--- /dev/null
+/*
+ * Socket Pair protocol layer (sockpair)
+ *
+ * Copyright HAProxy Technologies - William Lallemand <wlallemand@haproxy.com>
+ *
+ * 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 <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <time.h>
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+
+#include <common/compat.h>
+#include <common/config.h>
+#include <common/debug.h>
+#include <common/errors.h>
+#include <common/mini-clist.h>
+#include <common/standard.h>
+#include <common/time.h>
+#include <common/version.h>
+
+#include <types/global.h>
+
+#include <proto/connection.h>
+#include <proto/fd.h>
+#include <proto/freq_ctr.h>
+#include <proto/listener.h>
+#include <proto/log.h>
+#include <proto/protocol.h>
+#include <proto/task.h>
+
+static void sockpair_add_listener(struct listener *listener, int port);
+static int sockpair_bind_listener(struct listener *listener, char *errmsg, int errlen);
+static int sockpair_bind_listeners(struct protocol *proto, char *errmsg, int errlen);
+static int sockpair_connect_server(struct connection *conn, int data, int delack);
+
+/* Note: must not be declared <const> as its list will be overwritten */
+static struct protocol proto_sockpair = {
+ .name = "sockpair",
+ .sock_domain = AF_CUST_SOCKPAIR,
+ .sock_type = SOCK_STREAM,
+ .sock_prot = 0,
+ .sock_family = AF_UNIX,
+ .sock_addrlen = sizeof(struct sockaddr_un),
+ .l3_addrlen = sizeof(((struct sockaddr_un*)0)->sun_path),/* path len */
+ .accept = &listener_accept,
+ .connect = &sockpair_connect_server,
+ .bind = sockpair_bind_listener,
+ .bind_all = sockpair_bind_listeners,
+ .unbind_all = NULL,
+ .enable_all = enable_all_listeners,
+ .disable_all = disable_all_listeners,
+ .get_src = NULL,
+ .get_dst = NULL,
+ .pause = NULL,
+ .add = sockpair_add_listener,
+ .listeners = LIST_HEAD_INIT(proto_sockpair.listeners),
+ .nb_listeners = 0,
+};
+
+/* Add <listener> to the list of sockpair listeners (port is ignored). The
+ * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
+ * The number of listeners for the protocol is updated.
+ */
+static void sockpair_add_listener(struct listener *listener, int port)
+{
+ if (listener->state != LI_INIT)
+ return;
+ listener->state = LI_ASSIGNED;
+ listener->proto = &proto_sockpair;
+ LIST_ADDQ(&proto_sockpair.listeners, &listener->proto_list);
+ proto_sockpair.nb_listeners++;
+}
+
+/* This function creates all UNIX sockets bound to the protocol entry <proto>.
+ * 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 uxst_enable_listeners() is needed
+ * to complete initialization.
+ *
+ * The return value is composed from ERR_NONE, ERR_RETRYABLE and ERR_FATAL.
+ */
+static int sockpair_bind_listeners(struct protocol *proto, char *errmsg, int errlen)
+{
+ struct listener *listener;
+ int err = ERR_NONE;
+
+ list_for_each_entry(listener, &proto->listeners, proto_list) {
+ err |= sockpair_bind_listener(listener, errmsg, errlen);
+ if (err & ERR_ABORT)
+ break;
+ }
+ return err;
+}
+
+/* This function changes the state from ASSIGNED to LISTEN. The socket is NOT
+ * enabled for polling. The return value is composed from ERR_NONE,
+ * ERR_RETRYABLE and ERR_FATAL. It may return a warning or an error message in
+ * <errmsg> if the message is at most <errlen> bytes long (including '\0').
+ * Note that <errmsg> may be NULL if <errlen> is also zero.
+ */
+static int sockpair_bind_listener(struct listener *listener, char *errmsg, int errlen)
+{
+ int fd = listener->fd;
+ int err;
+ const char *msg = NULL;
+
+ err = ERR_NONE;
+
+ /* ensure we never return garbage */
+ if (errlen)
+ *errmsg = 0;
+
+ if (listener->state != LI_ASSIGNED)
+ return ERR_NONE; /* already bound */
+
+ if (listener->fd == -1) {
+ err |= ERR_FATAL | ERR_ALERT;
+ msg = "sockpair can be only used with inherited FDs";
+ goto err_return;
+ }
+
+ if (fd >= global.maxsock) {
+ err |= ERR_FATAL | ERR_ALERT;
+ msg = "socket(): not enough free sockets, raise -n argument";
+ goto err_return;
+ }
+ if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
+ err |= ERR_FATAL | ERR_ALERT;
+ msg = "cannot make sockpair non-blocking";
+ goto err_return;
+ }
+
+ listener->state = LI_LISTEN;
+
+ fd_insert(fd, listener, listener->proto->accept,
+ listener->bind_conf->bind_thread[relative_pid-1] ?
+ listener->bind_conf->bind_thread[relative_pid-1] : MAX_THREADS_MASK);
+
+ return err;
+
+ err_return:
+ if (msg && errlen)
+ snprintf(errmsg, errlen, "%s [fd %d]", msg, fd);
+ return err;
+}
+
+/*
+ * Send FD over a unix socket
+ *
+ * <send_fd> is the FD to send
+ * <fd> is the fd of the unix socket to use for the transfer
+ *
+ * The iobuf variable could be use in the future to enhance the protocol.
+ */
+int send_fd_uxst(int fd, int send_fd)
+{
+ char iobuf[2];
+ struct iovec iov;
+ struct msghdr msghdr;
+
+ char cmsgbuf[CMSG_SPACE(sizeof(int))];
+ char buf[CMSG_SPACE(sizeof(int))];
+ struct cmsghdr *cmsg = (void *)buf;
+
+ int *fdptr;
+
+ iov.iov_base = iobuf;
+ iov.iov_len = sizeof(iobuf);
+
+ memset(&msghdr, 0, sizeof(msghdr));
+ msghdr.msg_iov = &iov;
+ msghdr.msg_iovlen = 1;
+
+ /* Now send the fds */
+ msghdr.msg_control = cmsgbuf;
+ msghdr.msg_controllen = CMSG_SPACE(sizeof(int));
+
+ cmsg = CMSG_FIRSTHDR(&msghdr);
+ cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+
+ fdptr = (int *)CMSG_DATA(cmsg);
+ memcpy(fdptr, &send_fd, sizeof(send_fd));
+
+ if (sendmsg(fd, &msghdr, 0) != sizeof(iobuf)) {
+ ha_warning("Failed to transfer socket\n");
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ *
+ * This function works like uxst_connect_server but insteads of creating a
+ * socket and establishing a connection, it creates a pair of connected
+ * sockets, and send one of them through the destination FD. The destination FD
+ * is stored in addr.to->sin_addr.s_addr during configuration parsing.
+ *
+ * conn->target may point either to a valid server or to a backend, depending
+ * on conn->target. Only OBJ_TYPE_PROXY and OBJ_TYPE_SERVER are supported. The
+ * <data> parameter is a boolean indicating whether there are data waiting for
+ * being sent or not, in order to adjust data write polling and on some
+ * platforms. The <delack> argument is ignored.
+ *
+ * Note that a pending send_proxy message accounts for data.
+ *
+ * It can return one of :
+ * - SF_ERR_NONE if everything's OK
+ * - SF_ERR_SRVTO if there are no more servers
+ * - SF_ERR_SRVCL if the connection was refused by the server
+ * - SF_ERR_PRXCOND if the connection has been limited by the proxy (maxconn)
+ * - SF_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...)
+ * - SF_ERR_INTERNAL for any other purely internal errors
+ * Additionally, in the case of SF_ERR_RESOURCE, an emergency log will be emitted.
+ *
+ * The connection's fd is inserted only when SF_ERR_NONE is returned, otherwise
+ * it's invalid and the caller has nothing to do.
+ */
+static int sockpair_connect_server(struct connection *conn, int data, int delack)
+{
+ int sv[2], fd, dst_fd = -1;
+
+ /* the FD is stored in the sockaddr struct */
+ dst_fd = ((struct sockaddr_in *)&conn->addr.to)->sin_addr.s_addr;
+
+ conn->flags = 0;
+
+ if (obj_type(conn->target) != OBJ_TYPE_PROXY &&
+ obj_type(conn->target) != OBJ_TYPE_SERVER) {
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_INTERNAL;
+ }
+
+ if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
+ ha_alert("socketpair(): Cannot create socketpair. Giving up.\n");
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_RESOURCE;
+ }
+
+ fd = conn->handle.fd = sv[1];
+
+ if (fd >= global.maxsock) {
+ /* do not log anything there, it's a normal condition when this option
+ * is used to serialize connections to a server !
+ */
+ ha_alert("socket(): not enough free sockets. Raise -n argument. Giving up.\n");
+ close(sv[0]);
+ close(sv[1]);
+ conn->err_code = CO_ER_CONF_FDLIM;
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_PRXCOND; /* it is a configuration limit */
+ }
+
+ if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
+ qfprintf(stderr,"Cannot set client socket to non blocking mode.\n");
+ close(sv[0]);
+ close(sv[1]);
+ conn->err_code = CO_ER_SOCK_ERR;
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_INTERNAL;
+ }
+
+ /* if a send_proxy is there, there are data */
+ data |= conn->send_proxy_ofs;
+
+ if (global.tune.server_sndbuf)
+ setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &global.tune.server_sndbuf, sizeof(global.tune.server_sndbuf));
+
+ if (global.tune.server_rcvbuf)
+ setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &global.tune.server_rcvbuf, sizeof(global.tune.server_rcvbuf));
+
+ /* The new socket is sent on the other side, it should be retrieved and
+ * considered as an 'accept' socket on the server side */
+ if (send_fd_uxst(dst_fd, sv[0]) == -1) {
+ close(sv[0]);
+ close(sv[1]);
+ conn->err_code = CO_ER_SOCK_ERR;
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_INTERNAL;
+ }
+
+ close(sv[0]); /* we don't need this side anymore */
+
+ conn->flags &= ~CO_FL_WAIT_L4_CONN;
+
+ conn->flags |= CO_FL_ADDR_TO_SET;
+
+ /* Prepare to send a few handshakes related to the on-wire protocol. */
+ if (conn->send_proxy_ofs)
+ conn->flags |= CO_FL_SEND_PROXY;
+
+ conn_ctrl_init(conn); /* registers the FD */
+ fdtab[fd].linger_risk = 0; /* no need to disable lingering */
+
+ if (conn_xprt_init(conn) < 0) {
+ conn_full_close(conn);
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_RESOURCE;
+ }
+
+ if (conn->flags & (CO_FL_HANDSHAKE | CO_FL_WAIT_L4_CONN)) {
+ conn_sock_want_send(conn); /* for connect status, proxy protocol or SSL */
+ }
+ else {
+ /* If there's no more handshake, we need to notify the data
+ * layer when the connection is already OK otherwise we'll have
+ * no other opportunity to do it later (eg: health checks).
+ */
+ data = 1;
+ }
+
+ if (data)
+ conn_xprt_want_send(conn); /* prepare to send data if any */
+
+ return SF_ERR_NONE; /* connection is OK */
+}
+
+
+/*
+ * Receive a file descriptor transfered from a unix socket.
+ *
+ * Return -1 or a socket fd;
+ *
+ * The iobuf variable could be use in the future to enhance the protocol.
+ */
+int recv_fd_uxst(int sock)
+{
+ struct msghdr msghdr;
+ struct iovec iov;
+ char iobuf[2];
+
+ char cmsgbuf[CMSG_SPACE(sizeof(int))];
+ char buf[CMSG_SPACE(sizeof(int))];
+ struct cmsghdr *cmsg = (void *)buf;
+
+
+ int recv_fd = -1;
+ int ret = -1;
+
+ memset(&msghdr, 0, sizeof(msghdr));
+
+ iov.iov_base = iobuf;
+ iov.iov_len = sizeof(iobuf);
+
+ msghdr.msg_iov = &iov;
+ msghdr.msg_iovlen = 1;
+
+ msghdr.msg_control = cmsgbuf;
+ msghdr.msg_controllen = CMSG_SPACE(sizeof(int));
+
+ iov.iov_len = sizeof(iobuf);
+ iov.iov_base = iobuf;
+
+ while (1) {
+ ret = recvmsg(sock, &msghdr, 0);
+ if (ret == -1 && errno == EINTR)
+ continue;
+ else
+ break;
+ }
+
+ if (ret == -1)
+ return ret;
+
+ cmsg = CMSG_FIRSTHDR(&msghdr);
+ if (cmsg->cmsg_level == SOL_SOCKET &&
+ cmsg->cmsg_type == SCM_RIGHTS) {
+ size_t totlen = cmsg->cmsg_len -
+ CMSG_LEN(0);
+ memcpy(&recv_fd, CMSG_DATA(cmsg), totlen);
+ }
+ return recv_fd;
+}
+
+__attribute__((constructor))
+static void __uxst_protocol_init(void)
+{
+ protocol_register(&proto_sockpair);
+}
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ */
projects / thirdparty / haproxy.git / commitdiff
