+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <common/defaults.h>
+#include <common/error.h>
+
+#include "unix.h"
+
+/*
+ * Connect to unix socket using the path name.
+ */
+int lttcomm_connect_unix_sock(const char *pathname)
+{
+ struct sockaddr_un sun;
+ int fd, ret, closeret;
+
+ fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (fd < 0) {
+ PERROR("socket");
+ ret = fd;
+ goto error;
+ }
+
+ memset(&sun, 0, sizeof(sun));
+ sun.sun_family = AF_UNIX;
+ strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
+ sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
+
+ ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
+ if (ret < 0) {
+ /*
+ * Don't print message on connect error, because connect is used in
+ * normal execution to detect if sessiond is alive.
+ */
+ goto error_connect;
+ }
+
+ return fd;
+
+error_connect:
+ closeret = close(fd);
+ if (closeret) {
+ PERROR("close");
+ }
+error:
+ return ret;
+}
+
+/*
+ * Do an accept(2) on the sock and return the new file descriptor. The socket
+ * MUST be bind(2) before.
+ */
+int lttcomm_accept_unix_sock(int sock)
+{
+ int new_fd;
+ struct sockaddr_un sun;
+ socklen_t len = 0;
+
+ /* Blocking call */
+ new_fd = accept(sock, (struct sockaddr *) &sun, &len);
+ if (new_fd < 0) {
+ PERROR("accept");
+ }
+
+ return new_fd;
+}
+
+/*
+ * Creates a AF_UNIX local socket using pathname bind the socket upon creation
+ * and return the fd.
+ */
+int lttcomm_create_unix_sock(const char *pathname)
+{
+ struct sockaddr_un sun;
+ int fd;
+ int ret = -1;
+
+ /* Create server socket */
+ if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
+ PERROR("socket");
+ goto error;
+ }
+
+ memset(&sun, 0, sizeof(sun));
+ sun.sun_family = AF_UNIX;
+ strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
+ sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
+
+ /* Unlink the old file if present */
+ (void) unlink(pathname);
+ ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
+ if (ret < 0) {
+ PERROR("bind");
+ goto error;
+ }
+
+ return fd;
+
+error:
+ return ret;
+}
+
+/*
+ * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
+ */
+int lttcomm_listen_unix_sock(int sock)
+{
+ int ret;
+
+ ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
+ if (ret < 0) {
+ PERROR("listen");
+ }
+
+ return ret;
+}
+
+/*
+ * Receive data of size len in put that data into the buf param. Using recvmsg
+ * API.
+ *
+ * Return the size of received data.
+ */
+ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret = -1;
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ do {
+ ret = recvmsg(sock, &msg, MSG_WAITALL);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0) {
+ PERROR("recvmsg");
+ }
+
+ return ret;
+}
+
+/*
+ * Send buf data of size len. Using sendmsg API.
+ *
+ * Return the size of sent data.
+ */
+ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret = -1;
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ ret = sendmsg(sock, &msg, 0);
+ if (ret < 0) {
+ /*
+ * Only warn about EPIPE when quiet mode is deactivated.
+ * We consider EPIPE as expected.
+ */
+ if (errno != EPIPE || !lttng_opt_quiet) {
+ PERROR("sendmsg");
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Shutdown cleanly a unix socket.
+ */
+int lttcomm_close_unix_sock(int sock)
+{
+ int ret, closeret;
+
+ /* Shutdown receptions and transmissions */
+ ret = shutdown(sock, SHUT_RDWR);
+ if (ret < 0) {
+ PERROR("shutdown");
+ }
+
+ closeret = close(sock);
+ if (closeret) {
+ PERROR("close");
+ }
+
+ return ret;
+}
+
+/*
+ * Send a message accompanied by fd(s) over a unix socket.
+ *
+ * Returns the size of data sent, or negative error value.
+ */
+ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
+{
+ struct msghdr msg;
+ struct cmsghdr *cmptr;
+ struct iovec iov[1];
+ ssize_t ret = -1;
+ unsigned int sizeof_fds = nb_fd * sizeof(int);
+ char tmp[CMSG_SPACE(sizeof_fds)];
+ char dummy = 0;
+
+ memset(&msg, 0, sizeof(msg));
+
+ if (nb_fd > LTTCOMM_MAX_SEND_FDS)
+ return -EINVAL;
+
+ msg.msg_control = (caddr_t)tmp;
+ msg.msg_controllen = CMSG_LEN(sizeof_fds);
+
+ cmptr = CMSG_FIRSTHDR(&msg);
+ cmptr->cmsg_level = SOL_SOCKET;
+ cmptr->cmsg_type = SCM_RIGHTS;
+ cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
+ memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
+ /* Sum of the length of all control messages in the buffer: */
+ msg.msg_controllen = cmptr->cmsg_len;
+
+ iov[0].iov_base = &dummy;
+ iov[0].iov_len = 1;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ do {
+ ret = sendmsg(sock, &msg, 0);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0) {
+ /*
+ * Only warn about EPIPE when quiet mode is deactivated.
+ * We consider EPIPE as expected.
+ */
+ if (errno != EPIPE || !lttng_opt_quiet) {
+ PERROR("sendmsg");
+ }
+ }
+ return ret;
+}
+
+/*
+ * Recv a message accompanied by fd(s) from a unix socket.
+ *
+ * Returns the size of received data, or negative error value.
+ *
+ * Expect at most "nb_fd" file descriptors. Returns the number of fd
+ * actually received in nb_fd.
+ */
+ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
+{
+ struct iovec iov[1];
+ ssize_t ret = 0;
+ struct cmsghdr *cmsg;
+ size_t sizeof_fds = nb_fd * sizeof(int);
+ char recv_fd[CMSG_SPACE(sizeof_fds)];
+ struct msghdr msg;
+ char dummy;
+
+ memset(&msg, 0, sizeof(msg));
+
+ /* Prepare to receive the structures */
+ iov[0].iov_base = &dummy;
+ iov[0].iov_len = 1;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = recv_fd;
+ msg.msg_controllen = sizeof(recv_fd);
+
+ do {
+ ret = recvmsg(sock, &msg, 0);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0) {
+ PERROR("recvmsg fds");
+ goto end;
+ }
+ if (ret != 1) {
+ fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
+ ret, 1);
+ goto end;
+ }
+ if (msg.msg_flags & MSG_CTRUNC) {
+ fprintf(stderr, "Error: Control message truncated.\n");
+ ret = -1;
+ goto end;
+ }
+ cmsg = CMSG_FIRSTHDR(&msg);
+ if (!cmsg) {
+ fprintf(stderr, "Error: Invalid control message header\n");
+ ret = -1;
+ goto end;
+ }
+ if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
+ fprintf(stderr, "Didn't received any fd\n");
+ ret = -1;
+ goto end;
+ }
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
+ fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
+ (size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
+ ret = -1;
+ goto end;
+ }
+ memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
+ ret = sizeof_fds;
+end:
+ return ret;
+}
+
+/*
+ * Send a message with credentials over a unix socket.
+ *
+ * Returns the size of data sent, or negative error value.
+ */
+ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret = -1;
+#ifdef __linux__
+ struct cmsghdr *cmptr;
+ size_t sizeof_cred = sizeof(lttng_sock_cred);
+ char anc_buf[CMSG_SPACE(sizeof_cred)];
+ lttng_sock_cred *creds;
+#endif /* __linux__ */
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+#ifdef __linux__
+ msg.msg_control = (caddr_t) anc_buf;
+ msg.msg_controllen = CMSG_LEN(sizeof_cred);
+
+ cmptr = CMSG_FIRSTHDR(&msg);
+ cmptr->cmsg_level = SOL_SOCKET;
+ cmptr->cmsg_type = LTTNG_SOCK_CREDS;
+ cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
+
+ creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
+
+ LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
+ LTTNG_SOCK_SET_GID_CRED(creds, getegid());
+ LTTNG_SOCK_SET_PID_CRED(creds, getpid());
+#endif /* __linux__ */
+
+ do {
+ ret = sendmsg(sock, &msg, 0);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0) {
+ /*
+ * Only warn about EPIPE when quiet mode is deactivated.
+ * We consider EPIPE as expected.
+ */
+ if (errno != EPIPE || !lttng_opt_quiet) {
+ PERROR("sendmsg");
+ }
+ }
+ return ret;
+}
+
+/*
+ * Recv a message accompanied with credentials from a unix socket.
+ *
+ * Returns the size of received data, or negative error value.
+ */
+ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
+ lttng_sock_cred *creds)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret;
+#ifdef __linux__
+ struct cmsghdr *cmptr;
+ size_t sizeof_cred = sizeof(lttng_sock_cred);
+ char anc_buf[CMSG_SPACE(sizeof_cred)];
+#endif /* __linux__ */
+
+ memset(&msg, 0, sizeof(msg));
+
+ /* Not allowed */
+ if (creds == NULL) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Prepare to receive the structures */
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+#ifdef __linux__
+ msg.msg_control = anc_buf;
+ msg.msg_controllen = sizeof(anc_buf);
+#endif /* __linux__ */
+
+ do {
+ ret = recvmsg(sock, &msg, 0);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0) {
+ PERROR("recvmsg fds");
+ goto end;
+ }
+
+#ifdef __linux__
+ if (msg.msg_flags & MSG_CTRUNC) {
+ fprintf(stderr, "Error: Control message truncated.\n");
+ ret = -1;
+ goto end;
+ }
+
+ cmptr = CMSG_FIRSTHDR(&msg);
+ if (cmptr == NULL) {
+ fprintf(stderr, "Error: Invalid control message header\n");
+ ret = -1;
+ goto end;
+ }
+
+ if (cmptr->cmsg_level != SOL_SOCKET ||
+ cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
+ fprintf(stderr, "Didn't received any credentials\n");
+ ret = -1;
+ goto end;
+ }
+
+ if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
+ fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
+ (size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
+ ret = -1;
+ goto end;
+ }
+
+ memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
+#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
+ {
+ int peer_ret;
+
+ peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
+ if (peer_ret != 0) {
+ return peer_ret;
+ }
+ }
+#else
+#error "Please implement credential support for your OS."
+#endif /* __linux__ */
+
+end:
+ return ret;
+}
+
+/*
+ * Set socket option to use credentials passing.
+ */
+#ifdef __linux__
+int lttcomm_setsockopt_creds_unix_sock(int sock)
+{
+ int ret, on = 1;
+
+ /* Set socket for credentials retrieval */
+ ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+ if (ret < 0) {
+ PERROR("setsockopt creds unix sock");
+ }
+ return ret;
+}
+#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
+int lttcomm_setsockopt_creds_unix_sock(int sock)
+{
+ return 0;
+}
+#else
+#error "Please implement credential support for your OS."
+#endif /* __linux__ */