--- /dev/null
+/* lttd
+ *
+ * Linux Trace Toolkit Daemon
+ *
+ * This is a simple daemon that reads a few relayfs channels and save them in a
+ * trace.
+ *
+ *
+ * Copyright 2005 -
+ * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/poll.h>
+#include <sys/mman.h>
+#include <signal.h>
+
+/* Relayfs IOCTL */
+#include <asm/ioctl.h>
+#include <asm/types.h>
+
+/* Get the next sub buffer that can be read. */
+#define RELAYFS_GET_SUBBUF _IOR(0xF4, 0x00,__u32)
+/* Release the oldest reserved (by "get") sub buffer. */
+#define RELAYFS_PUT_SUBBUF _IO(0xF4, 0x01)
+/* returns the number of sub buffers in the per cpu channel. */
+#define RELAYFS_GET_N_SUBBUFS _IOR(0xF4, 0x02,__u32)
+/* returns the size of the sub buffers. */
+#define RELAYFS_GET_SUBBUF_SIZE _IOR(0xF4, 0x03,__u32)
+
+
+
+enum {
+ GET_SUBBUF,
+ PUT_SUBBUF,
+ GET_N_BUBBUFS,
+ GET_SUBBUF_SIZE
+};
+
+struct fd_pair {
+ int channel;
+ int trace;
+ unsigned int n_subbufs;
+ unsigned int subbuf_size;
+ void *mmap;
+};
+
+struct channel_trace_fd {
+ struct fd_pair *pair;
+ int num_pairs;
+};
+
+static char *trace_name = NULL;
+static char *channel_name = NULL;
+static int daemon_mode = 0;
+static int append_mode = 0;
+volatile static int quit_program = 0; /* For signal handler */
+
+/* Args :
+ *
+ * -t directory Directory name of the trace to write to. Will be created.
+ * -c directory Root directory of the relayfs trace channels.
+ * -d Run in background (daemon).
+ * -a Trace append mode.
+ * -s Send SIGUSR1 to parent when ready for IO.
+ */
+void show_arguments(void)
+{
+ printf("Please use the following arguments :\n");
+ printf("\n");
+ printf("-t directory Directory name of the trace to write to.\n"
+ " It will be created.\n");
+ printf("-c directory Root directory of the relayfs trace channels.\n");
+ printf("-d Run in background (daemon).\n");
+ printf("-a Append to an possibly existing trace.\n");
+ printf("\n");
+}
+
+
+/* parse_arguments
+ *
+ * Parses the command line arguments.
+ *
+ * Returns 1 if the arguments were correct, but doesn't ask for program
+ * continuation. Returns -1 if the arguments are incorrect, or 0 if OK.
+ */
+int parse_arguments(int argc, char **argv)
+{
+ int ret = 0;
+ int argn = 1;
+
+ if(argc == 2) {
+ if(strcmp(argv[1], "-h") == 0) {
+ return 1;
+ }
+ }
+
+ while(argn < argc) {
+
+ switch(argv[argn][0]) {
+ case '-':
+ switch(argv[argn][1]) {
+ case 't':
+ if(argn+1 < argc) {
+ trace_name = argv[argn+1];
+ argn++;
+ }
+ break;
+ case 'c':
+ if(argn+1 < argc) {
+ channel_name = argv[argn+1];
+ argn++;
+ }
+ break;
+ case 'd':
+ daemon_mode = 1;
+ break;
+ case 'a':
+ append_mode = 1;
+ break;
+ default:
+ printf("Invalid argument '%s'.\n", argv[argn]);
+ printf("\n");
+ ret = -1;
+ }
+ break;
+ default:
+ printf("Invalid argument '%s'.\n", argv[argn]);
+ printf("\n");
+ ret = -1;
+ }
+ argn++;
+ }
+
+ if(trace_name == NULL) {
+ printf("Please specify a trace name.\n");
+ printf("\n");
+ ret = -1;
+ }
+
+ if(channel_name == NULL) {
+ printf("Please specify a channel name.\n");
+ printf("\n");
+ ret = -1;
+ }
+
+ return ret;
+}
+
+void show_info(void)
+{
+ printf("Linux Trace Toolkit Trace Daemon\n");
+ printf("\n");
+ printf("Reading from relayfs directory : %s\n", channel_name);
+ printf("Writing to trace directory : %s\n", trace_name);
+ printf("\n");
+}
+
+
+/* signal handling */
+
+static void handler(int signo)
+{
+ printf("Signal %d received : exiting cleanly\n", signo);
+ quit_program = 1;
+}
+
+
+
+int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name,
+ struct channel_trace_fd *fd_pairs)
+{
+ DIR *channel_dir = opendir(subchannel_name);
+ struct dirent *entry;
+ struct stat stat_buf;
+ int ret;
+ char path_channel[PATH_MAX];
+ int path_channel_len;
+ char *path_channel_ptr;
+ char path_trace[PATH_MAX];
+ int path_trace_len;
+ char *path_trace_ptr;
+ int open_ret = 0;
+
+ if(channel_dir == NULL) {
+ perror(subchannel_name);
+ open_ret = ENOENT;
+ goto end;
+ }
+
+ printf("Creating trace subdirectory %s\n", subtrace_name);
+ ret = mkdir(subtrace_name, S_IRWXU|S_IRWXG|S_IRWXO);
+ if(ret == -1) {
+ if(errno != EEXIST) {
+ perror(subtrace_name);
+ open_ret = -1;
+ goto end;
+ }
+ }
+
+ strncpy(path_channel, subchannel_name, PATH_MAX-1);
+ path_channel_len = strlen(path_channel);
+ path_channel[path_channel_len] = '/';
+ path_channel_len++;
+ path_channel_ptr = path_channel + path_channel_len;
+
+ strncpy(path_trace, subtrace_name, PATH_MAX-1);
+ path_trace_len = strlen(path_trace);
+ path_trace[path_trace_len] = '/';
+ path_trace_len++;
+ path_trace_ptr = path_trace + path_trace_len;
+
+ while((entry = readdir(channel_dir)) != NULL) {
+
+ if(entry->d_name[0] == '.') continue;
+
+ strncpy(path_channel_ptr, entry->d_name, PATH_MAX - path_channel_len);
+ strncpy(path_trace_ptr, entry->d_name, PATH_MAX - path_trace_len);
+
+ ret = stat(path_channel, &stat_buf);
+ if(ret == -1) {
+ perror(path_channel);
+ continue;
+ }
+
+ printf("Channel file : %s\n", path_channel);
+
+ if(S_ISDIR(stat_buf.st_mode)) {
+
+ printf("Entering channel subdirectory...\n");
+ ret = open_channel_trace_pairs(path_channel, path_trace, fd_pairs);
+ if(ret < 0) continue;
+ } else if(S_ISREG(stat_buf.st_mode)) {
+ printf("Opening file.\n");
+
+ fd_pairs->pair = realloc(fd_pairs->pair,
+ ++fd_pairs->num_pairs * sizeof(struct fd_pair));
+
+ /* Open the channel in read mode */
+ fd_pairs->pair[fd_pairs->num_pairs-1].channel =
+ open(path_channel, O_RDONLY | O_NONBLOCK);
+ if(fd_pairs->pair[fd_pairs->num_pairs-1].channel == -1) {
+ perror(path_channel);
+ fd_pairs->num_pairs--;
+ continue;
+ }
+ /* Open the trace in write mode, only append if append_mode */
+ ret = stat(path_trace, &stat_buf);
+ if(ret == 0) {
+ if(append_mode) {
+ printf("Appending to file %s as requested\n", path_trace);
+
+ fd_pairs->pair[fd_pairs->num_pairs-1].trace =
+ open(path_trace, O_WRONLY|O_APPEND,
+ S_IRWXU|S_IRWXG|S_IRWXO);
+
+ if(fd_pairs->pair[fd_pairs->num_pairs-1].trace == -1) {
+ perror(path_trace);
+ }
+ } else {
+ printf("File %s exists, cannot open. Try append mode.\n", path_trace);
+ open_ret = -1;
+ goto end;
+ }
+ } else {
+ if(errno == ENOENT) {
+ fd_pairs->pair[fd_pairs->num_pairs-1].trace =
+ open(path_trace, O_WRONLY|O_CREAT|O_EXCL,
+ S_IRWXU|S_IRWXG|S_IRWXO);
+ if(fd_pairs->pair[fd_pairs->num_pairs-1].trace == -1) {
+ perror(path_trace);
+ }
+ }
+ }
+ }
+ }
+
+end:
+ closedir(channel_dir);
+
+ return open_ret;
+}
+
+
+int read_subbuffer(struct fd_pair *pair)
+{
+ unsigned int subbuf_index;
+ int err, ret;
+
+
+ err = ioctl(pair->channel, RELAYFS_GET_SUBBUF,
+ &subbuf_index);
+ printf("index : %u\n", subbuf_index);
+ if(err != 0) {
+ perror("Error in reserving sub buffer");
+ ret = -EPERM;
+ goto get_error;
+ }
+
+ err = TEMP_FAILURE_RETRY(write(pair->trace,
+ pair->mmap + (subbuf_index * pair->subbuf_size),
+ pair->subbuf_size));
+
+ if(err < 0) {
+ perror("Error in writing to file");
+ ret = err;
+ goto write_error;
+ }
+
+
+write_error:
+ err = ioctl(pair->channel, RELAYFS_PUT_SUBBUF);
+ if(err != 0) {
+ perror("Error in unreserving sub buffer");
+ ret = -EPERM;
+ goto get_error;
+ }
+
+get_error:
+ return ret;
+}
+
+
+/* read_channels
+ *
+ * Read the realyfs channels and write them in the paired tracefiles.
+ *
+ * @fd_pairs : paired channels and trace files.
+ *
+ * returns 0 on success, -1 on error.
+ *
+ * Note that the high priority polled channels are consumed first. We then poll
+ * again to see if these channels are still in priority. Only when no
+ * high priority channel is left, we start reading low priority channels.
+ *
+ * Note that a channel is considered high priority when the buffer is almost
+ * full.
+ */
+
+int read_channels(struct channel_trace_fd *fd_pairs)
+{
+ struct pollfd *pollfd;
+ int i,j;
+ int num_rdy, num_hup;
+ int high_prio;
+ int ret;
+
+ if(fd_pairs->num_pairs <= 0) {
+ printf("No channel to read\n");
+ goto end;
+ }
+
+ /* Get the subbuf sizes and number */
+
+ for(i=0;i<fd_pairs->num_pairs;i++) {
+ struct fd_pair *pair = &fd_pairs->pair[i];
+
+ ret = ioctl(pair->channel, RELAYFS_GET_N_SUBBUFS,
+ &pair->n_subbufs);
+ if(ret != 0) {
+ perror("Error in getting the number of subbuffers");
+ goto end;
+ }
+ ret = ioctl(pair->channel, RELAYFS_GET_SUBBUF_SIZE,
+ &pair->subbuf_size);
+ if(ret != 0) {
+ perror("Error in getting the size of the subbuffers");
+ goto end;
+ }
+ }
+
+ /* Mmap each FD */
+ for(i=0;i<fd_pairs->num_pairs;i++) {
+ struct fd_pair *pair = &fd_pairs->pair[i];
+
+ pair->mmap = mmap(0, pair->subbuf_size * pair->n_subbufs, PROT_READ,
+ MAP_SHARED, pair->channel, 0);
+ if(pair->mmap == MAP_FAILED) {
+ perror("Mmap error");
+ goto munmap;
+ }
+ }
+
+
+ /* Start polling the FD */
+
+ pollfd = malloc(fd_pairs->num_pairs * sizeof(struct pollfd));
+
+ /* Note : index in pollfd is the same index as fd_pair->pair */
+ for(i=0;i<fd_pairs->num_pairs;i++) {
+ pollfd[i].fd = fd_pairs->pair[i].channel;
+ pollfd[i].events = POLLIN|POLLPRI;
+ }
+
+ while(1) {
+ high_prio = 0;
+ num_hup = 0;
+#ifdef DEBUG
+ printf("Press a key for next poll...\n");
+ char buf[1];
+ read(STDIN_FILENO, &buf, 1);
+ printf("Next poll (polling %d fd) :\n", fd_pairs->num_pairs);
+#endif //DEBUG
+
+ /* Have we received a signal ? */
+ if(quit_program) break;
+
+ num_rdy = poll(pollfd, fd_pairs->num_pairs, -1);
+ if(num_rdy == -1) {
+ perror("Poll error");
+ goto free_fd;
+ }
+
+ printf("Data received\n");
+
+ for(i=0;i<fd_pairs->num_pairs;i++) {
+ switch(pollfd[i].revents) {
+ case POLLERR:
+ printf("Error returned in polling fd %d.\n", pollfd[i].fd);
+ num_hup++;
+ break;
+ case POLLHUP:
+ printf("Polling fd %d tells it has hung up.\n", pollfd[i].fd);
+ num_hup++;
+ break;
+ case POLLNVAL:
+ printf("Polling fd %d tells fd is not open.\n", pollfd[i].fd);
+ num_hup++;
+ break;
+ case POLLPRI:
+ printf("Urgent read on fd %d\n", pollfd[i].fd);
+ /* Take care of high priority channels first. */
+ high_prio = 1;
+ ret |= read_subbuffer(&fd_pairs->pair[i]);
+ break;
+ }
+ }
+ /* If every FD has hung up, we end the read loop here */
+ if(num_hup == fd_pairs->num_pairs) break;
+
+ if(!high_prio) {
+ for(i=0;i<fd_pairs->num_pairs;i++) {
+ switch(pollfd[i].revents) {
+ case POLLIN:
+ /* Take care of low priority channels. */
+ printf("Normal read on fd %d\n", pollfd[i].fd);
+ ret |= read_subbuffer(&fd_pairs->pair[i]);
+ break;
+ }
+ }
+ }
+
+ }
+
+free_fd:
+ free(pollfd);
+
+ /* munmap only the successfully mmapped indexes */
+ i = fd_pairs->num_pairs;
+munmap:
+ /* Munmap each FD */
+ for(j=0;j<i;j++) {
+ struct fd_pair *pair = &fd_pairs->pair[j];
+ int err_ret;
+
+ err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs);
+ if(err_ret != 0) {
+ perror("Error in munmap");
+ }
+ ret |= err_ret;
+ }
+
+end:
+ return ret;
+}
+
+
+void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs)
+{
+ int i;
+ int ret;
+
+ for(i=0;i<fd_pairs->num_pairs;i++) {
+ ret = close(fd_pairs->pair[i].channel);
+ if(ret == -1) perror("Close error on channel");
+ ret = close(fd_pairs->pair[i].trace);
+ if(ret == -1) perror("Close error on trace");
+ }
+ free(fd_pairs->pair);
+}
+
+int main(int argc, char ** argv)
+{
+ int ret;
+ struct channel_trace_fd fd_pairs = { NULL, 0 };
+ struct sigaction act;
+
+ ret = parse_arguments(argc, argv);
+
+ if(ret != 0) show_arguments();
+ if(ret < 0) return EINVAL;
+ if(ret > 0) return 0;
+
+ show_info();
+
+ if(daemon_mode) {
+ ret = daemon(0, 0);
+
+ if(ret == -1) {
+ perror("An error occured while daemonizing.");
+ exit(-1);
+ }
+ }
+
+ /* Connect the signal handlers */
+ act.sa_handler = handler;
+ act.sa_flags = 0;
+ sigemptyset(&(act.sa_mask));
+ sigaddset(&(act.sa_mask), SIGTERM);
+ sigaddset(&(act.sa_mask), SIGQUIT);
+ sigaddset(&(act.sa_mask), SIGINT);
+ sigaction(SIGTERM, &act, NULL);
+ sigaction(SIGQUIT, &act, NULL);
+ sigaction(SIGINT, &act, NULL);
+
+ //return 0;
+ if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs))
+ goto close_channel;
+
+ ret = read_channels(&fd_pairs);
+
+close_channel:
+ close_channel_trace_pairs(&fd_pairs);
+
+ return ret;
+}
projects / ltt-control.git / commitdiff
