--- /dev/null
+/*
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <common/common.h>
+#include <common/compat/errno.h>
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/fd-handle.h>
+
+#include "unix.h"
+
+/*
+ * Connect to unix socket using the path name.
+ */
+int lttcomm_connect_unix_sock(const char *pathname)
+{
+ struct sockaddr_un s_un;
+ int fd, ret, closeret;
+
+ if (strlen(pathname) >= sizeof(s_un.sun_path)) {
+ ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
+ pathname, strlen(pathname) + 1,
+ sizeof(s_un.sun_path));
+ ret = -ENAMETOOLONG;
+ goto error;
+ }
+
+ fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (fd < 0) {
+ PERROR("socket");
+ ret = fd;
+ goto error;
+ }
+
+ memset(&s_un, 0, sizeof(s_un));
+ s_un.sun_family = AF_UNIX;
+ strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
+ s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
+
+ ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un));
+ 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 s_un;
+ socklen_t len = sizeof(s_un);
+
+ /* Blocking call */
+ new_fd = accept(sock, (struct sockaddr *) &s_un, &len);
+ if (new_fd < 0) {
+ PERROR("accept");
+ }
+
+ return new_fd;
+}
+
+int lttcomm_create_anon_unix_socketpair(int *fds)
+{
+ if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
+ PERROR("socketpair");
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * 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 s_un;
+ int fd = -1;
+ int ret = -1;
+
+ if (strlen(pathname) >= sizeof(s_un.sun_path)) {
+ ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
+ pathname, strlen(pathname) + 1,
+ sizeof(s_un.sun_path));
+ ret = -ENAMETOOLONG;
+ goto error;
+ }
+
+ /* Create server socket */
+ if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
+ PERROR("socket");
+ goto error;
+ }
+
+ memset(&s_un, 0, sizeof(s_un));
+ s_un.sun_family = AF_UNIX;
+ strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
+ s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
+
+ /* Unlink the old file if present */
+ (void) unlink(pathname);
+ ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un));
+ if (ret < 0) {
+ PERROR("bind");
+ goto error;
+ }
+
+ return fd;
+
+error:
+ if (fd >= 0) {
+ if (close(fd) < 0) {
+ PERROR("close create unix sock");
+ }
+ }
+ 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;
+ size_t len_last;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(buf);
+ LTTNG_ASSERT(len > 0);
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ do {
+ len_last = iov[0].iov_len;
+ ret = lttng_recvmsg_nosigpipe(sock, &msg);
+ if (ret > 0) {
+ iov[0].iov_base = (char *) iov[0].iov_base + ret;
+ iov[0].iov_len -= ret;
+ LTTNG_ASSERT(ret <= len_last);
+ }
+ } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
+ if (ret < 0) {
+ PERROR("recvmsg");
+ } else if (ret > 0) {
+ ret = len;
+ }
+ /* Else ret = 0 meaning an orderly shutdown. */
+
+ return ret;
+}
+
+/*
+ * Receive data of size len in put that data into the buf param. Using recvmsg
+ * API. Only use with sockets set in non-blocking mode.
+ *
+ * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
+ * poll set. The poll loop will handle the EPIPE original cause.
+ *
+ * Return the size of received data.
+ */
+ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(buf);
+ LTTNG_ASSERT(len > 0);
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+retry:
+ ret = lttng_recvmsg_nosigpipe(sock, &msg);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ goto retry;
+ } else {
+ /*
+ * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
+ */
+ if (errno == EAGAIN || errno == EWOULDBLOCK ||
+ errno == EPIPE) {
+ /*
+ * Nothing was recv.
+ */
+ ret = 0;
+ goto end;
+ }
+
+ /* Unexpected error */
+ PERROR("recvmsg");
+ ret = -1;
+ goto end;
+ }
+ }
+
+end:
+ 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, const void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(buf);
+ LTTNG_ASSERT(len > 0);
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = (void *) buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ while (iov[0].iov_len) {
+ ret = sendmsg(sock, &msg, 0);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ continue;
+ } else {
+ /*
+ * Only warn about EPIPE when quiet mode is
+ * deactivated.
+ * We consider EPIPE as expected.
+ */
+ if (errno != EPIPE || !lttng_opt_quiet) {
+ PERROR("sendmsg");
+ }
+ goto end;
+ }
+ }
+ iov[0].iov_len -= ret;
+ iov[0].iov_base = (char *) iov[0].iov_base + ret;
+ }
+ ret = len;
+end:
+ return ret;
+}
+
+/*
+ * Send buf data of size len. Using sendmsg API.
+ * Only use with non-blocking sockets. The difference with the blocking version
+ * of the function is that this one does not retry to send on partial sends,
+ * except if the interruption was caused by a signal (EINTR).
+ *
+ * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
+ * poll set. The poll loop will handle the EPIPE original cause.
+ *
+ * Return the size of sent data.
+ */
+ssize_t lttcomm_send_unix_sock_non_block(int sock, const void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(buf);
+ LTTNG_ASSERT(len > 0);
+
+ memset(&msg, 0, sizeof(msg));
+
+ iov[0].iov_base = (void *) buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+retry:
+ ret = sendmsg(sock, &msg, 0);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ goto retry;
+ } else {
+ /*
+ * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
+ */
+ if (errno == EAGAIN || errno == EWOULDBLOCK ||
+ errno == EPIPE) {
+ /*
+ * This can happen in non blocking mode.
+ * Nothing was sent.
+ */
+ ret = 0;
+ goto end;
+ }
+
+ /* Unexpected error */
+ PERROR("sendmsg");
+ ret = -1;
+ goto end;
+ }
+ }
+end:
+ 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, const 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;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(fds);
+ LTTNG_ASSERT(nb_fd > 0);
+
+ memset(&msg, 0, sizeof(msg));
+ memset(tmp, 0, sizeof(tmp));
+
+ 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);
+ if (!cmptr) {
+ return -1;
+ }
+
+ 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;
+}
+
+/*
+ * Send the fd(s) of a payload view over a unix socket.
+ *
+ * Returns the size of data sent, or negative error value.
+ */
+static
+ssize_t _lttcomm_send_payload_view_fds_unix_sock(int sock,
+ struct lttng_payload_view *view,
+ bool blocking)
+{
+ int i;
+ ssize_t ret;
+ struct lttng_dynamic_array raw_fds;
+ const int fd_count = lttng_payload_view_get_fd_handle_count(view);
+
+ lttng_dynamic_array_init(&raw_fds, sizeof(int), NULL);
+
+ if (fd_count < 0) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ /*
+ * Prepare a contiguous array of file descriptors to send them.
+ *
+ * Note that the reference to each fd is released during the iteration;
+ * we're just getting the numerical value of the fds to conform to the
+ * syscall's interface. We rely on the fact that "view" must remain
+ * valid for the duration of the call and that the underlying payload
+ * owns a reference to the fd_handles.
+ */
+ for (i = 0; i < fd_count; i++) {
+ struct fd_handle *handle =
+ lttng_payload_view_pop_fd_handle(view);
+ const int raw_fd = fd_handle_get_fd(handle);
+ const int add_ret = lttng_dynamic_array_add_element(
+ &raw_fds, &raw_fd);
+
+ fd_handle_put(handle);
+ if (add_ret) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ if (blocking) {
+ ret = lttcomm_send_fds_unix_sock(sock,
+ (const int *) raw_fds.buffer.data, fd_count);
+ } else {
+ ret = lttcomm_send_fds_unix_sock_non_block(sock,
+ (const int *) raw_fds.buffer.data, fd_count);
+ }
+
+end:
+ lttng_dynamic_array_reset(&raw_fds);
+ return ret;
+}
+
+ssize_t lttcomm_send_payload_view_fds_unix_sock(int sock,
+ struct lttng_payload_view *view)
+{
+ return _lttcomm_send_payload_view_fds_unix_sock(sock, view, true);
+}
+
+ssize_t lttcomm_send_payload_view_fds_unix_sock_non_block(int sock,
+ struct lttng_payload_view *view)
+{
+ return _lttcomm_send_payload_view_fds_unix_sock(sock, view, false);
+}
+
+/*
+ * Send a message accompanied by fd(s) over a unix socket.
+ * Only use for non blocking socket.
+ *
+ * Returns the size of data sent, or negative error value.
+ */
+ssize_t lttcomm_send_fds_unix_sock_non_block(int sock, const 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;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(fds);
+ LTTNG_ASSERT(nb_fd > 0);
+
+ memset(&msg, 0, sizeof(msg));
+ memset(tmp, 0, sizeof(tmp));
+
+ 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);
+ if (!cmptr) {
+ return -1;
+ }
+
+ 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;
+
+retry:
+ ret = sendmsg(sock, &msg, 0);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ goto retry;
+ } else {
+ /*
+ * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
+ */
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ /*
+ * This can happen in non blocking mode.
+ * Nothing was sent.
+ */
+ ret = 0;
+ goto end;
+ }
+
+ if (errno == EPIPE) {
+ /* Expected error, pass error to caller */
+ DBG3("EPIPE on sendmsg");
+ ret = -1;
+ goto end;
+ }
+
+ /* Unexpected error */
+ PERROR("sendmsg");
+ ret = -1;
+ goto end;
+ }
+ }
+
+end:
+ 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);
+
+#ifdef __linux__
+/* Account for the struct ucred cmsg in the buffer size */
+#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
+#else
+#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
+#endif /* __linux__ */
+
+ char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE];
+ struct msghdr msg;
+ char dummy;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(fds);
+ LTTNG_ASSERT(nb_fd > 0);
+
+ 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;
+
+ cmsg = (struct cmsghdr *) recv_buf;
+ cmsg->cmsg_len = CMSG_LEN(sizeof_fds);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+
+ msg.msg_control = cmsg;
+ msg.msg_controllen = CMSG_LEN(sizeof(recv_buf));
+ msg.msg_flags = 0;
+
+retry:
+ ret = lttng_recvmsg_nosigpipe(sock, &msg);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ goto retry;
+ } else {
+ /* We consider EPIPE and EAGAIN as expected. */
+ if (!lttng_opt_quiet &&
+ (errno != EPIPE && errno != EAGAIN)) {
+ PERROR("recvmsg");
+ }
+ 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;
+ }
+
+ /*
+ * If the socket was configured with SO_PASSCRED, the kernel will add a
+ * control message (cmsg) to the ancillary data of the unix socket. We
+ * need to expect a cmsg of the SCM_CREDENTIALS as the first control
+ * message.
+ */
+ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+ if (cmsg->cmsg_level != SOL_SOCKET) {
+ fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n");
+ ret = -1;
+ goto end;
+ }
+ if (cmsg->cmsg_type == SCM_RIGHTS) {
+ /*
+ * We found the controle message for file descriptors,
+ * now copy the fds to the fds ptr and return success.
+ */
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
+ fprintf(stderr, "Error: Received %zu bytes of"
+ "ancillary data for FDs, 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;
+ goto end;
+ }
+#ifdef __linux__
+ if (cmsg->cmsg_type == SCM_CREDENTIALS) {
+ /*
+ * Expect credentials to be sent when expecting fds even
+ * if no credential were include in the send(). The
+ * kernel adds them...
+ */
+ ret = -1;
+ }
+#endif /* __linux__ */
+ }
+end:
+ return ret;
+}
+
+static
+void close_raw_fd(void *ptr)
+{
+ const int raw_fd = *((const int *) ptr);
+
+ if (raw_fd >= 0) {
+ const int ret = close(raw_fd);
+
+ if (ret) {
+ PERROR("Failed to close file descriptor %d", raw_fd);
+ }
+ }
+}
+
+static
+enum lttng_error_code add_fds_to_payload(struct lttng_dynamic_array *raw_fds,
+ struct lttng_payload *payload)
+{
+ int i;
+ enum lttng_error_code ret_code = LTTNG_OK;
+ const int fd_count = lttng_dynamic_array_get_count(raw_fds);
+
+ for (i = 0; i < fd_count; i++) {
+ int ret;
+ struct fd_handle *handle;
+ int *raw_fd = (int *) lttng_dynamic_array_get_element(
+ raw_fds, i);
+
+ LTTNG_ASSERT(*raw_fd != -1);
+
+ handle = fd_handle_create(*raw_fd);
+ if (!handle) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* FD ownership transferred to the handle. */
+ *raw_fd = -1;
+
+ ret = lttng_payload_push_fd_handle(payload, handle);
+ fd_handle_put(handle);
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+end:
+ return ret_code;
+}
+
+static
+ssize_t _lttcomm_recv_payload_fds_unix_sock(int sock, size_t nb_fd,
+ struct lttng_payload *payload, bool blocking)
+{
+ int i = 0;
+ enum lttng_error_code add_ret;
+ ssize_t ret;
+ int default_value = -1;
+ struct lttng_dynamic_array raw_fds;
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(payload);
+ LTTNG_ASSERT(nb_fd > 0);
+
+ lttng_dynamic_array_init(&raw_fds, sizeof(int), close_raw_fd);
+
+ for (i = 0; i < nb_fd; i++) {
+ if (lttng_dynamic_array_add_element(&raw_fds, &default_value)) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ if (blocking) {
+ ret = lttcomm_recv_fds_unix_sock(
+ sock, (int *) raw_fds.buffer.data, nb_fd);
+ } else {
+ ret = lttcomm_recv_fds_unix_sock_non_block(
+ sock, (int *) raw_fds.buffer.data, nb_fd);
+ }
+
+ if (ret <= 0) {
+ goto end;
+ }
+
+ add_ret = add_fds_to_payload(&raw_fds, payload);
+ if (add_ret != LTTNG_OK) {
+ ret = - (int) add_ret;
+ goto end;
+ }
+
+end:
+ lttng_dynamic_array_reset(&raw_fds);
+ return ret;
+}
+
+ssize_t lttcomm_recv_payload_fds_unix_sock(int sock, size_t nb_fd,
+ struct lttng_payload *payload)
+{
+ return _lttcomm_recv_payload_fds_unix_sock(sock, nb_fd, payload, true);
+}
+
+ssize_t lttcomm_recv_payload_fds_unix_sock_non_block(int sock, size_t nb_fd,
+ struct lttng_payload *payload)
+{
+ return _lttcomm_recv_payload_fds_unix_sock(sock, nb_fd, payload, false);
+}
+
+/*
+ * Recv a message accompanied by fd(s) from a non-blocking unix socket.
+ * Only use with non-blocking sockets.
+ *
+ * Returns the size of received data, or negative error value.
+ *
+ * Expect at most "nb_fd" file descriptors.
+ *
+ * Note that based on our comprehension, partial reception of fds is not
+ * possible since the FDs are actually in the control message. It is all or
+ * nothing, still the sender side can send the wrong number of fds.
+ */
+ssize_t lttcomm_recv_fds_unix_sock_non_block(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);
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(fds);
+ LTTNG_ASSERT(nb_fd > 0);
+
+#ifdef __linux__
+/* Account for the struct ucred cmsg in the buffer size */
+#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
+#else
+#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
+#endif /* __linux__ */
+
+ char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE];
+ 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;
+
+ cmsg = (struct cmsghdr *) recv_buf;
+ cmsg->cmsg_len = CMSG_LEN(sizeof_fds);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+
+ msg.msg_control = cmsg;
+ msg.msg_controllen = CMSG_LEN(sizeof(recv_buf));
+ msg.msg_flags = 0;
+
+retry:
+ ret = lttng_recvmsg_nosigpipe(sock, &msg);
+ if (ret < 0) {
+ if (errno == EINTR) {
+ goto retry;
+ } else {
+ /*
+ * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
+ */
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ /*
+ * This can happen in non blocking mode.
+ * Nothing was recv.
+ */
+ ret = 0;
+ goto end;
+ }
+
+ if (errno == EPIPE) {
+ /* Expected error, pass error to caller */
+ DBG3("EPIPE on recvmsg");
+ ret = -1;
+ goto end;
+ }
+
+ /* Unexpected error */
+ PERROR("recvmsg");
+ ret = -1;
+ 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;
+ }
+
+ /*
+ * If the socket was configured with SO_PASSCRED, the kernel will add a
+ * control message (cmsg) to the ancillary data of the unix socket. We
+ * need to expect a cmsg of the SCM_CREDENTIALS as the first control
+ * message.
+ */
+ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+ if (cmsg->cmsg_level != SOL_SOCKET) {
+ fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n");
+ ret = -1;
+ goto end;
+ }
+ if (cmsg->cmsg_type == SCM_RIGHTS) {
+ /*
+ * We found the controle message for file descriptors,
+ * now copy the fds to the fds ptr and return success.
+ */
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
+ fprintf(stderr, "Error: Received %zu bytes of"
+ "ancillary data for FDs, 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;
+ goto end;
+ }
+#ifdef __linux__
+ if (cmsg->cmsg_type == SCM_CREDENTIALS) {
+ /*
+ * Expect credentials to be sent when expecting fds even
+ * if no credential were include in the send(). The
+ * kernel adds them...
+ */
+ ret = -1;
+ }
+#endif /* __linux__ */
+ }
+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, const void *buf, size_t len)
+{
+ struct msghdr msg;
+ struct iovec iov[1];
+ ssize_t ret = -1;
+#if defined(__linux__) || defined(__CYGWIN__)
+ struct cmsghdr *cmptr;
+ size_t sizeof_cred = sizeof(lttng_sock_cred);
+ char anc_buf[CMSG_SPACE(sizeof_cred)];
+ lttng_sock_cred *creds;
+
+ memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
+#endif /* __linux__, __CYGWIN__ */
+
+ memset(&msg, 0, sizeof(msg));
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(buf);
+ LTTNG_ASSERT(len > 0);
+
+ iov[0].iov_base = (void *) buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+#if defined(__linux__) || defined(__CYGWIN__)
+ msg.msg_control = (caddr_t) anc_buf;
+ msg.msg_controllen = CMSG_LEN(sizeof_cred);
+
+ cmptr = CMSG_FIRSTHDR(&msg);
+ if (!cmptr) {
+ return -1;
+ }
+ 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__, __CYGWIN__ */
+
+ 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;
+ size_t len_last;
+#if defined(__linux__) || defined(__CYGWIN__)
+ struct cmsghdr *cmptr;
+ size_t sizeof_cred = sizeof(lttng_sock_cred);
+ char anc_buf[CMSG_SPACE(sizeof_cred)];
+#endif /* __linux__, __CYGWIN__ */
+
+ LTTNG_ASSERT(sock);
+ LTTNG_ASSERT(buf);
+ LTTNG_ASSERT(len > 0);
+ LTTNG_ASSERT(creds);
+
+ memset(&msg, 0, sizeof(msg));
+
+ /* Prepare to receive the structures */
+ iov[0].iov_base = buf;
+ iov[0].iov_len = len;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+#if defined(__linux__) || defined(__CYGWIN__)
+ msg.msg_control = anc_buf;
+ msg.msg_controllen = sizeof(anc_buf);
+#endif /* __linux__, __CYGWIN__ */
+
+ do {
+ len_last = iov[0].iov_len;
+ ret = recvmsg(sock, &msg, 0);
+ if (ret > 0) {
+ iov[0].iov_base = (char *) iov[0].iov_base + ret;
+ iov[0].iov_len -= ret;
+ LTTNG_ASSERT(ret <= len_last);
+ }
+ } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
+ if (ret < 0) {
+ PERROR("recvmsg fds");
+ goto end;
+ } else if (ret > 0) {
+ ret = len;
+ }
+ /* Else ret = 0 meaning an orderly shutdown. */
+
+#if defined(__linux__) || defined(__CYGWIN__)
+ 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(__sun__) || defined(__APPLE__))
+ if (lttng_get_unix_socket_peer_creds(sock, creds)) {
+ fprintf(stderr, "ARG\n");
+ ret = -1;
+ goto end;
+ }
+#else
+#error "Please implement credential support for your OS."
+#endif /* __linux__, __CYGWIN__ */
+
+end:
+ return ret;
+}
+
+/*
+ * Set socket option to use credentials passing.
+ */
+#if defined(__linux__) || defined(__CYGWIN__)
+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(__sun__) || defined(__APPLE__))
+int lttcomm_setsockopt_creds_unix_sock(int sock)
+{
+ return 0;
+}
+#else
+#error "Please implement credential support for your OS."
+#endif /* __linux__ */
projects / lttng-tools.git / blobdiff