[ltt-control.git] / ltt / branches / poly / lttd / lttd.c

/* 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 _REENTRANT
#define _GNU_SOURCE
#include <features.h>
#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>
#include <pthread.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        _IOW(0xF4, 0x01,__u32)
/* 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;
static unsigned long num_threads = 1;
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            Number of threads to start.\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;
					case 'n':
						if(argn+1 < argc) {
							num_threads = strtoul(argv[argn+1], NULL, 0);
							argn++;
						}
						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	consumed_old;
	int err, ret;


	err = ioctl(pair->channel, RELAYFS_GET_SUBBUF, 
								&consumed_old);
	printf("cookie : %u\n", consumed_old);
	if(err != 0) {
		perror("Error in reserving sub buffer");
		ret = -EPERM;
		goto get_error;
	}
	
	err = TEMP_FAILURE_RETRY(write(pair->trace,
				pair->mmap 
					+ (consumed_old & ((pair->n_subbufs * pair->subbuf_size)-1)),
				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, &consumed_old);
	if(err != 0) {
		if(errno == -EFAULT) {
			perror("Error in unreserving sub buffer");
			ret = -EFAULT;
		} else if(errno == -EIO) {
			perror("Reader has been pushed by the writer, last subbuffer corrupted.");
			/* FIXME : we may delete the last written buffer if we wish. */
			ret = -EIO;
		}
		goto get_error;
	}

get_error:
	return ret;
}


int map_channels(struct channel_trace_fd *fd_pairs)
{
	int i,j;
	int ret=0;

	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;
		}
	}


	/* Error handling */
	/* munmap only the successfully mmapped indexes */
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;


}


int unmap_channels(struct channel_trace_fd *fd_pairs)
{
	int j;
	int ret=0;

	/* Munmap each FD */
	for(j=0;j<fd_pairs->num_pairs;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;
	}

	return ret;
}


/* read_channels
 *
 * Read the relayfs 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;

	/* 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);

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 = 0;
	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);


	if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs))
		goto close_channel;

	if(ret = map_channels(&fd_pairs))
		goto close_channel;
	
	ret = read_channels(&fd_pairs);

	ret |= unmap_channels(&fd_pairs);

close_channel:
	close_channel_trace_pairs(&fd_pairs);

	return ret;
}
Commit	Line	Data
617de8e1	1	/* lttd
	2	*
	3	* Linux Trace Toolkit Daemon
	4	*
	5	* This is a simple daemon that reads a few relayfs channels and save them in a
	6	* trace.
	7	*
	8	*
	9	* Copyright 2005 -
	10	* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
	11	*/
	12
0bb647f5	13	#ifdef HAVE_CONFIG_H
469206ed	14	#include <config.h>
0bb647f5	15	#endif
0bb647f5	16
e54e1d5d	17	#define _REENTRANT
0bb647f5	18	#define _GNU_SOURCE
e54e1d5d	19	#include <features.h>
617de8e1	20	#include <stdio.h>
1d483eea	21	#include <unistd.h>
617de8e1	22	#include <errno.h>
	23	#include <sys/types.h>
	24	#include <sys/stat.h>
617de8e1	25	#include <stdlib.h>
	26	#include <dirent.h>
	27	#include <string.h>
90ccaa9a	28	#include <fcntl.h>
90ccaa9a	29	#include <sys/poll.h>
1d483eea	30	#include <sys/mman.h>
1d483eea	31	#include <signal.h>
e54e1d5d	32	#include <pthread.h>
1d483eea	33
	34	/* Relayfs IOCTL */
	35	#include <asm/ioctl.h>
	36	#include <asm/types.h>
	37
	38	/* Get the next sub buffer that can be read. */
	39	#define RELAYFS_GET_SUBBUF _IOR(0xF4, 0x00,__u32)
	40	/* Release the oldest reserved (by "get") sub buffer. */
13ac5fb1	41	#define RELAYFS_PUT_SUBBUF _IOW(0xF4, 0x01,__u32)
1d483eea	42	/* returns the number of sub buffers in the per cpu channel. */
	43	#define RELAYFS_GET_N_SUBBUFS _IOR(0xF4, 0x02,__u32)
	44	/* returns the size of the sub buffers. */
	45	#define RELAYFS_GET_SUBBUF_SIZE _IOR(0xF4, 0x03,__u32)
	46
	47
617de8e1	48
	49	enum {
	50	GET_SUBBUF,
	51	PUT_SUBBUF,
	52	GET_N_BUBBUFS,
	53	GET_SUBBUF_SIZE
	54	};
	55
	56	struct fd_pair {
	57	int channel;
	58	int trace;
1d483eea	59	unsigned int n_subbufs;
	60	unsigned int subbuf_size;
	61	void *mmap;
617de8e1	62	};
	63
	64	struct channel_trace_fd {
	65	struct fd_pair *pair;
	66	int num_pairs;
	67	};
	68
	69	static char *trace_name = NULL;
	70	static char *channel_name = NULL;
	71	static int daemon_mode = 0;
90ccaa9a	72	static int append_mode = 0;
e54e1d5d	73	static unsigned long num_threads = 1;
1d483eea	74	volatile static int quit_program = 0; /* For signal handler */
617de8e1	75
	76	/* Args :
	77	*
	78	* -t directory Directory name of the trace to write to. Will be created.
	79	* -c directory Root directory of the relayfs trace channels.
	80	* -d Run in background (daemon).
90ccaa9a	81	* -a Trace append mode.
ce2b5176	82	* -s Send SIGUSR1 to parent when ready for IO.
617de8e1	83	*/
	84	void show_arguments(void)
	85	{
	86	printf("Please use the following arguments :\n");
	87	printf("\n");
	88	printf("-t directory Directory name of the trace to write to.\n"
	89	" It will be created.\n");
	90	printf("-c directory Root directory of the relayfs trace channels.\n");
	91	printf("-d Run in background (daemon).\n");
90ccaa9a	92	printf("-a Append to an possibly existing trace.\n");
e54e1d5d	93	printf("-n Number of threads to start.\n");
617de8e1	94	printf("\n");
	95	}
	96
	97
	98	/* parse_arguments
	99	*
	100	* Parses the command line arguments.
	101	*
	102	* Returns 1 if the arguments were correct, but doesn't ask for program
	103	* continuation. Returns -1 if the arguments are incorrect, or 0 if OK.
	104	*/
	105	int parse_arguments(int argc, char **argv)
	106	{
	107	int ret = 0;
	108	int argn = 1;
	109
	110	if(argc == 2) {
	111	if(strcmp(argv[1], "-h") == 0) {
	112	return 1;
	113	}
	114	}
	115
90ccaa9a	116	while(argn < argc) {
617de8e1	117
	118	switch(argv[argn][0]) {
	119	case '-':
	120	switch(argv[argn][1]) {
	121	case 't':
90ccaa9a	122	if(argn+1 < argc) {
	123	trace_name = argv[argn+1];
	124	argn++;
	125	}
617de8e1	126	break;
617de8e1	127	case 'c':
90ccaa9a	128	if(argn+1 < argc) {
	129	channel_name = argv[argn+1];
	130	argn++;
	131	}
617de8e1	132	break;
	133	case 'd':
	134	daemon_mode = 1;
	135	break;
90ccaa9a	136	case 'a':
	137	append_mode = 1;
	138	break;
e54e1d5d	139	case 'n':
	140	if(argn+1 < argc) {
	141	num_threads = strtoul(argv[argn+1], NULL, 0);
	142	argn++;
	143	}
	144	break;
617de8e1	145	default:
	146	printf("Invalid argument '%s'.\n", argv[argn]);
	147	printf("\n");
	148	ret = -1;
	149	}
	150	break;
	151	default:
	152	printf("Invalid argument '%s'.\n", argv[argn]);
	153	printf("\n");
	154	ret = -1;
	155	}
	156	argn++;
	157	}
	158
	159	if(trace_name == NULL) {
	160	printf("Please specify a trace name.\n");
	161	printf("\n");
	162	ret = -1;
	163	}
	164
	165	if(channel_name == NULL) {
	166	printf("Please specify a channel name.\n");
	167	printf("\n");
	168	ret = -1;
	169	}
	170
	171	return ret;
	172	}
	173
	174	void show_info(void)
	175	{
	176	printf("Linux Trace Toolkit Trace Daemon\n");
	177	printf("\n");
	178	printf("Reading from relayfs directory : %s\n", channel_name);
	179	printf("Writing to trace directory : %s\n", trace_name);
	180	printf("\n");
	181	}
	182
	183
1d483eea	184	/* signal handling */
	185
	186	static void handler(int signo)
	187	{
	188	printf("Signal %d received : exiting cleanly\n", signo);
	189	quit_program = 1;
	190	}
	191
	192
	193
617de8e1	194	int open_channel_trace_pairs(char subchannel_name, char subtrace_name,
	195	struct channel_trace_fd *fd_pairs)
	196	{
	197	DIR *channel_dir = opendir(subchannel_name);
	198	struct dirent *entry;
	199	struct stat stat_buf;
	200	int ret;
	201	char path_channel[PATH_MAX];
	202	int path_channel_len;
	203	char *path_channel_ptr;
	204	char path_trace[PATH_MAX];
	205	int path_trace_len;
	206	char *path_trace_ptr;
d304b1dd	207	int open_ret = 0;
617de8e1	208
	209	if(channel_dir == NULL) {
	210	perror(subchannel_name);
d304b1dd	211	open_ret = ENOENT;
d304b1dd	212	goto end;
617de8e1	213	}
617de8e1	214
617de8e1	215	printf("Creating trace subdirectory %s\n", subtrace_name);
	216	ret = mkdir(subtrace_name, S_IRWXU\|S_IRWXG\|S_IRWXO);
	217	if(ret == -1) {
b1e3e7c7	218	if(errno != EEXIST) {
90ccaa9a	219	perror(subtrace_name);
d304b1dd	220	open_ret = -1;
d304b1dd	221	goto end;
90ccaa9a	222	}
617de8e1	223	}
	224
	225	strncpy(path_channel, subchannel_name, PATH_MAX-1);
	226	path_channel_len = strlen(path_channel);
	227	path_channel[path_channel_len] = '/';
	228	path_channel_len++;
	229	path_channel_ptr = path_channel + path_channel_len;
	230
	231	strncpy(path_trace, subtrace_name, PATH_MAX-1);
	232	path_trace_len = strlen(path_trace);
	233	path_trace[path_trace_len] = '/';
	234	path_trace_len++;
	235	path_trace_ptr = path_trace + path_trace_len;
	236
	237	while((entry = readdir(channel_dir)) != NULL) {
	238
	239	if(entry->d_name[0] == '.') continue;
	240
	241	strncpy(path_channel_ptr, entry->d_name, PATH_MAX - path_channel_len);
	242	strncpy(path_trace_ptr, entry->d_name, PATH_MAX - path_trace_len);
	243
	244	ret = stat(path_channel, &stat_buf);
	245	if(ret == -1) {
	246	perror(path_channel);
	247	continue;
	248	}
	249
	250	printf("Channel file : %s\n", path_channel);
	251
	252	if(S_ISDIR(stat_buf.st_mode)) {
	253
	254	printf("Entering channel subdirectory...\n");
	255	ret = open_channel_trace_pairs(path_channel, path_trace, fd_pairs);
	256	if(ret < 0) continue;
90ccaa9a	257	} else if(S_ISREG(stat_buf.st_mode)) {
	258	printf("Opening file.\n");
	259
	260	fd_pairs->pair = realloc(fd_pairs->pair,
	261	++fd_pairs->num_pairs * sizeof(struct fd_pair));
	262
	263	/* Open the channel in read mode */
	264	fd_pairs->pair[fd_pairs->num_pairs-1].channel =
	265	open(path_channel, O_RDONLY \| O_NONBLOCK);
	266	if(fd_pairs->pair[fd_pairs->num_pairs-1].channel == -1) {
	267	perror(path_channel);
469206ed	268	fd_pairs->num_pairs--;
469206ed	269	continue;
90ccaa9a	270	}
	271	/* Open the trace in write mode, only append if append_mode */
	272	ret = stat(path_trace, &stat_buf);
	273	if(ret == 0) {
	274	if(append_mode) {
3357d360	275	printf("Appending to file %s as requested\n", path_trace);
90ccaa9a	276
	277	fd_pairs->pair[fd_pairs->num_pairs-1].trace =
	278	open(path_trace, O_WRONLY\|O_APPEND,
	279	S_IRWXU\|S_IRWXG\|S_IRWXO);
	280
	281	if(fd_pairs->pair[fd_pairs->num_pairs-1].trace == -1) {
	282	perror(path_trace);
	283	}
	284	} else {
	285	printf("File %s exists, cannot open. Try append mode.\n", path_trace);
d304b1dd	286	open_ret = -1;
d304b1dd	287	goto end;
90ccaa9a	288	}
	289	} else {
	290	if(errno == ENOENT) {
	291	fd_pairs->pair[fd_pairs->num_pairs-1].trace =
	292	open(path_trace, O_WRONLY\|O_CREAT\|O_EXCL,
	293	S_IRWXU\|S_IRWXG\|S_IRWXO);
	294	if(fd_pairs->pair[fd_pairs->num_pairs-1].trace == -1) {
	295	perror(path_trace);
	296	}
	297	}
	298	}
617de8e1	299	}
617de8e1	300	}
617de8e1	301
d304b1dd	302	end:
617de8e1	303	closedir(channel_dir);
617de8e1	304
d304b1dd	305	return open_ret;
617de8e1	306	}
617de8e1	307
1d483eea	308
	309	int read_subbuffer(struct fd_pair *pair)
	310	{
4f31148b	311	unsigned int consumed_old;
469206ed	312	int err, ret;
1d483eea	313
1d483eea	314
469206ed	315	err = ioctl(pair->channel, RELAYFS_GET_SUBBUF,
4f31148b	316	&consumed_old);
4f31148b	317	printf("cookie : %u\n", consumed_old);
469206ed	318	if(err != 0) {
1d483eea	319	perror("Error in reserving sub buffer");
469206ed	320	ret = -EPERM;
469206ed	321	goto get_error;
1d483eea	322	}
469206ed	323
469206ed	324	err = TEMP_FAILURE_RETRY(write(pair->trace,
e4bed64a	325	pair->mmap
e4bed64a	326	+ (consumed_old & ((pair->n_subbufs * pair->subbuf_size)-1)),
1d483eea	327	pair->subbuf_size));
469206ed	328
469206ed	329	if(err < 0) {
1d483eea	330	perror("Error in writing to file");
469206ed	331	ret = err;
469206ed	332	goto write_error;
1d483eea	333	}
	334
	335
469206ed	336	write_error:
4f31148b	337	err = ioctl(pair->channel, RELAYFS_PUT_SUBBUF, &consumed_old);
469206ed	338	if(err != 0) {
4f31148b	339	if(errno == -EFAULT) {
	340	perror("Error in unreserving sub buffer");
	341	ret = -EFAULT;
	342	} else if(errno == -EIO) {
	343	perror("Reader has been pushed by the writer, last subbuffer corrupted.");
ec8cce5a	344	/* FIXME : we may delete the last written buffer if we wish. */
4f31148b	345	ret = -EIO;
4f31148b	346	}
469206ed	347	goto get_error;
1d483eea	348	}
1d483eea	349
469206ed	350	get_error:
469206ed	351	return ret;
1d483eea	352	}
	353
	354
617de8e1	355
e54e1d5d	356	int map_channels(struct channel_trace_fd *fd_pairs)
617de8e1	357	{
1d483eea	358	int i,j;
e54e1d5d	359	int ret=0;
1d483eea	360
469206ed	361	if(fd_pairs->num_pairs <= 0) {
	362	printf("No channel to read\n");
	363	goto end;
	364	}
	365
1d483eea	366	/* Get the subbuf sizes and number */
	367
	368	for(i=0;i<fd_pairs->num_pairs;i++) {
	369	struct fd_pair *pair = &fd_pairs->pair[i];
90ccaa9a	370
1d483eea	371	ret = ioctl(pair->channel, RELAYFS_GET_N_SUBBUFS,
	372	&pair->n_subbufs);
	373	if(ret != 0) {
	374	perror("Error in getting the number of subbuffers");
	375	goto end;
	376	}
	377	ret = ioctl(pair->channel, RELAYFS_GET_SUBBUF_SIZE,
	378	&pair->subbuf_size);
	379	if(ret != 0) {
	380	perror("Error in getting the size of the subbuffers");
	381	goto end;
	382	}
	383	}
	384
	385	/* Mmap each FD */
	386	for(i=0;i<fd_pairs->num_pairs;i++) {
	387	struct fd_pair *pair = &fd_pairs->pair[i];
	388
	389	pair->mmap = mmap(0, pair->subbuf_size * pair->n_subbufs, PROT_READ,
	390	MAP_SHARED, pair->channel, 0);
	391	if(pair->mmap == MAP_FAILED) {
	392	perror("Mmap error");
	393	goto munmap;
	394	}
	395	}
	396
	397
e54e1d5d	398	/* Error handling */
	399	/* munmap only the successfully mmapped indexes */
	400	munmap:
	401	/* Munmap each FD */
	402	for(j=0;j<i;j++) {
	403	struct fd_pair *pair = &fd_pairs->pair[j];
	404	int err_ret;
	405
	406	err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs);
	407	if(err_ret != 0) {
	408	perror("Error in munmap");
	409	}
	410	ret \|= err_ret;
	411	}
	412
	413	end:
	414	return ret;
	415
	416
	417	}
	418
	419
	420	int unmap_channels(struct channel_trace_fd *fd_pairs)
	421	{
	422	int j;
	423	int ret=0;
	424
	425	/* Munmap each FD */
	426	for(j=0;j<fd_pairs->num_pairs;j++) {
	427	struct fd_pair *pair = &fd_pairs->pair[j];
	428	int err_ret;
	429
	430	err_ret = munmap(pair->mmap, pair->subbuf_size * pair->n_subbufs);
	431	if(err_ret != 0) {
	432	perror("Error in munmap");
	433	}
	434	ret \|= err_ret;
	435	}
	436
	437	return ret;
	438	}
	439
	440
	441	/* read_channels
	442	*
	443	* Read the relayfs channels and write them in the paired tracefiles.
	444	*
	445	* @fd_pairs : paired channels and trace files.
	446	*
	447	* returns 0 on success, -1 on error.
	448	*
	449	* Note that the high priority polled channels are consumed first. We then poll
	450	* again to see if these channels are still in priority. Only when no
	451	* high priority channel is left, we start reading low priority channels.
	452	*
	453	* Note that a channel is considered high priority when the buffer is almost
	454	* full.
	455	*/
	456
	457	int read_channels(struct channel_trace_fd *fd_pairs)
	458	{
	459	struct pollfd *pollfd;
	460	int i,j;
	461	int num_rdy, num_hup;
462	int high_prio;
463	int ret;
464
1d483eea	465	/* Start polling the FD */
1d483eea	466
90ccaa9a	467	pollfd = malloc(fd_pairs->num_pairs * sizeof(struct pollfd));
90ccaa9a	468
1d483eea	469	/* Note : index in pollfd is the same index as fd_pair->pair */
90ccaa9a	470	for(i=0;i<fd_pairs->num_pairs;i++) {
	471	pollfd[i].fd = fd_pairs->pair[i].channel;
	472	pollfd[i].events = POLLIN\|POLLPRI;
	473	}
	474
	475	while(1) {
4f45ea55	476	high_prio = 0;
1d483eea	477	num_hup = 0;
	478	#ifdef DEBUG
	479	printf("Press a key for next poll...\n");
	480	char buf[1];
	481	read(STDIN_FILENO, &buf, 1);
469206ed	482	printf("Next poll (polling %d fd) :\n", fd_pairs->num_pairs);
1d483eea	483	#endif //DEBUG
	484
	485	/* Have we received a signal ? */
	486	if(quit_program) break;
	487
90ccaa9a	488	num_rdy = poll(pollfd, fd_pairs->num_pairs, -1);
	489	if(num_rdy == -1) {
	490	perror("Poll error");
1d483eea	491	goto free_fd;
90ccaa9a	492	}
	493
	494	printf("Data received\n");
	495
	496	for(i=0;i<fd_pairs->num_pairs;i++) {
	497	switch(pollfd[i].revents) {
	498	case POLLERR:
	499	printf("Error returned in polling fd %d.\n", pollfd[i].fd);
1d483eea	500	num_hup++;
90ccaa9a	501	break;
	502	case POLLHUP:
	503	printf("Polling fd %d tells it has hung up.\n", pollfd[i].fd);
1d483eea	504	num_hup++;
90ccaa9a	505	break;
	506	case POLLNVAL:
	507	printf("Polling fd %d tells fd is not open.\n", pollfd[i].fd);
1d483eea	508	num_hup++;
90ccaa9a	509	break;
90ccaa9a	510	case POLLPRI:
1d483eea	511	printf("Urgent read on fd %d\n", pollfd[i].fd);
90ccaa9a	512	/* Take care of high priority channels first. */
4f45ea55	513	high_prio = 1;
1d483eea	514	ret \|= read_subbuffer(&fd_pairs->pair[i]);
90ccaa9a	515	break;
4f45ea55	516	}
90ccaa9a	517	}
1d483eea	518	/* If every FD has hung up, we end the read loop here */
1d483eea	519	if(num_hup == fd_pairs->num_pairs) break;
90ccaa9a	520
4f45ea55	521	if(!high_prio) {
	522	for(i=0;i<fd_pairs->num_pairs;i++) {
	523	switch(pollfd[i].revents) {
	524	case POLLIN:
	525	/* Take care of low priority channels. */
1d483eea	526	printf("Normal read on fd %d\n", pollfd[i].fd);
1d483eea	527	ret \|= read_subbuffer(&fd_pairs->pair[i]);
4f45ea55	528	break;
	529	}
	530	}
90ccaa9a	531	}
	532
	533	}
	534
1d483eea	535	free_fd:
90ccaa9a	536	free(pollfd);
90ccaa9a	537
1d483eea	538	end:
1d483eea	539	return ret;
617de8e1	540	}
	541
	542
	543	void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs)
	544	{
90ccaa9a	545	int i;
90ccaa9a	546	int ret;
617de8e1	547
90ccaa9a	548	for(i=0;i<fd_pairs->num_pairs;i++) {
	549	ret = close(fd_pairs->pair[i].channel);
	550	if(ret == -1) perror("Close error on channel");
	551	ret = close(fd_pairs->pair[i].trace);
	552	if(ret == -1) perror("Close error on trace");
	553	}
	554	free(fd_pairs->pair);
617de8e1	555	}
	556
	557	int main(int argc, char ** argv)
	558	{
e54e1d5d	559	int ret = 0;
617de8e1	560	struct channel_trace_fd fd_pairs = { NULL, 0 };
1d483eea	561	struct sigaction act;
617de8e1	562
	563	ret = parse_arguments(argc, argv);
	564
	565	if(ret != 0) show_arguments();
	566	if(ret < 0) return EINVAL;
	567	if(ret > 0) return 0;
	568
	569	show_info();
	570
	571	if(daemon_mode) {
2253bb8e	572	ret = daemon(0, 0);
	573
	574	if(ret == -1) {
	575	perror("An error occured while daemonizing.");
	576	exit(-1);
	577	}
	578	}
617de8e1	579
1d483eea	580	/* Connect the signal handlers */
	581	act.sa_handler = handler;
	582	act.sa_flags = 0;
	583	sigemptyset(&(act.sa_mask));
	584	sigaddset(&(act.sa_mask), SIGTERM);
	585	sigaddset(&(act.sa_mask), SIGQUIT);
	586	sigaddset(&(act.sa_mask), SIGINT);
	587	sigaction(SIGTERM, &act, NULL);
	588	sigaction(SIGQUIT, &act, NULL);
	589	sigaction(SIGINT, &act, NULL);
	590
e54e1d5d	591
617de8e1	592	if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs))
90ccaa9a	593	goto close_channel;
617de8e1	594
e54e1d5d	595	if(ret = map_channels(&fd_pairs))
	596	goto close_channel;
	597
617de8e1	598	ret = read_channels(&fd_pairs);
617de8e1	599
e54e1d5d	600	ret \|= unmap_channels(&fd_pairs);
e54e1d5d	601
90ccaa9a	602	close_channel:
617de8e1	603	close_channel_trace_pairs(&fd_pairs);
617de8e1	604
617de8e1	605	return ret;
617de8e1	606	}