[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>
 */

#define _GNU_SOURCE
#include <config.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>

/* 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;
static int	sig_parent = 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 SIGIO 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("-s            Send SIGIO to parent when ready for IO.\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 's':
						sig_parent = 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;

	if(channel_dir == NULL) {
		perror(subchannel_name);
		return ENOENT;
	}

	printf("Creating trace subdirectory %s\n", subtrace_name);
	ret = mkdir(subtrace_name, S_IRWXU|S_IRWXG|S_IRWXO);
	if(ret == -1) {
		if(errno == EEXIST && append_mode) {
			printf("Appending to directory %s as resquested\n", subtrace_name);
		} else {
			perror(subtrace_name);
			return -1;
		}
	}

	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);
					return -1;
				}
			} 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);
					}
				}
			}
		}
	}
	
	closedir(channel_dir);

	return 0;
}


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;
	}

	/* Signal the parent that ready for IO */
	if(sig_parent) kill(getppid(), SIGIO);

	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;
	pid_t pid;
	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) {
		pid = fork();
		
		if(pid > 0) {
			/* parent */
			return 0;
		} else if(pid < 0) {
			/* error */
			printf("An error occured while forking.\n");
			return -1;
		}
		/* else, we are the child, continue... */
	}

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