-/*
- * 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 += 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 += 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 += 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