[lttng-ust.git] / ustd / ustd.c

/* Copyright (C) 2009  Pierre-Marc Fournier
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 */

#define _GNU_SOURCE

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/shm.h>
#include <fcntl.h>
#include <unistd.h>
#include <pthread.h>
#include <signal.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <getopt.h>

#include "ustd.h"
#include "usterr.h"
#include "ustcomm.h"

/* return value: 0 = subbuffer is finished, it won't produce data anymore
 *               1 = got subbuffer successfully
 *               <0 = error
 */

#define GET_SUBBUF_OK 1
#define GET_SUBBUF_DONE 0
#define GET_SUBBUF_DIED 2

#define PUT_SUBBUF_OK 1
#define PUT_SUBBUF_DIED 0
#define PUT_SUBBUF_PUSHED 2

char *sock_path=NULL;
char *trace_path=NULL;
int daemon_mode = 0;
char *pidfile = NULL;

/* Number of active buffers and the mutex to protect it. */
int active_buffers = 0;
pthread_mutex_t active_buffers_mutex = PTHREAD_MUTEX_INITIALIZER;
/* Whether a request to end the program was received. */
sig_atomic_t terminate_req = 0;

int get_subbuffer(struct buffer_info *buf)
{
	char *send_msg=NULL;
	char *received_msg=NULL;
	char *rep_code=NULL;
	int retval;
	int result;

	asprintf(&send_msg, "get_subbuffer %s", buf->name);
	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	if((result == -1 && errno == EPIPE) || result == 0) {
		DBG("app died while being traced");
		retval = GET_SUBBUF_DIED;
		goto end;
	}
	else if(result < 0) {
		ERR("get_subbuffer: ustcomm_send_request failed");
		retval = -1;
		goto end;
	}

	result = sscanf(received_msg, "%as %ld", &rep_code, &buf->consumed_old);
	if(result != 2 && result != 1) {
		ERR("unable to parse response to get_subbuffer");
		retval = -1;
		goto end_rep;
	}

	DBG("received msg is %s", received_msg);

	if(!strcmp(rep_code, "OK")) {
		DBG("got subbuffer %s", buf->name);
		retval = GET_SUBBUF_OK;
	}
	else if(nth_token_is(received_msg, "END", 0) == 1) {
		retval = GET_SUBBUF_DONE;
		goto end_rep;
	}
	else {
		DBG("error getting subbuffer %s", buf->name);
		retval = -1;
	}

	/* FIMXE: free correctly the stuff */
end_rep:
	if(rep_code)
		free(rep_code);
end:
	if(send_msg)
		free(send_msg);
	if(received_msg)
		free(received_msg);

	return retval;
}

int put_subbuffer(struct buffer_info *buf)
{
	char *send_msg=NULL;
	char *received_msg=NULL;
	char *rep_code=NULL;
	int retval;
	int result;

	asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	if(result < 0 && errno == ECONNRESET) {
		retval = PUT_SUBBUF_DIED;
		goto end;
	}
	if(result < 0) {
		ERR("put_subbuffer: send_message failed");
		retval = -1;
		goto end;
	}

	result = sscanf(received_msg, "%as", &rep_code);
	if(result != 1) {
		ERR("unable to parse response to put_subbuffer");
		retval = -1;
		goto end_rep;
	}

	if(!strcmp(rep_code, "OK")) {
		DBG("subbuffer put %s", buf->name);
		retval = PUT_SUBBUF_OK;
	}
	else {
		DBG("put_subbuffer: received error, we were pushed");
		retval = PUT_SUBBUF_PUSHED;
		goto end_rep;
	}

end_rep:
	if(rep_code)
		free(rep_code);

end:
	if(send_msg)
		free(send_msg);
	if(received_msg)
		free(received_msg);

	return retval;
}

void decrement_active_buffers(void *arg)
{
	pthread_mutex_lock(&active_buffers_mutex);
	active_buffers--;
	pthread_mutex_unlock(&active_buffers_mutex);
}

int create_dir_if_needed(char *dir)
{
	int result;
	result = mkdir(dir, 0777);
	if(result == -1) {
		if(errno != EEXIST) {
			PERROR("mkdir");
			return -1;
		}
	}

	return 0;
}

int is_directory(const char *dir)
{
	int result;
	struct stat st;

	result = stat(dir, &st);
	if(result == -1) {
		PERROR("stat");
		return 0;
	}

	if(!S_ISDIR(st.st_mode)) {
		return 0;
	}

	return 1;
}

struct buffer_info *connect_buffer(pid_t pid, const char *bufname)
{
	struct buffer_info *buf;
	char *send_msg;
	char *received_msg;
	int result;
	char *tmp;
	int fd;
	struct shmid_ds shmds;

	buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
	if(buf == NULL) {
		ERR("add_buffer: insufficient memory");
		return NULL;
	}

	buf->name = bufname;
	buf->pid = pid;

	/* connect to app */
	result = ustcomm_connect_app(buf->pid, &buf->conn);
	if(result) {
		WARN("unable to connect to process, it probably died before we were able to connect");
		return NULL;
	}

	/* get pidunique */
	asprintf(&send_msg, "get_pidunique");
	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	free(send_msg);
	if(result == -1) {
		ERR("problem in ustcomm_send_request(get_pidunique)");
		return NULL;
	}

	result = sscanf(received_msg, "%lld", &buf->pidunique);
	if(result != 1) {
		ERR("unable to parse response to get_pidunique");
		return NULL;
	}
	free(received_msg);
	DBG("got pidunique %lld", buf->pidunique);

	/* get shmid */
	asprintf(&send_msg, "get_shmid %s", buf->name);
	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	free(send_msg);
	if(result == -1) {
		ERR("problem in ustcomm_send_request(get_shmid)");
		return NULL;
	}

	result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
	if(result != 2) {
		ERR("unable to parse response to get_shmid (\"%s\")", received_msg);
		return NULL;
	}
	free(received_msg);
	DBG("got shmids %d %d", buf->shmid, buf->bufstruct_shmid);

	/* get n_subbufs */
	asprintf(&send_msg, "get_n_subbufs %s", buf->name);
	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	free(send_msg);
	if(result == -1) {
		ERR("problem in ustcomm_send_request(g_n_subbufs)");
		return NULL;
	}

	result = sscanf(received_msg, "%d", &buf->n_subbufs);
	if(result != 1) {
		ERR("unable to parse response to get_n_subbufs");
		return NULL;
	}
	free(received_msg);
	DBG("got n_subbufs %d", buf->n_subbufs);

	/* get subbuf size */
	asprintf(&send_msg, "get_subbuf_size %s", buf->name);
	ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	free(send_msg);

	result = sscanf(received_msg, "%d", &buf->subbuf_size);
	if(result != 1) {
		ERR("unable to parse response to get_subbuf_size");
		return NULL;
	}
	free(received_msg);
	DBG("got subbuf_size %d", buf->subbuf_size);

	/* attach memory */
	buf->mem = shmat(buf->shmid, NULL, 0);
	if(buf->mem == (void *) 0) {
		PERROR("shmat");
		return NULL;
	}
	DBG("successfully attached buffer memory");

	buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
	if(buf->bufstruct_mem == (void *) 0) {
		PERROR("shmat");
		return NULL;
	}
	DBG("successfully attached buffer bufstruct memory");

	/* obtain info on the memory segment */
	result = shmctl(buf->shmid, IPC_STAT, &shmds);
	if(result == -1) {
		PERROR("shmctl");
		return NULL;
	}
	buf->memlen = shmds.shm_segsz;

	/* open file for output */
	if(!trace_path) {
		/* Only create the directory if using the default path, because
		 * of the risk of typo when using trace path override. We don't
		 * want to risk creating plenty of useless directories in that case.
		 */
		result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
		if(result == -1) {
			ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
			return NULL;
		}

		trace_path = USTD_DEFAULT_TRACE_PATH;
	}

	asprintf(&tmp, "%s/%u_%lld", trace_path, buf->pid, buf->pidunique);
	result = create_dir_if_needed(tmp);
	if(result == -1) {
		ERR("could not create directory %s", tmp);
		free(tmp);
		return NULL;
	}
	free(tmp);

	asprintf(&tmp, "%s/%u_%lld/%s", trace_path, buf->pid, buf->pidunique, buf->name);
	result = fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 00600);
	if(result == -1) {
		PERROR("open");
		ERR("failed opening trace file %s", tmp);
		return NULL;
	}
	buf->file_fd = fd;
	free(tmp);

	pthread_mutex_lock(&active_buffers_mutex);
	active_buffers++;
	pthread_mutex_unlock(&active_buffers_mutex);

	return buf;
}

int consumer_loop(struct buffer_info *buf)
{
	int result;

	pthread_cleanup_push(decrement_active_buffers, NULL);

	for(;;) {
		/* get the subbuffer */
		result = get_subbuffer(buf);
		if(result == -1) {
			ERR("error getting subbuffer");
			continue;
		}
		else if(result == GET_SUBBUF_DONE) {
			/* this is done */
			break;
		}
		else if(result == GET_SUBBUF_DIED) {
			finish_consuming_dead_subbuffer(buf);
			break;
		}

		/* write data to file */
		result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
		if(result == -1) {
			PERROR("write");
			/* FIXME: maybe drop this trace */
		}

		/* put the subbuffer */
		/* FIXME: we actually should unput the buffer before consuming... */
		result = put_subbuffer(buf);
		if(result == -1) {
			ERR("unknown error putting subbuffer (channel=%s)", buf->name);
			break;
		}
		else if(result == PUT_SUBBUF_PUSHED) {
			ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
			break;
		}
		else if(result == PUT_SUBBUF_DIED) {
			WARN("application died while putting subbuffer");
			/* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
			finish_consuming_dead_subbuffer(buf);
			break;
		}
		else if(result == PUT_SUBBUF_OK) {
		}
	}

	DBG("thread for buffer %s is stopping", buf->name);

	/* FIXME: destroy, unalloc... */

	pthread_cleanup_pop(1);

	return 0;
}

void free_buffer(struct buffer_info *buf)
{
}

struct consumer_thread_args {
	pid_t pid;
	const char *bufname;
};

void *consumer_thread(void *arg)
{
	struct buffer_info *buf = (struct buffer_info *) arg;
	struct consumer_thread_args *args = (struct consumer_thread_args *) arg;

	DBG("GOT ARGS: pid %d bufname %s", args->pid, args->bufname);

	buf = connect_buffer(args->pid, args->bufname);
	if(buf == NULL) {
		ERR("failed to connect to buffer");
		goto end;
	}

	consumer_loop(buf);

	free_buffer(buf);

	end:
	/* bufname is free'd in free_buffer() */
	free(args);
	return NULL;
}

int start_consuming_buffer(pid_t pid, const char *bufname)
{
	pthread_t thr;
	struct consumer_thread_args *args;

	DBG("beginning of start_consuming_buffer: args: pid %d bufname %s", pid, bufname);

	args = (struct consumer_thread_args *) malloc(sizeof(struct consumer_thread_args));

	args->pid = pid;
	args->bufname = strdup(bufname);
	DBG("beginning2 of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);

	pthread_create(&thr, NULL, consumer_thread, args);
	DBG("end of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);

	return 0;
}

void usage(void)
{
	fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
			"\t-h\t\tDisplay this usage.\n"
			"\t-o DIR\t\tSpecify the directory where to output the traces.\n"
			"\t-s PATH\t\tSpecify the path to use for the daemon socket.\n"
			"\t-d\t\tStart as a daemon.\n"
			"\t--pidfile FILE\tWrite the PID in this file (when using -d).\n");
}

int parse_args(int argc, char **argv)
{
	int c;

	while (1) {
		int option_index = 0;
		static struct option long_options[] = {
			{"pidfile", 1, 0, 'p'},
			{"help", 0, 0, 'h'},
			{"version", 0, 0, 'V'},
			{0, 0, 0, 0}
		};

		c = getopt_long(argc, argv, "hs:o:d", long_options, &option_index);
		if (c == -1)
			break;

		switch (c) {
		case 0:
			printf("option %s", long_options[option_index].name);
			if (optarg)
				printf(" with arg %s", optarg);
			printf("\n");
			break;
		case 's':
			sock_path = optarg;
			break;
		case 'o':
			trace_path = optarg;
			if(!is_directory(trace_path)) {
				ERR("Not a valid directory. (%s)", trace_path);
				return -1;
			}
			break;
		case 'd':
			daemon_mode = 1;
			break;
		case 'p':
			pidfile = strdup(optarg);
			break;
		case 'h':
			usage();
			exit(0);
		case 'V':
			printf("Version 0.0\n");
			break;

		default:
			/* unknown option or other error; error is
			printed by getopt, just return */
			return -1;
		}
	}

	return 0;
}

void sigterm_handler(int sig)
{
	terminate_req = 1;
}

static int write_pidfile(const char *file_name, pid_t pid)
{
	FILE *pidfp;

	pidfp = fopen(file_name, "w");
	if(!pidfp) {
		PERROR("fopen (%s)", pidfile);
		WARN("killing child process");
		return -1;
	}

	fprintf(pidfp, "%d\n", pid);

	fclose(pidfp);

	return 0;
}

int start_ustd(int fd)
{
	struct ustcomm_ustd ustd;
	int result;
	sigset_t sigset;
	struct sigaction sa;

	result = sigemptyset(&sigset);
	if(result == -1) {
		PERROR("sigemptyset");
		return 1;
	}
	sa.sa_handler = sigterm_handler;
	sa.sa_mask = sigset;
	sa.sa_flags = SA_RESTART;
	result = sigaction(SIGTERM, &sa, NULL);
	if(result == -1) {
		PERROR("sigaction");
		return 1;
	}

	result = ustcomm_init_ustd(&ustd, sock_path);
	if(result == -1) {
		ERR("failed to initialize socket");
		return 1;
	}

	/* setup handler for SIGPIPE */
	result = sigemptyset(&sigset);
	if(result == -1) {
		PERROR("sigemptyset");
		return 1;
	}
	result = sigaddset(&sigset, SIGPIPE);
	if(result == -1) {
		PERROR("sigaddset");
		return 1;
	}
	result = sigprocmask(SIG_BLOCK, &sigset, NULL);
	if(result == -1) {
		PERROR("sigprocmask");
		return 1;
	}

	/* Write pidfile */
	if(pidfile) {
		result = write_pidfile(pidfile, getpid());
		if(result == -1) {
			ERR("failed to write pidfile");
			return 1;
		}
	}

	/* Notify parent that we are successfully started. */
	if(fd != -1) {
		/* write any one character */
		result = write(fd, "!", 1);
		if(result == -1) {
			PERROR("write");
			return -1;
		}
		if(result != 1) {
			ERR("Problem sending confirmation of daemon start to parent");
			return -1;
		}
		result = close(fd);
		if(result == -1) {
			PERROR("close");
		}
	}

	/* app loop */
	for(;;) {
		char *recvbuf;

		/* check for requests on our public socket */
		result = ustcomm_ustd_recv_message(&ustd, &recvbuf, NULL, 100);
		if(result == -1) {
			ERR("error in ustcomm_ustd_recv_message");
			goto loop_end;
		}
		if(result > 0) {
			if(!strncmp(recvbuf, "collect", 7)) {
				pid_t pid;
				char *bufname;
				int result;

				result = sscanf(recvbuf, "%*s %d %50as", &pid, &bufname);
				if(result != 2) {
					ERR("parsing error: %s", recvbuf);
					goto free_bufname;
				}

				result = start_consuming_buffer(pid, bufname);
				if(result < 0) {
					ERR("error in add_buffer");
					goto free_bufname;
				}

				free_bufname:
				free(bufname);
			}

			free(recvbuf);
		}

		loop_end:

		if(terminate_req) {
			pthread_mutex_lock(&active_buffers_mutex);
			if(active_buffers == 0) {
				pthread_mutex_unlock(&active_buffers_mutex);
				break;
			}
			pthread_mutex_unlock(&active_buffers_mutex);
		}
	}

	return 0;
}

int start_ustd_daemon()
{
	int result;
	int fd[2];
	pid_t child_pid;

	result = pipe(fd);

	result = child_pid = fork();
	if(result == -1) {
		PERROR("fork");
		return -1;
	}
	else if(result == 0) {
		return start_ustd(fd[1]);
	}
	else {
		char buf;

		result = read(fd[0], &buf, 1);
		if(result == -1) {
			PERROR("read");
			return -1;
		}
		if(result != 1) {
			ERR("did not receive valid confirmation that the daemon is started");
			return -1;
		}

		result = close(fd[0]);
		if(result == -1) {
			PERROR("close");
		}

		DBG("The daemon is now successfully started");
	}

	/* Wait for confirmation that the server is ready. */


	return 0;
}

int main(int argc, char **argv)
{
	int result;

	result = parse_args(argc, argv);
	if(result == -1) {
		exit(1);
	}

	if(daemon_mode) {
		result = start_ustd_daemon();
	}
	else {
		result = start_ustd(-1);
	}

	return result;
}
Commit	Line	Data
c39c72ee	1	/* Copyright (C) 2009 Pierre-Marc Fournier
1f8b0dff	2	*
c39c72ee PMF	3	* This library is free software; you can redistribute it and/or
	4	* modify it under the terms of the GNU Lesser General Public
	5	* License as published by the Free Software Foundation; either
	6	* version 2.1 of the License, or (at your option) any later version.
1f8b0dff	7	*
c39c72ee	8	* This library is distributed in the hope that it will be useful,
1f8b0dff	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
c39c72ee PMF	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
c39c72ee PMF	11	* Lesser General Public License for more details.
1f8b0dff	12	*
c39c72ee PMF	13	* You should have received a copy of the GNU Lesser General Public
	14	* License along with this library; if not, write to the Free Software
	15	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
1f8b0dff PMF	16	*/
1f8b0dff PMF	17
3796af9b PMF	18	#define _GNU_SOURCE
	19
	20	#include <sys/types.h>
cd226f25	21	#include <sys/stat.h>
3796af9b	22	#include <sys/shm.h>
688760ef PMF	23	#include <fcntl.h>
688760ef PMF	24	#include <unistd.h>
3a7b90de	25	#include <pthread.h>
a3cdd4a7	26	#include <signal.h>
3796af9b PMF	27
	28	#include <stdlib.h>
	29	#include <stdio.h>
	30	#include <string.h>
a3cdd4a7 PMF	31	#include <errno.h>
a3cdd4a7 PMF	32	#include <assert.h>
cd226f25	33	#include <getopt.h>
3796af9b	34
0b0cd937	35	#include "ustd.h"
6af64c43	36	#include "usterr.h"
3796af9b PMF	37	#include "ustcomm.h"
3796af9b PMF	38
3a7b90de PMF	39	/* return value: 0 = subbuffer is finished, it won't produce data anymore
	40	* 1 = got subbuffer successfully
	41	* <0 = error
	42	*/
3796af9b	43
8cefc145 PMF	44	#define GET_SUBBUF_OK 1
	45	#define GET_SUBBUF_DONE 0
	46	#define GET_SUBBUF_DIED 2
	47
a3cdd4a7 PMF	48	#define PUT_SUBBUF_OK 1
	49	#define PUT_SUBBUF_DIED 0
	50	#define PUT_SUBBUF_PUSHED 2
	51
c97d4437	52	char *sock_path=NULL;
cd226f25	53	char *trace_path=NULL;
bce2937a	54	int daemon_mode = 0;
2730a7d6	55	char *pidfile = NULL;
cd226f25	56
3158b808 PMF	57	/* Number of active buffers and the mutex to protect it. */
	58	int active_buffers = 0;
	59	pthread_mutex_t active_buffers_mutex = PTHREAD_MUTEX_INITIALIZER;
	60	/* Whether a request to end the program was received. */
	61	sig_atomic_t terminate_req = 0;
	62
688760ef PMF	63	int get_subbuffer(struct buffer_info *buf)
688760ef PMF	64	{
ab805ccd PMF	65	char *send_msg=NULL;
	66	char *received_msg=NULL;
	67	char *rep_code=NULL;
688760ef PMF	68	int retval;
	69	int result;
	70
	71	asprintf(&send_msg, "get_subbuffer %s", buf->name);
3bb56863	72	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
dc2f5ffa	73	if((result == -1 && errno == EPIPE) \|\| result == 0) {
409e2abe PMF	74	DBG("app died while being traced");
409e2abe PMF	75	retval = GET_SUBBUF_DIED;
ab805ccd	76	goto end;
a3cdd4a7 PMF	77	}
a3cdd4a7 PMF	78	else if(result < 0) {
3bb56863	79	ERR("get_subbuffer: ustcomm_send_request failed");
ab805ccd PMF	80	retval = -1;
ab805ccd PMF	81	goto end;
688760ef	82	}
688760ef PMF	83
688760ef PMF	84	result = sscanf(received_msg, "%as %ld", &rep_code, &buf->consumed_old);
3a7b90de	85	if(result != 2 && result != 1) {
688760ef	86	ERR("unable to parse response to get_subbuffer");
ab805ccd PMF	87	retval = -1;
ab805ccd PMF	88	goto end_rep;
688760ef	89	}
3a7b90de PMF	90
3a7b90de PMF	91	DBG("received msg is %s", received_msg);
688760ef PMF	92
	93	if(!strcmp(rep_code, "OK")) {
	94	DBG("got subbuffer %s", buf->name);
8cefc145	95	retval = GET_SUBBUF_OK;
688760ef	96	}
3a7b90de	97	else if(nth_token_is(received_msg, "END", 0) == 1) {
ab805ccd PMF	98	retval = GET_SUBBUF_DONE;
ab805ccd PMF	99	goto end_rep;
3a7b90de	100	}
688760ef	101	else {
3a7b90de PMF	102	DBG("error getting subbuffer %s", buf->name);
3a7b90de PMF	103	retval = -1;
688760ef PMF	104	}
688760ef PMF	105
3a7b90de	106	/* FIMXE: free correctly the stuff */
ab805ccd PMF	107	end_rep:
	108	if(rep_code)
	109	free(rep_code);
	110	end:
	111	if(send_msg)
	112	free(send_msg);
	113	if(received_msg)
	114	free(received_msg);
	115
688760ef PMF	116	return retval;
	117	}
	118
	119	int put_subbuffer(struct buffer_info *buf)
	120	{
ab805ccd PMF	121	char *send_msg=NULL;
	122	char *received_msg=NULL;
	123	char *rep_code=NULL;
688760ef PMF	124	int retval;
	125	int result;
	126
	127	asprintf(&send_msg, "put_subbuffer %s %ld", buf->name, buf->consumed_old);
3bb56863	128	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
ab805ccd PMF	129	if(result < 0 && errno == ECONNRESET) {
	130	retval = PUT_SUBBUF_DIED;
	131	goto end;
	132	}
688760ef PMF	133	if(result < 0) {
688760ef PMF	134	ERR("put_subbuffer: send_message failed");
ab805ccd PMF	135	retval = -1;
ab805ccd PMF	136	goto end;
688760ef	137	}
688760ef PMF	138
	139	result = sscanf(received_msg, "%as", &rep_code);
	140	if(result != 1) {
	141	ERR("unable to parse response to put_subbuffer");
ab805ccd PMF	142	retval = -1;
ab805ccd PMF	143	goto end_rep;
688760ef	144	}
688760ef PMF	145
	146	if(!strcmp(rep_code, "OK")) {
	147	DBG("subbuffer put %s", buf->name);
a3cdd4a7	148	retval = PUT_SUBBUF_OK;
688760ef PMF	149	}
688760ef PMF	150	else {
a3cdd4a7	151	DBG("put_subbuffer: received error, we were pushed");
ab805ccd PMF	152	retval = PUT_SUBBUF_PUSHED;
ab805ccd PMF	153	goto end_rep;
688760ef PMF	154	}
688760ef PMF	155
ab805ccd PMF	156	end_rep:
	157	if(rep_code)
	158	free(rep_code);
	159
	160	end:
	161	if(send_msg)
	162	free(send_msg);
	163	if(received_msg)
	164	free(received_msg);
	165
688760ef PMF	166	return retval;
	167	}
	168
3158b808 PMF	169	void decrement_active_buffers(void *arg)
	170	{
	171	pthread_mutex_lock(&active_buffers_mutex);
	172	active_buffers--;
	173	pthread_mutex_unlock(&active_buffers_mutex);
	174	}
	175
72ebd39a PMF	176	int create_dir_if_needed(char *dir)
	177	{
	178	int result;
	179	result = mkdir(dir, 0777);
	180	if(result == -1) {
	181	if(errno != EEXIST) {
4d70f833	182	PERROR("mkdir");
72ebd39a PMF	183	return -1;
	184	}
	185	}
	186
	187	return 0;
	188	}
	189
cd226f25 PMF	190	int is_directory(const char *dir)
	191	{
	192	int result;
	193	struct stat st;
	194
	195	result = stat(dir, &st);
	196	if(result == -1) {
	197	PERROR("stat");
	198	return 0;
	199	}
	200
	201	if(!S_ISDIR(st.st_mode)) {
	202	return 0;
	203	}
	204
	205	return 1;
	206	}
	207
f99c0b5c	208	struct buffer_info connect_buffer(pid_t pid, const char bufname)
3a7b90de PMF	209	{
	210	struct buffer_info *buf;
	211	char *send_msg;
	212	char *received_msg;
	213	int result;
	214	char *tmp;
	215	int fd;
a3cdd4a7	216	struct shmid_ds shmds;
3a7b90de PMF	217
	218	buf = (struct buffer_info *) malloc(sizeof(struct buffer_info));
	219	if(buf == NULL) {
	220	ERR("add_buffer: insufficient memory");
f99c0b5c	221	return NULL;
3a7b90de PMF	222	}
	223
	224	buf->name = bufname;
	225	buf->pid = pid;
	226
4e2a8808 PMF	227	/* connect to app */
	228	result = ustcomm_connect_app(buf->pid, &buf->conn);
	229	if(result) {
a3cdd4a7	230	WARN("unable to connect to process, it probably died before we were able to connect");
f99c0b5c	231	return NULL;
4e2a8808 PMF	232	}
4e2a8808 PMF	233
ed1317e7 PMF	234	/* get pidunique */
	235	asprintf(&send_msg, "get_pidunique");
	236	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
	237	free(send_msg);
	238	if(result == -1) {
	239	ERR("problem in ustcomm_send_request(get_pidunique)");
f99c0b5c	240	return NULL;
ed1317e7 PMF	241	}
	242
	243	result = sscanf(received_msg, "%lld", &buf->pidunique);
	244	if(result != 1) {
	245	ERR("unable to parse response to get_pidunique");
f99c0b5c	246	return NULL;
ed1317e7 PMF	247	}
	248	free(received_msg);
	249	DBG("got pidunique %lld", buf->pidunique);
	250
3a7b90de PMF	251	/* get shmid */
3a7b90de PMF	252	asprintf(&send_msg, "get_shmid %s", buf->name);
a3cdd4a7	253	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
3a7b90de	254	free(send_msg);
a3cdd4a7 PMF	255	if(result == -1) {
a3cdd4a7 PMF	256	ERR("problem in ustcomm_send_request(get_shmid)");
f99c0b5c	257	return NULL;
a3cdd4a7	258	}
3a7b90de	259
8cefc145 PMF	260	result = sscanf(received_msg, "%d %d", &buf->shmid, &buf->bufstruct_shmid);
8cefc145 PMF	261	if(result != 2) {
204141ee	262	ERR("unable to parse response to get_shmid (\"%s\")", received_msg);
f99c0b5c	263	return NULL;
3a7b90de PMF	264	}
3a7b90de PMF	265	free(received_msg);
8cefc145	266	DBG("got shmids %d %d", buf->shmid, buf->bufstruct_shmid);
3a7b90de PMF	267
	268	/* get n_subbufs */
	269	asprintf(&send_msg, "get_n_subbufs %s", buf->name);
a3cdd4a7	270	result = ustcomm_send_request(&buf->conn, send_msg, &received_msg);
3a7b90de	271	free(send_msg);
a3cdd4a7 PMF	272	if(result == -1) {
a3cdd4a7 PMF	273	ERR("problem in ustcomm_send_request(g_n_subbufs)");
f99c0b5c	274	return NULL;
a3cdd4a7	275	}
3a7b90de PMF	276
	277	result = sscanf(received_msg, "%d", &buf->n_subbufs);
	278	if(result != 1) {
	279	ERR("unable to parse response to get_n_subbufs");
f99c0b5c	280	return NULL;
3a7b90de PMF	281	}
	282	free(received_msg);
	283	DBG("got n_subbufs %d", buf->n_subbufs);
	284
	285	/* get subbuf size */
	286	asprintf(&send_msg, "get_subbuf_size %s", buf->name);
4e2a8808	287	ustcomm_send_request(&buf->conn, send_msg, &received_msg);
3a7b90de PMF	288	free(send_msg);
	289
	290	result = sscanf(received_msg, "%d", &buf->subbuf_size);
	291	if(result != 1) {
	292	ERR("unable to parse response to get_subbuf_size");
f99c0b5c	293	return NULL;
3a7b90de PMF	294	}
	295	free(received_msg);
	296	DBG("got subbuf_size %d", buf->subbuf_size);
	297
	298	/* attach memory */
	299	buf->mem = shmat(buf->shmid, NULL, 0);
	300	if(buf->mem == (void *) 0) {
4d70f833	301	PERROR("shmat");
f99c0b5c	302	return NULL;
3a7b90de	303	}
8cefc145 PMF	304	DBG("successfully attached buffer memory");
	305
	306	buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
	307	if(buf->bufstruct_mem == (void *) 0) {
4d70f833	308	PERROR("shmat");
f99c0b5c	309	return NULL;
8cefc145 PMF	310	}
8cefc145 PMF	311	DBG("successfully attached buffer bufstruct memory");
3a7b90de	312
a3cdd4a7 PMF	313	/* obtain info on the memory segment */
	314	result = shmctl(buf->shmid, IPC_STAT, &shmds);
	315	if(result == -1) {
4d70f833	316	PERROR("shmctl");
f99c0b5c	317	return NULL;
a3cdd4a7 PMF	318	}
	319	buf->memlen = shmds.shm_segsz;
	320
3a7b90de	321	/* open file for output */
cd226f25 PMF	322	if(!trace_path) {
	323	/* Only create the directory if using the default path, because
	324	* of the risk of typo when using trace path override. We don't
	325	* want to risk creating plenty of useless directories in that case.
	326	*/
	327	result = create_dir_if_needed(USTD_DEFAULT_TRACE_PATH);
	328	if(result == -1) {
	329	ERR("could not create directory %s", USTD_DEFAULT_TRACE_PATH);
f99c0b5c	330	return NULL;
cd226f25 PMF	331	}
	332
	333	trace_path = USTD_DEFAULT_TRACE_PATH;
72ebd39a PMF	334	}
72ebd39a PMF	335
ed1317e7	336	asprintf(&tmp, "%s/%u_%lld", trace_path, buf->pid, buf->pidunique);
72ebd39a PMF	337	result = create_dir_if_needed(tmp);
	338	if(result == -1) {
	339	ERR("could not create directory %s", tmp);
	340	free(tmp);
f99c0b5c	341	return NULL;
72ebd39a PMF	342	}
	343	free(tmp);
	344
204141ee	345	asprintf(&tmp, "%s/%u_%lld/%s", trace_path, buf->pid, buf->pidunique, buf->name);
ed1317e7	346	result = fd = open(tmp, O_WRONLY \| O_CREAT \| O_TRUNC \| O_EXCL, 00600);
3a7b90de PMF	347	if(result == -1) {
3a7b90de PMF	348	PERROR("open");
6cb88bc0	349	ERR("failed opening trace file %s", tmp);
f99c0b5c	350	return NULL;
3a7b90de PMF	351	}
	352	buf->file_fd = fd;
	353	free(tmp);
	354
3158b808 PMF	355	pthread_mutex_lock(&active_buffers_mutex);
	356	active_buffers++;
	357	pthread_mutex_unlock(&active_buffers_mutex);
	358
f99c0b5c PMF	359	return buf;
	360	}
	361
	362	int consumer_loop(struct buffer_info *buf)
	363	{
	364	int result;
	365
	366	pthread_cleanup_push(decrement_active_buffers, NULL);
	367
	368	for(;;) {
	369	/* get the subbuffer */
	370	result = get_subbuffer(buf);
	371	if(result == -1) {
	372	ERR("error getting subbuffer");
	373	continue;
	374	}
	375	else if(result == GET_SUBBUF_DONE) {
	376	/* this is done */
	377	break;
	378	}
	379	else if(result == GET_SUBBUF_DIED) {
	380	finish_consuming_dead_subbuffer(buf);
	381	break;
	382	}
	383
	384	/* write data to file */
	385	result = patient_write(buf->file_fd, buf->mem + (buf->consumed_old & (buf->n_subbufs * buf->subbuf_size-1)), buf->subbuf_size);
	386	if(result == -1) {
	387	PERROR("write");
	388	/* FIXME: maybe drop this trace */
	389	}
	390
	391	/* put the subbuffer */
	392	/* FIXME: we actually should unput the buffer before consuming... */
	393	result = put_subbuffer(buf);
	394	if(result == -1) {
	395	ERR("unknown error putting subbuffer (channel=%s)", buf->name);
	396	break;
	397	}
	398	else if(result == PUT_SUBBUF_PUSHED) {
	399	ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
	400	break;
	401	}
	402	else if(result == PUT_SUBBUF_DIED) {
	403	WARN("application died while putting subbuffer");
	404	/* FIXME: probably need to skip the first subbuffer in finish_consuming_dead_subbuffer */
	405	finish_consuming_dead_subbuffer(buf);
	406	break;
	407	}
	408	else if(result == PUT_SUBBUF_OK) {
	409	}
	410	}
	411
	412	DBG("thread for buffer %s is stopping", buf->name);
	413
	414	/* FIXME: destroy, unalloc... */
	415
	416	pthread_cleanup_pop(1);
	417
	418	return 0;
	419	}
	420
	421	void free_buffer(struct buffer_info *buf)
	422	{
423	}
424
425	struct consumer_thread_args {
426	pid_t pid;
427	const char *bufname;
428	};
429
430	void consumer_thread(void arg)
431	{
432	struct buffer_info buf = (struct buffer_info ) arg;
433	struct consumer_thread_args args = (struct consumer_thread_args ) arg;
434
435	DBG("GOT ARGS: pid %d bufname %s", args->pid, args->bufname);
436
437	buf = connect_buffer(args->pid, args->bufname);
438	if(buf == NULL) {
439	ERR("failed to connect to buffer");
440	goto end;
441	}
442
443	consumer_loop(buf);
444
445	free_buffer(buf);
446
447	end:
448	/* bufname is free'd in free_buffer() */
449	free(args);
450	return NULL;
451	}
452
453	int start_consuming_buffer(pid_t pid, const char *bufname)
454	{
455	pthread_t thr;
456	struct consumer_thread_args *args;
457
458	DBG("beginning of start_consuming_buffer: args: pid %d bufname %s", pid, bufname);
459
460	args = (struct consumer_thread_args *) malloc(sizeof(struct consumer_thread_args));
461
462	args->pid = pid;
463	args->bufname = strdup(bufname);
464	DBG("beginning2 of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
465
466	pthread_create(&thr, NULL, consumer_thread, args);
467	DBG("end of start_consuming_buffer: args: pid %d bufname %s", args->pid, args->bufname);
3a7b90de PMF	468
	469	return 0;
	470	}
	471
cd226f25 PMF	472	void usage(void)
	473	{
	474	fprintf(stderr, "Usage:\nustd OPTIONS\n\nOptions:\n"
	475	"\t-h\t\tDisplay this usage.\n"
	476	"\t-o DIR\t\tSpecify the directory where to output the traces.\n"
bce2937a PMF	477	"\t-s PATH\t\tSpecify the path to use for the daemon socket.\n"
	478	"\t-d\t\tStart as a daemon.\n"
	479	"\t--pidfile FILE\tWrite the PID in this file (when using -d).\n");
cd226f25 PMF	480	}
	481
	482	int parse_args(int argc, char **argv)
	483	{
	484	int c;
	485
	486	while (1) {
	487	int option_index = 0;
	488	static struct option long_options[] = {
bce2937a	489	{"pidfile", 1, 0, 'p'},
cd226f25 PMF	490	{"help", 0, 0, 'h'},
	491	{"version", 0, 0, 'V'},
	492	{0, 0, 0, 0}
	493	};
	494
bce2937a	495	c = getopt_long(argc, argv, "hs:o:d", long_options, &option_index);
cd226f25 PMF	496	if (c == -1)
	497	break;
	498
	499	switch (c) {
	500	case 0:
	501	printf("option %s", long_options[option_index].name);
	502	if (optarg)
	503	printf(" with arg %s", optarg);
	504	printf("\n");
	505	break;
	506	case 's':
	507	sock_path = optarg;
	508	break;
	509	case 'o':
	510	trace_path = optarg;
	511	if(!is_directory(trace_path)) {
	512	ERR("Not a valid directory. (%s)", trace_path);
	513	return -1;
	514	}
	515	break;
bce2937a PMF	516	case 'd':
	517	daemon_mode = 1;
	518	break;
2730a7d6 PMF	519	case 'p':
	520	pidfile = strdup(optarg);
	521	break;
cd226f25 PMF	522	case 'h':
	523	usage();
	524	exit(0);
	525	case 'V':
	526	printf("Version 0.0\n");
	527	break;
	528
	529	default:
	530	/* unknown option or other error; error is
	531	printed by getopt, just return */
	532	return -1;
	533	}
	534	}
	535
	536	return 0;
	537	}
	538
3158b808 PMF	539	void sigterm_handler(int sig)
	540	{
	541	terminate_req = 1;
	542	}
	543
2b3c64a4 PMF	544	static int write_pidfile(const char *file_name, pid_t pid)
	545	{
	546	FILE *pidfp;
	547
5d72e651	548	pidfp = fopen(file_name, "w");
2b3c64a4 PMF	549	if(!pidfp) {
	550	PERROR("fopen (%s)", pidfile);
	551	WARN("killing child process");
	552	return -1;
	553	}
	554
	555	fprintf(pidfp, "%d\n", pid);
	556
	557	fclose(pidfp);
	558
	559	return 0;
	560	}
	561
bce2937a	562	int start_ustd(int fd)
3796af9b PMF	563	{
	564	struct ustcomm_ustd ustd;
	565	int result;
a3cdd4a7	566	sigset_t sigset;
3158b808 PMF	567	struct sigaction sa;
	568
	569	result = sigemptyset(&sigset);
	570	if(result == -1) {
4d70f833	571	PERROR("sigemptyset");
3158b808 PMF	572	return 1;
	573	}
	574	sa.sa_handler = sigterm_handler;
	575	sa.sa_mask = sigset;
	576	sa.sa_flags = SA_RESTART;
	577	result = sigaction(SIGTERM, &sa, NULL);
	578	if(result == -1) {
	579	PERROR("sigaction");
	580	return 1;
	581	}
3796af9b	582
cd226f25	583	result = ustcomm_init_ustd(&ustd, sock_path);
3796af9b PMF	584	if(result == -1) {
	585	ERR("failed to initialize socket");
	586	return 1;
	587	}
	588
3158b808	589	/* setup handler for SIGPIPE */
a3cdd4a7 PMF	590	result = sigemptyset(&sigset);
a3cdd4a7 PMF	591	if(result == -1) {
4d70f833	592	PERROR("sigemptyset");
a3cdd4a7 PMF	593	return 1;
	594	}
	595	result = sigaddset(&sigset, SIGPIPE);
	596	if(result == -1) {
4d70f833	597	PERROR("sigaddset");
a3cdd4a7 PMF	598	return 1;
	599	}
	600	result = sigprocmask(SIG_BLOCK, &sigset, NULL);
	601	if(result == -1) {
4d70f833	602	PERROR("sigprocmask");
a3cdd4a7 PMF	603	return 1;
	604	}
	605
2b3c64a4 PMF	606	/* Write pidfile */
	607	if(pidfile) {
	608	result = write_pidfile(pidfile, getpid());
	609	if(result == -1) {
	610	ERR("failed to write pidfile");
	611	return 1;
	612	}
	613	}
	614
bce2937a PMF	615	/* Notify parent that we are successfully started. */
	616	if(fd != -1) {
	617	/* write any one character */
	618	result = write(fd, "!", 1);
	619	if(result == -1) {
	620	PERROR("write");
	621	return -1;
	622	}
	623	if(result != 1) {
	624	ERR("Problem sending confirmation of daemon start to parent");
	625	return -1;
	626	}
	627	result = close(fd);
	628	if(result == -1) {
	629	PERROR("close");
	630	}
	631	}
	632
688760ef	633	/* app loop */
3796af9b PMF	634	for(;;) {
	635	char *recvbuf;
	636
3a7b90de	637	/* check for requests on our public socket */
688760ef PMF	638	result = ustcomm_ustd_recv_message(&ustd, &recvbuf, NULL, 100);
	639	if(result == -1) {
	640	ERR("error in ustcomm_ustd_recv_message");
f99c0b5c	641	goto loop_end;
688760ef PMF	642	}
	643	if(result > 0) {
	644	if(!strncmp(recvbuf, "collect", 7)) {
	645	pid_t pid;
	646	char *bufname;
	647	int result;
3796af9b	648
688760ef PMF	649	result = sscanf(recvbuf, "%*s %d %50as", &pid, &bufname);
688760ef PMF	650	if(result != 2) {
f99c0b5c PMF	651	ERR("parsing error: %s", recvbuf);
f99c0b5c PMF	652	goto free_bufname;
688760ef	653	}
3796af9b	654
f99c0b5c	655	result = start_consuming_buffer(pid, bufname);
688760ef PMF	656	if(result < 0) {
688760ef PMF	657	ERR("error in add_buffer");
f99c0b5c	658	goto free_bufname;
688760ef	659	}
f99c0b5c PMF	660
	661	free_bufname:
	662	free(bufname);
3796af9b PMF	663	}
3796af9b PMF	664
688760ef	665	free(recvbuf);
3796af9b	666	}
3158b808	667
f99c0b5c PMF	668	loop_end:
f99c0b5c PMF	669
3158b808 PMF	670	if(terminate_req) {
	671	pthread_mutex_lock(&active_buffers_mutex);
	672	if(active_buffers == 0) {
	673	pthread_mutex_unlock(&active_buffers_mutex);
	674	break;
	675	}
	676	pthread_mutex_unlock(&active_buffers_mutex);
	677	}
3796af9b PMF	678	}
	679
	680	return 0;
	681	}
bce2937a PMF	682
	683	int start_ustd_daemon()
	684	{
	685	int result;
	686	int fd[2];
2730a7d6	687	pid_t child_pid;
bce2937a PMF	688
	689	result = pipe(fd);
	690
2730a7d6	691	result = child_pid = fork();
bce2937a PMF	692	if(result == -1) {
	693	PERROR("fork");
	694	return -1;
	695	}
	696	else if(result == 0) {
	697	return start_ustd(fd[1]);
	698	}
	699	else {
	700	char buf;
2730a7d6	701
bce2937a PMF	702	result = read(fd[0], &buf, 1);
	703	if(result == -1) {
	704	PERROR("read");
	705	return -1;
	706	}
	707	if(result != 1) {
	708	ERR("did not receive valid confirmation that the daemon is started");
	709	return -1;
	710	}
	711
	712	result = close(fd[0]);
	713	if(result == -1) {
	714	PERROR("close");
	715	}
	716
	717	DBG("The daemon is now successfully started");
	718	}
	719
	720	/* Wait for confirmation that the server is ready. */
	721
	722
	723	return 0;
	724	}
	725
	726	int main(int argc, char **argv)
	727	{
	728	int result;
	729
	730	result = parse_args(argc, argv);
	731	if(result == -1) {
	732	exit(1);
	733	}
	734
	735	if(daemon_mode) {
	736	result = start_ustd_daemon();
	737	}
	738	else {
	739	result = start_ustd(-1);
	740	}
	741
	742	return result;
	743	}