From b0a99af43c7ab2159f14adc4e6f382bb56612286 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 26 Sep 2011 11:28:57 -0400 Subject: [PATCH] Add ust basic tracing implementation Signed-off-by: Mathieu Desnoyers --- tests/ust-basic-tracing/Makefile.am | 6 + tests/ust-basic-tracing/ust-basic-tracing.c | 978 ++++++++++++++++++++ 2 files changed, 984 insertions(+) create mode 100644 tests/ust-basic-tracing/Makefile.am create mode 100644 tests/ust-basic-tracing/ust-basic-tracing.c diff --git a/tests/ust-basic-tracing/Makefile.am b/tests/ust-basic-tracing/Makefile.am new file mode 100644 index 0000000..676ae2e --- /dev/null +++ b/tests/ust-basic-tracing/Makefile.am @@ -0,0 +1,6 @@ +AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/libust + +noinst_PROGRAMS = ust-basic-tracing +ust_basic_tracing_SOURCES = ust-basic-tracing.c +ust_basic_tracing_LDADD = $(top_builddir)/liblttng-ust-comm/liblttng-ust-comm.la \ + $(top_builddir)/libringbuffer/libringbuffer.la diff --git a/tests/ust-basic-tracing/ust-basic-tracing.c b/tests/ust-basic-tracing/ust-basic-tracing.c new file mode 100644 index 0000000..437b9c2 --- /dev/null +++ b/tests/ust-basic-tracing/ust-basic-tracing.c @@ -0,0 +1,978 @@ +/* + * ust-basic-tracing.c - Basic single-session, single-channel, single-process UST tracing + * + * Copyright (C) 2011 - Mathieu Desnoyers + * Copyright (C) 2011 - David Goulet + * + * 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; only version 2 of the License. + * + * 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., 59 Temple + * Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#define _LARGEFILE64_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "lttng-ust-comm.h" +#include "../../libringbuffer/backend.h" +#include "../../libringbuffer/frontend.h" + +#define MAX_NR_STREAMS 64 +#define MAX_NR_EVENTS 128 + +struct object_data { + int handle; + int shm_fd; + int wait_fd; + uint64_t memory_map_size; +}; + +static int session_handle; +static struct object_data metadata_stream_data; +static struct object_data metadata_data; +static struct object_data channel_data; +static struct object_data stream_data[MAX_NR_STREAMS]; +static int event_handle[MAX_NR_EVENTS]; + +static int apps_socket = -1; +static char apps_sock_path[PATH_MAX]; +static char local_apps_wait_shm_path[PATH_MAX]; + +static volatile int quit_program; + +static void handle_signals(int signo) +{ + quit_program = 1; +} + +static int send_app_msg(int sock, struct lttcomm_ust_msg *lum) +{ + ssize_t len; + + len = lttcomm_send_unix_sock(sock, lum, sizeof(*lum)); + switch (len) { + case sizeof(*lum): + printf("message successfully sent\n"); + break; + case -1: + if (errno == ECONNRESET) { + printf("remote end closed connection\n"); + return 0; + } + return -1; + default: + printf("incorrect message size: %zd\n", len); + return -1; + } + return 0; +} + +static int recv_app_reply(int sock, struct lttcomm_ust_reply *lur, + uint32_t expected_handle, uint32_t expected_cmd) +{ + ssize_t len; + + memset(lur, 0, sizeof(*lur)); + len = lttcomm_recv_unix_sock(sock, lur, sizeof(*lur)); + switch (len) { + case 0: /* orderly shutdown */ + printf("Application has performed an orderly shutdown\n"); + return -EINVAL; + case sizeof(*lur): + printf("result message received\n"); + if (lur->handle != expected_handle) { + printf("Unexpected result message handle\n"); + return -EINVAL; + } + + if (lur->cmd != expected_cmd) { + printf("Unexpected result message command\n"); + return -EINVAL; + } + if (lur->ret_code != LTTCOMM_OK) { + printf("remote operation failed with code %d.\n", + lur->ret_code); + return lur->ret_code; + } + return 0; + case -1: + if (errno == ECONNRESET) { + printf("remote end closed connection\n"); + return -EINVAL; + } + return -1; + default: + printf("incorrect message size: %zd\n", len); + return len > 0 ? -1 : len; + } +} + +static int send_app_cmd(int sock, + struct lttcomm_ust_msg *lum, + struct lttcomm_ust_reply *lur) +{ + int ret; + + ret = send_app_msg(sock, lum); + if (ret) + return ret; + ret = recv_app_reply(sock, lur, lum->handle, lum->cmd); + if (ret) + return ret; + return 0; +} + + +/* + * Receives a single fd from socket. + * + * Returns the size of received data + */ +static int lttcomm_recv_fd(int sock) +{ + struct iovec iov[1]; + int ret = 0; + int data_fd; + struct cmsghdr *cmsg; + char recv_fd[CMSG_SPACE(sizeof(int))]; + struct msghdr msg = { 0 }; + + /* Prepare to receive the structures */ + iov[0].iov_base = &data_fd; + iov[0].iov_len = sizeof(data_fd); + msg.msg_iov = iov; + msg.msg_iovlen = 1; + msg.msg_control = recv_fd; + msg.msg_controllen = sizeof(recv_fd); + + printf("Waiting to receive fd\n"); + if ((ret = recvmsg(sock, &msg, 0)) < 0) { + perror("recvmsg"); + goto end; + } + if (ret != sizeof(data_fd)) { + printf("Received %d bytes, expected %ld", ret, sizeof(data_fd)); + goto end; + } + cmsg = CMSG_FIRSTHDR(&msg); + if (!cmsg) { + printf("Invalid control message header\n"); + ret = -1; + goto end; + } + if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) { + printf("Didn't received any fd\n"); + ret = -1; + goto end; + } + /* this is our fd */ + ret = ((int *) CMSG_DATA(cmsg))[0]; + printf("received fd %d\n", ret); +end: + return ret; +} + + +static +int open_streams(int sock, int channel_handle, struct object_data *stream_datas, + int nr_check) +{ + int ret, k = 0; + + for (;;) { + struct lttcomm_ust_msg lum; + struct lttcomm_ust_reply lur; + + memset(&lum, 0, sizeof(lum)); + lum.handle = channel_handle; + lum.cmd = LTTNG_UST_STREAM; + ret = send_app_cmd(sock, &lum, &lur); + if (!ret) { + assert(k < nr_check); + stream_datas[k].handle = lur.ret_val; + printf("received stream handle %u\n", + stream_datas[k].handle); + if (lur.ret_code == LTTCOMM_OK) { + ssize_t len; + + stream_datas[k].memory_map_size = lur.u.stream.memory_map_size; + /* get shm fd */ + len = lttcomm_recv_fd(sock); + if (len < 0) + return -EINVAL; + stream_datas[k].shm_fd = len; + /* get wait fd */ + len = lttcomm_recv_fd(sock); + if (len < 0) + return -EINVAL; + stream_datas[k].wait_fd = len; + } + k++; + } + if (ret == -ENOENT) + break; + if (ret) + return ret; + } + return 0; +} + +static +int close_streams(int sock, struct object_data *stream_datas, int nr_check) +{ + int ret, k; + + for (k = 0; k < nr_check; k++) { + struct lttcomm_ust_msg lum; + struct lttcomm_ust_reply lur; + + if (!stream_datas[k].handle) + continue; + memset(&lum, 0, sizeof(lum)); + lum.handle = stream_datas[k].handle; + lum.cmd = LTTNG_UST_RELEASE; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) { + printf("Error closing stream\n"); + return ret; + } + if (stream_datas[k].shm_fd >= 0) { + ret = close(stream_datas[k].shm_fd); + if (ret) { + printf("Error closing stream shm_fd\n"); + return ret; + } + } + if (stream_datas[k].wait_fd >= 0) { + ret = close(stream_datas[k].wait_fd); + if (ret) { + printf("Error closing stream wait_fd\n"); + return ret; + } + } + } + return 0; +} + +static +struct shm_handle *map_channel(struct object_data *chan_data, + struct object_data *stream_datas, int nr_check) +{ + struct shm_handle *handle; + struct channel *chan; + int k, ret; + + /* map metadata channel */ + handle = channel_handle_create(chan_data->shm_fd, + chan_data->wait_fd, + chan_data->memory_map_size); + if (!handle) { + printf("create handle error\n"); + return NULL; + } + chan_data->shm_fd = -1; + chan_data->wait_fd = -1; + chan = shmp(handle, handle->chan); + + for (k = 0; k < nr_check; k++) { + struct object_data *stream_data = &stream_datas[k]; + + if (!stream_data->handle) + break; + /* map stream */ + ret = channel_handle_add_stream(handle, + stream_data->shm_fd, + stream_data->wait_fd, + stream_data->memory_map_size); + if (ret) { + printf("add stream error\n"); + goto error_destroy; + } + stream_data->shm_fd = -1; + stream_data->wait_fd = -1; + } + return handle; + +error_destroy: + channel_destroy(chan, handle, 1); + return NULL; +} + +static +void unmap_channel(struct shm_handle *handle) +{ + struct channel *chan; + + chan = shmp(handle, handle->chan); + /* unmap channel */ + channel_destroy(chan, handle, 1); +} + +static +int consume_stream(struct shm_handle *handle, int cpu, char *outfile) +{ + struct channel *chan; + struct lib_ring_buffer *buf; + int outfd, ret; + int shm_fd, wait_fd; + uint64_t memory_map_size; + + chan = shmp(handle, handle->chan); + + /* open stream */ + buf = channel_get_ring_buffer(&chan->backend.config, + chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size); + if (!buf) + return -ENOENT; + ret = lib_ring_buffer_open_read(buf, handle, 1); + if (ret) { + return -1; + } + + /* copy */ + outfd = open(outfile, O_WRONLY | O_CREAT | O_LARGEFILE | O_TRUNC, + S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); + if (outfd < 0) { + perror("open output"); + return -1; + } + + printf("Waiting for buffer data for %s\n", outfile); + for (;;) { + unsigned long read_size; + unsigned long copy_size; + char *ptr; + + ret = lib_ring_buffer_get_next_subbuf(buf, handle); + printf("get next ret %d\n", ret); + if (ret == -ENODATA) + break; + if (ret == -EAGAIN) { + sleep(1); + continue; + } + if (ret) { + printf("Error %d in lib_ring_buffer_get_next_subbuf\n", ret); + return -1; + } + read_size = lib_ring_buffer_get_read_data_size( + &chan->backend.config, buf, handle); + read_size = PAGE_ALIGN(read_size); + ptr = lib_ring_buffer_read_offset_address( + &buf->backend, 0, handle); + printf("WRITE: copy %lu bytes\n", read_size); + copy_size = write(outfd, ptr, read_size); + if (copy_size < read_size) { + printf("write issue: copied %zd, expected %lu\n", copy_size, read_size); + } + lib_ring_buffer_put_next_subbuf(buf, handle); + } + + ret = close(outfd); + if (ret) { + perror("close"); + return -1; + } + + /* close stream */ + lib_ring_buffer_release_read(buf, handle, 1); + return 0; +} + +static +int consume_buffers(const char *outputpath) +{ + int k, ret; + mode_t old_umask; + char pathname[PATH_MAX]; + struct shm_handle *handle; + + snprintf(pathname, PATH_MAX - 1, "%s", outputpath); + old_umask = umask(0); + ret = mkdir(pathname, S_IRWXU | S_IRWXG); + if (ret && errno != EEXIST) { + perror("mkdir"); + umask(old_umask); + return -1; + } + umask(old_umask); + + /* copy metadata */ + handle = map_channel(&metadata_data, + &metadata_stream_data, 1); + if (!handle) + return -1; + snprintf(pathname, PATH_MAX - 1, + "%s/metadata", outputpath); + ret = consume_stream(handle, -1, pathname); + if (ret && ret != -ENOENT) { + printf("Error in consume_stream\n"); + return ret; + } + unmap_channel(handle); + + /* copy binary data */ + handle = map_channel(&channel_data, + stream_data, MAX_NR_STREAMS); + if (!handle) + return -1; + for (k = 0; k < MAX_NR_STREAMS; k++) { + snprintf(pathname, PATH_MAX - 1, + "%s/data_%u", outputpath, k); + ret = consume_stream(handle, k, pathname); + if (ret && ret != -ENOENT) { + printf("Error in consume_stream\n"); + return ret; + } + } + unmap_channel(handle); + + return 0; +} + +int send_app_msgs(int sock, const char *outputpath, + unsigned int nr_events, const char **event_names) +{ + struct lttcomm_ust_msg lum; + struct lttcomm_ust_reply lur; + int ret, k; + + /* Create session */ + memset(&lum, 0, sizeof(lum)); + lum.handle = LTTNG_UST_ROOT_HANDLE; + lum.cmd = LTTNG_UST_SESSION; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + session_handle = lur.ret_val; + printf("received session handle %u\n", session_handle); + + /* Create metadata channel */ + memset(&lum, 0, sizeof(lum)); + lum.handle = session_handle; + lum.cmd = LTTNG_UST_METADATA; + lum.u.channel.overwrite = 0; + lum.u.channel.subbuf_size = 32768; + lum.u.channel.num_subbuf = 4; + lum.u.channel.switch_timer_interval = 0; + lum.u.channel.read_timer_interval = 0; + lum.u.channel.output = LTTNG_UST_MMAP; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + metadata_data.handle = lur.ret_val; + printf("received metadata handle %u\n", metadata_data.handle); + if (lur.ret_code == LTTCOMM_OK) { + ssize_t len; + + metadata_data.memory_map_size = lur.u.channel.memory_map_size; + /* get shm fd */ + len = lttcomm_recv_fd(sock); + if (len < 0) + return -EINVAL; + metadata_data.shm_fd = len; + /* get wait fd */ + len = lttcomm_recv_fd(sock); + if (len < 0) + return -EINVAL; + metadata_data.wait_fd = len; + } + + ret = open_streams(sock, metadata_data.handle, + &metadata_stream_data, 1); + if (ret) { + printf("Error in open_streams\n"); + return ret; + } + + /* Create data channel */ + memset(&lum, 0, sizeof(lum)); + lum.handle = session_handle; + lum.cmd = LTTNG_UST_CHANNEL; + //lum.u.channel.overwrite = 0; + lum.u.channel.overwrite = 1; + lum.u.channel.subbuf_size = 32768; + lum.u.channel.num_subbuf = 8; + //lum.u.channel.num_subbuf = 4; + //lum.u.channel.num_subbuf = 2; + lum.u.channel.switch_timer_interval = 0; + lum.u.channel.read_timer_interval = 0; + lum.u.channel.output = LTTNG_UST_MMAP; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + channel_data.handle = lur.ret_val; + printf("received channel handle %u\n", channel_data.handle); + if (lur.ret_code == LTTCOMM_OK) { + ssize_t len; + + channel_data.memory_map_size = lur.u.channel.memory_map_size; + /* get shm fd */ + len = lttcomm_recv_fd(sock); + if (len < 0) + return -EINVAL; + channel_data.shm_fd = len; + /* get wait fd */ + len = lttcomm_recv_fd(sock); + if (len < 0) + return -EINVAL; + channel_data.wait_fd = len; + } + + /* Create events */ + for (k = 0; k < nr_events; k++) { + memset(&lum, 0, sizeof(lum)); + lum.handle = channel_data.handle; + lum.cmd = LTTNG_UST_EVENT; + strncpy(lum.u.event.name, event_names[k], + LTTNG_UST_SYM_NAME_LEN); + lum.u.event.instrumentation = LTTNG_UST_TRACEPOINT; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + event_handle[k] = lur.ret_val; + printf("received event handle %u\n", event_handle[k]); + } + + /* Get references to channel streams */ + ret = open_streams(sock, channel_data.handle, + stream_data, MAX_NR_STREAMS); + if (ret) { + printf("Error in open_streams\n"); + return ret; + } + + memset(&lum, 0, sizeof(lum)); + lum.handle = session_handle; + lum.cmd = LTTNG_UST_SESSION_START; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + printf("Session handle %u started.\n", session_handle); + + /* Tell application registration is done */ + memset(&lum, 0, sizeof(lum)); + lum.handle = LTTNG_UST_ROOT_HANDLE; + lum.cmd = LTTNG_UST_REGISTER_DONE; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + printf("Registration done acknowledged.\n"); + + sleep(4); + + ret = consume_buffers(outputpath); + if (ret) { + printf("Error in consume_buffers\n"); + return ret; + } + + /* Release data channel */ + /* Release streams */ + ret = close_streams(sock, stream_data, + MAX_NR_STREAMS); + if (ret) + return ret; + + /* Release events */ + for (k = 0; k < nr_events; k++) { + memset(&lum, 0, sizeof(lum)); + lum.handle = event_handle[k]; + lum.cmd = LTTNG_UST_RELEASE; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + } + memset(&lum, 0, sizeof(lum)); + lum.handle = channel_data.handle; + lum.cmd = LTTNG_UST_RELEASE; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + if (channel_data.shm_fd >= 0) { + ret = close(channel_data.shm_fd); + if (ret) + return ret; + } + if (channel_data.wait_fd >= 0) { + ret = close(channel_data.wait_fd); + if (ret) + return ret; + } + + /* Release metadata channel */ + ret = close_streams(sock, &metadata_stream_data, 1); + if (ret) + return ret; + + memset(&lum, 0, sizeof(lum)); + lum.handle = metadata_data.handle; + lum.cmd = LTTNG_UST_RELEASE; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + if (metadata_data.shm_fd >= 0) { + ret = close(metadata_data.shm_fd); + if (ret) + return ret; + } + if (metadata_data.wait_fd >= 0) { + ret = close(metadata_data.wait_fd); + if (ret) + return ret; + } + + /* Release session */ + memset(&lum, 0, sizeof(lum)); + lum.handle = session_handle; + lum.cmd = LTTNG_UST_RELEASE; + ret = send_app_cmd(sock, &lum, &lur); + if (ret) + return ret; + + return 0; +} + +/* + * Using fork to set umask in the child process (not multi-thread safe). We + * deal with the shm_open vs ftruncate race (happening when the sessiond owns + * the shm and does not let everybody modify it, to ensure safety against + * shm_unlink) by simply letting the mmap fail and retrying after a few + * seconds. For global shm, everybody has rw access to it until the sessiond + * starts. + */ +static int get_wait_shm(char *shm_path, size_t mmap_size, int global) +{ + int wait_shm_fd, ret; + mode_t mode; + + /* Default permissions */ + mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; + + /* Change owner of the shm path */ + if (global) { + ret = chown(shm_path, 0, 0); + if (ret < 0) { + if (errno != ENOENT) { + perror("chown wait shm"); + goto error; + } + } + + /* + * If global session daemon, any application can register so the shm + * needs to be set in read-only mode for others. + */ + mode |= S_IROTH; + } else { + ret = chown(shm_path, getuid(), getgid()); + if (ret < 0) { + if (errno != ENOENT) { + perror("chown wait shm"); + goto error; + } + } + } + + /* + * Set permissions to the shm even if we did not create the shm. + */ + ret = chmod(shm_path, mode); + if (ret < 0) { + if (errno != ENOENT) { + perror("chmod wait shm"); + goto error; + } + } + + /* + * We're alone in a child process, so we can modify the process-wide + * umask. + */ + umask(~mode); + + /* + * Try creating shm (or get rw access). We don't do an exclusive open, + * because we allow other processes to create+ftruncate it concurrently. + */ + wait_shm_fd = shm_open(shm_path, O_RDWR | O_CREAT, mode); + if (wait_shm_fd < 0) { + perror("shm_open wait shm"); + goto error; + } + + ret = ftruncate(wait_shm_fd, mmap_size); + if (ret < 0) { + perror("ftruncate wait shm"); + exit(EXIT_FAILURE); + } + + ret = fchmod(wait_shm_fd, mode); + if (ret < 0) { + perror("fchmod"); + exit(EXIT_FAILURE); + } + + printf("Got the wait shm fd %d\n", wait_shm_fd); + + return wait_shm_fd; + +error: + printf("Failing to get the wait shm fd\n"); + + return -1; +} + +int update_futex(int fd, int active) +{ + size_t mmap_size = sysconf(_SC_PAGE_SIZE); + char *wait_shm_mmap; + int ret; + + wait_shm_mmap = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + if (wait_shm_mmap == MAP_FAILED) { + perror("mmap"); + goto error; + } + + if (active) { + uatomic_set((int32_t *) wait_shm_mmap, 1); + futex_async((int32_t *) wait_shm_mmap, FUTEX_WAKE, + INT_MAX, NULL, NULL, 0); + } else { + uatomic_set((int32_t *) wait_shm_mmap, 0); + } + ret = munmap(wait_shm_mmap, mmap_size); + if (ret) { + perror("Error unmapping wait shm"); + goto error; + } + return 0; +error: + return -1; +} + +/* + * Set open files limit to unlimited. This daemon can open a large number of + * file descriptors in order to consumer multiple kernel traces. + */ +static void set_ulimit(void) +{ + int ret; + struct rlimit lim; + + /* + * If not root, we cannot increase our max open files. But our + * scope is then limited to processes from a single user. + */ + if (getuid() != 0) + return; + /* The kernel does not allowed an infinite limit for open files */ + lim.rlim_cur = 65535; + lim.rlim_max = 65535; + + ret = setrlimit(RLIMIT_NOFILE, &lim); + if (ret < 0) { + perror("failed to set open files limit"); + } +} + +/* + * Usage: + * ./ust-basic-tracing outputpath event_name1 event_name2 .... + */ +int main(int argc, const char **argv) +{ + const char *home_dir; + int ret, wait_shm_fd; + struct sigaction act; + mode_t old_umask; + const char *outputpath; + const char **event_names; + unsigned int nr_events; + + if (argc < 2) { + printf("Usage:\n"); + printf("%s outputpath event_name1 event_name2 ...\n", + argv[0]); + exit(-1); + } + outputpath = argv[1]; + event_names = &argv[2]; + nr_events = argc - 2; + + set_ulimit(); + + /* Ignore sigpipe */ + memset(&act, 0, sizeof(act)); + ret = sigemptyset(&act.sa_mask); + if (ret == -1) { + perror("sigemptyset"); + return -1; + } + + act.sa_handler = SIG_IGN; + ret = sigaction(SIGPIPE, &act, NULL); + if (ret == -1) { + perror("sigaction"); + return -1; + } + + /* Handle SIGTERM */ + act.sa_handler = handle_signals; + ret = sigaction(SIGTERM, &act, NULL); + if (ret == -1) { + perror("sigaction"); + return -1; + } + /* Handle SIGINT */ + ret = sigaction(SIGINT, &act, NULL); + if (ret == -1) { + perror("sigaction"); + return -1; + } + + if (geteuid() == 0) { + ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH); + if (ret && errno != EEXIST) { + perror("mkdir"); + return -1; + } + wait_shm_fd = get_wait_shm(DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH, + sysconf(_SC_PAGE_SIZE), 1); + if (wait_shm_fd < 0) { + perror("global wait shm error"); + return -1; + } + strcpy(apps_sock_path, DEFAULT_GLOBAL_APPS_UNIX_SOCK); + old_umask = umask(0); + } else { + snprintf(local_apps_wait_shm_path, PATH_MAX, + DEFAULT_HOME_APPS_WAIT_SHM_PATH, getuid()); + wait_shm_fd = get_wait_shm(local_apps_wait_shm_path, + sysconf(_SC_PAGE_SIZE), 0); + if (wait_shm_fd < 0) { + perror("local wait shm error"); + return -1; + } + home_dir = (const char *) getenv("HOME"); + if (!home_dir) { + perror("getenv error"); + return -ENOENT; + } + snprintf(apps_sock_path, PATH_MAX, + DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); + } + + ret = lttcomm_create_unix_sock(apps_sock_path); + if (ret < 0) { + perror("create error"); + return ret; + } + apps_socket = ret; + + if (getuid() == 0) { + /* File permission MUST be 666 */ + ret = chmod(apps_sock_path, + S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); + if (ret < 0) { + printf("Set file permissions failed: %s\n", apps_sock_path); + perror("chmod"); + goto end; + } + umask(old_umask); + } + ret = lttcomm_listen_unix_sock(apps_socket); + if (ret < 0) { + perror("listen error"); + return ret; + } + + /* wake up futexes */ + ret = update_futex(wait_shm_fd, 1); + if (ret) { + fprintf(stderr, "Error wakeup futex\n"); + return -1; + } + + for (;;) { + int sock; + ssize_t len; + struct { + uint32_t major; + uint32_t minor; + pid_t pid; + pid_t ppid; + uid_t uid; + gid_t gid; + char name[16]; /* Process name */ + } reg_msg; + char bufname[17]; + + if (quit_program) + break; + + printf("Accepting application registration\n"); + sock = lttcomm_accept_unix_sock(apps_socket); + if (sock < 0) { + perror("accept error"); + goto end; + } + + /* + * Basic recv here to handle the very simple data + * that the libust send to register (reg_msg). + */ + len = lttcomm_recv_unix_sock(sock, ®_msg, sizeof(reg_msg)); + if (len < 0 || len != sizeof(reg_msg)) { + perror("lttcomm_recv_unix_sock"); + continue; + } + memcpy(bufname, reg_msg.name, 16); + bufname[16] = '\0'; + printf("Application %s pid %u ppid %u uid %u gid %u has registered (version : %u.%u)\n", + bufname, reg_msg.pid, reg_msg.ppid, reg_msg.uid, + reg_msg.gid, reg_msg.major, reg_msg.minor); + ret = send_app_msgs(sock, outputpath, nr_events, event_names); + if (ret) { + printf("Error in send_app_msgs.\n"); + sleep(1); + } + close(sock); + } + +end: + printf("quitting.\n"); + /* Let applications know we are not responding anymore */ + ret = update_futex(wait_shm_fd, 0); + if (ret) { + fprintf(stderr, "Error wakeup futex\n"); + return -1; + } + + return 0; +} -- 2.34.1