->options & RX_O_V4V6))) + options |= SOCK_XFER_OPT_V6ONLY; + } + + if (rx->settings->interface) + if_namelen = strlen(rx->settings->interface); +#ifdef USE_NS + if (rx->settings->netns) + ns_namelen = rx->settings->netns->name_len; +#endif + + while (xfer_sock) { + if ((options == xfer_sock->options) && + (if_namelen == xfer_sock->if_namelen) && + (ns_namelen == xfer_sock->ns_namelen) && + (!if_namelen || strcmp(rx->settings->interface, xfer_sock->iface) == 0) && +#ifdef USE_NS + (!ns_namelen || strcmp(rx->settings->netns->node.key, xfer_sock->namespace) == 0) && +#endif + rx->proto->fam->addrcmp(&xfer_sock->addr, &rx->addr) == 0) + break; + xfer_sock = xfer_sock->next; + } + + if (xfer_sock != NULL) { + ret = xfer_sock->fd; + if (xfer_sock == xfer_sock_list) + xfer_sock_list = xfer_sock->next; + if (xfer_sock->prev) + xfer_sock->prev->next = xfer_sock->next; + if (xfer_sock->next) + xfer_sock->next->prev = xfer_sock->prev; + free(xfer_sock->iface); + free(xfer_sock->namespace); + free(xfer_sock); + } + return ret; +} + +/* After all protocols are bound, there may remain some old sockets that have + * been removed between the previous config and the new one. These ones must + * be dropped, otherwise they will remain open and may prevent a service from + * restarting. + */ +void sock_drop_unused_old_sockets() +{ + while (xfer_sock_list != NULL) { + struct xfer_sock_list *tmpxfer = xfer_sock_list->next; + + close(xfer_sock_list->fd); + free(xfer_sock_list->iface); + free(xfer_sock_list->namespace); + free(xfer_sock_list); + xfer_sock_list = tmpxfer; + } +} + +/* Tests if the receiver supports accepting connections. Returns positive on + * success, 0 if not possible, negative if the socket is non-recoverable. The + * rationale behind this is that inherited FDs may be broken and that shared + * FDs might have been paused by another process. + */ +int sock_accepting_conn(const struct receiver *rx) +{ + int opt_val = 0; + socklen_t opt_len = sizeof(opt_val); + + if (getsockopt(rx->fd, SOL_SOCKET, SO_ACCEPTCONN, &opt_val, &opt_len) == -1) + return -1; + + return opt_val; +} + +/* This is the FD handler IO callback for stream sockets configured for + * accepting incoming connections. It's a pass-through to listener_accept() + * which will iterate over the listener protocol's accept_conn() function. + * The FD's owner must be a listener. + */ +void sock_accept_iocb(int fd) +{ + struct listener *l = fdtab[fd].owner; + + if (!l) + return; + + BUG_ON(!!master != !!(l->rx.flags & RX_F_MWORKER)); + listener_accept(l); +} + +/* This completes the initialization of connection <conn> by inserting its FD + * into the fdtab, associating it with the regular connection handler. It will + * be bound to the current thread only. This call cannot fail. + */ +void sock_conn_ctrl_init(struct connection *conn) +{ + BUG_ON(conn->flags & CO_FL_FDLESS); + fd_insert(conn->handle.fd, conn, sock_conn_iocb, tgid, ti->ltid_bit); +} + +/* This completes the release of connection <conn> by removing its FD from the + * fdtab and deleting it. The connection must not use the FD anymore past this + * point. The FD may be modified in the connection. + */ +void sock_conn_ctrl_close(struct connection *conn) +{ + BUG_ON(conn->flags & CO_FL_FDLESS); + fd_delete(conn->handle.fd); + conn->handle.fd = DEAD_FD_MAGIC; +} + +/* This is the callback which is set when a connection establishment is pending + * and we have nothing to send. It may update the FD polling status to indicate + * !READY. It returns 0 if it fails in a fatal way or needs to poll to go + * further, otherwise it returns non-zero and removes the CO_FL_WAIT_L4_CONN + * flag from the connection's flags. In case of error, it sets CO_FL_ERROR and + * leaves the error code in errno. + */ +int sock_conn_check(struct connection *conn) +{ + struct sockaddr_storage *addr; + int fd = conn->handle.fd; + + if (conn->flags & CO_FL_ERROR) + return 0; + + if (!conn_ctrl_ready(conn)) + return 0; + + if (!(conn->flags & CO_FL_WAIT_L4_CONN)) + return 1; /* strange we were called while ready */ + + BUG_ON(conn->flags & CO_FL_FDLESS); + + if (!fd_send_ready(fd) && !(fdtab[fd].state & (FD_POLL_ERR|FD_POLL_HUP))) + return 0; + + /* Here we have 2 cases : + * - modern pollers, able to report ERR/HUP. If these ones return any + * of these flags then it's likely a failure, otherwise it possibly + * is a success (i.e. there may have been data received just before + * the error was reported). + * - select, which doesn't report these and with which it's always + * necessary either to try connect() again or to check for SO_ERROR. + * In order to simplify everything, we double-check using connect() as + * soon as we meet either of these delicate situations. Note that + * SO_ERROR would clear the error after reporting it! + */ + if (cur_poller.flags & HAP_POLL_F_ERRHUP) { + /* modern poller, able to report ERR/HUP */ + if ((fdtab[fd].state & (FD_POLL_IN|FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_IN) + goto done; + if ((fdtab[fd].state & (FD_POLL_OUT|FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_OUT) + goto done; + if (!(fdtab[fd].state & (FD_POLL_ERR|FD_POLL_HUP))) + goto wait; + /* error present, fall through common error check path */ + } + + /* Use connect() to check the state of the socket. This has the double + * advantage of *not* clearing the error (so that health checks can + * still use getsockopt(SO_ERROR)) and giving us the following info : + * - error + * - connecting (EALREADY, EINPROGRESS) + * - connected (EISCONN, 0) + */ + addr = conn->dst; + if ((conn->flags & CO_FL_SOCKS4) && obj_type(conn->target) == OBJ_TYPE_SERVER) + addr = &objt_server(conn->target)->socks4_addr; + + if (connect(fd, (const struct sockaddr *)addr, get_addr_len(addr)) == -1) { + if (errno == EALREADY || errno == EINPROGRESS) + goto wait; + + if (errno && errno != EISCONN) + goto out_error; + } + + done: + /* The FD is ready now, we'll mark the connection as complete and + * forward the event to the transport layer which will notify the + * data layer. + */ + conn->flags &= ~CO_FL_WAIT_L4_CONN; + fd_may_send(fd); + fd_cond_recv(fd); + errno = 0; // make health checks happy + return 1; + + out_error: + /* Write error on the file descriptor. Report it to the connection + * and disable polling on this FD. + */ + conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH; + HA_ATOMIC_AND(&fdtab[fd].state, ~FD_LINGER_RISK); + fd_stop_both(fd); + return 0; + + wait: + fd_cant_send(fd); + fd_want_send(fd); + return 0; +} + +/* I/O callback for fd-based connections. It calls the read/write handlers + * provided by the connection's sock_ops, which must be valid. + */ +void sock_conn_iocb(int fd) +{ + struct connection *conn = fdtab[fd].owner; + unsigned int flags; + int need_wake = 0; + struct tasklet *t; + + if (unlikely(!conn)) { + activity[tid].conn_dead++; + return; + } + + flags = conn->flags & ~CO_FL_ERROR; /* ensure to call the wake handler upon error */ + + if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && + ((fd_send_ready(fd) && fd_send_active(fd)) || + (fd_recv_ready(fd) && fd_recv_active(fd)))) { + /* Still waiting for a connection to establish and nothing was + * attempted yet to probe the connection. this will clear the + * CO_FL_WAIT_L4_CONN flag on success. + */ + if (!sock_conn_check(conn)) + goto leave; + need_wake = 1; + } + + if (fd_send_ready(fd) && fd_send_active(fd)) { + /* force reporting of activity by clearing the previous flags : + * we'll have at least ERROR or CONNECTED at the end of an I/O, + * both of which will be detected below. + */ + flags = 0; + if (conn->subs && conn->subs->events & SUB_RETRY_SEND) { + t = conn->subs->tasklet; + need_wake = 0; // wake will be called after this I/O + conn->subs->events &= ~SUB_RETRY_SEND; + if (!conn->subs->events) + conn->subs = NULL; + tasklet_wakeup(t); + } + fd_stop_send(fd); + } + + /* The data transfer starts here and stops on error and handshakes. Note + * that we must absolutely test conn->xprt at each step in case it suddenly + * changes due to a quick unexpected close(). + */ + if (fd_recv_ready(fd) && fd_recv_active(fd)) { + /* force reporting of activity by clearing the previous flags : + * we'll have at least ERROR or CONNECTED at the end of an I/O, + * both of which will be detected below. + */ + flags = 0; + if (conn->subs && conn->subs->events & SUB_RETRY_RECV) { + t = conn->subs->tasklet; + need_wake = 0; // wake will be called after this I/O + conn->subs->events &= ~SUB_RETRY_RECV; + if (!conn->subs->events) + conn->subs = NULL; + tasklet_wakeup(t); + } + fd_stop_recv(fd); + } + + leave: + /* we may have to finish to install a mux or to wake it up based on + * what was just done above. It may kill the connection so we have to + * be prpared not to use it anymore. + */ + if (conn_notify_mux(conn, flags, need_wake) < 0) + return; + + /* commit polling changes in case of error. + * WT: it seems that the last case where this could still be relevant + * is if a mux wake function above report a connection error but does + * not stop polling. Shouldn't we enforce this into the mux instead of + * having to deal with this ? + */ + if (unlikely(conn->flags & CO_FL_ERROR)) { + if (conn_ctrl_ready(conn)) + fd_stop_both(fd); + + if (conn->subs) { + t = conn->subs->tasklet; + conn->subs->events = 0; + if (!conn->subs->events) + conn->subs = NULL; + tasklet_wakeup(t); + } + } +} + +/* Drains possibly pending incoming data on the file descriptor attached to the + * connection. This is used to know whether we need to disable lingering on + * close. Returns non-zero if it is safe to close without disabling lingering, + * otherwise zero. + */ +int sock_drain(struct connection *conn) +{ + int turns = 2; + int fd = conn->handle.fd; + int len; + + BUG_ON(conn->flags & CO_FL_FDLESS); + + if (fdtab[fd].state & (FD_POLL_ERR|FD_POLL_HUP)) + goto shut; + + if (!(conn->flags & CO_FL_WANT_DRAIN) && !fd_recv_ready(fd)) + return 0; + + /* no drain function defined, use the generic one */ + + while (turns) { +#ifdef MSG_TRUNC_CLEARS_INPUT + len = recv(fd, NULL, INT_MAX, MSG_DONTWAIT | MSG_NOSIGNAL | MSG_TRUNC); + if (len == -1 && errno == EFAULT) +#endif + len = recv(fd, trash.area, trash.size, MSG_DONTWAIT | MSG_NOSIGNAL); + + if (len == 0) + goto shut; + + if (len < 0) { + if (errno == EAGAIN || errno == EWOULDBLOCK) { + /* connection not closed yet */ + fd_cant_recv(fd); + break; + } + if (errno == EINTR) /* oops, try again */ + continue; + /* other errors indicate a dead connection, fine. */ + goto shut; + } + /* OK we read some data, let's try again once */ + turns--; + } + + /* some data are still present, give up */ + return 0; + + shut: + /* we're certain the connection was shut down */ + HA_ATOMIC_AND(&fdtab[fd].state, ~FD_LINGER_RISK); + return 1; +} + +/* Checks the connection's FD for readiness of events <event_type>, which may + * only be a combination of SUB_RETRY_RECV and SUB_RETRY_SEND. Those which are + * ready are returned. The ones that are not ready are enabled. The caller is + * expected to do what is needed to handle ready events and to deal with + * subsequent wakeups caused by the requested events' readiness. + */ +int sock_check_events(struct connection *conn, int event_type) +{ + int ret = 0; + + BUG_ON(conn->flags & CO_FL_FDLESS); + + if (event_type & SUB_RETRY_RECV) { + if (fd_recv_ready(conn->handle.fd)) + ret |= SUB_RETRY_RECV; + else + fd_want_recv(conn->handle.fd); + } + + if (event_type & SUB_RETRY_SEND) { + if (fd_send_ready(conn->handle.fd)) + ret |= SUB_RETRY_SEND; + else + fd_want_send(conn->handle.fd); + } + + return ret; +} + +/* Ignore readiness events from connection's FD for events of types <event_type> + * which may only be a combination of SUB_RETRY_RECV and SUB_RETRY_SEND. + */ +void sock_ignore_events(struct connection *conn, int event_type) +{ + BUG_ON(conn->flags & CO_FL_FDLESS); + + if (event_type & SUB_RETRY_RECV) + fd_stop_recv(conn->handle.fd); + + if (event_type & SUB_RETRY_SEND) + fd_stop_send(conn->handle.fd); +} + +/* Live check to see if a socket type supports SO_REUSEPORT for the specified + * family and socket() settings. Returns non-zero on success, 0 on failure. Use + * protocol_supports_flag() instead, which checks cached flags. + */ +int _sock_supports_reuseport(const struct proto_fam *fam, int type, int protocol) +{ + int ret = 0; +#ifdef SO_REUSEPORT + struct sockaddr_storage ss; + socklen_t sl = sizeof(ss); + int fd1, fd2; + + /* for the check, we'll need two sockets */ + fd1 = fd2 = -1; + + /* ignore custom sockets */ + if (!fam || fam->sock_domain >= AF_MAX) + goto leave; + + fd1 = socket(fam->sock_domain, type, protocol); + if (fd1 < 0) + goto leave; + + if (setsockopt(fd1, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) < 0) + goto leave; + + /* bind to any address assigned by the kernel, we'll then try to do it twice */ + memset(&ss, 0, sizeof(ss)); + ss.ss_family = fam->sock_family; + if (bind(fd1, (struct sockaddr *)&ss, fam->sock_addrlen) < 0) + goto leave; + + if (getsockname(fd1, (struct sockaddr *)&ss, &sl) < 0) + goto leave; + + fd2 = socket(fam->sock_domain, type, protocol); + if (fd2 < 0) + goto leave; + + if (setsockopt(fd2, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) < 0) + goto leave; + + if (bind(fd2, (struct sockaddr *)&ss, sl) < 0) + goto leave; + + /* OK we could bind twice to the same address:port, REUSEPORT + * is supported for this protocol. + */ + ret = 1; + + leave: + if (fd2 >= 0) + close(fd2); + if (fd1 >= 0) + close(fd1); +#endif + return ret; +} + +/* + * Local variables: + * c-indent-level: 8 + * c-basic-offset: 8 + * End: + */ |