| 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 | |
| 13 | #include <stdio.h> |
| 14 | #include <errno.h> |
| 15 | #include <sys/types.h> |
| 16 | #include <sys/stat.h> |
| 17 | #include <unistd.h> |
| 18 | #include <stdlib.h> |
| 19 | #include <dirent.h> |
| 20 | #include <string.h> |
| 21 | |
| 22 | |
| 23 | enum { |
| 24 | GET_SUBBUF, |
| 25 | PUT_SUBBUF, |
| 26 | GET_N_BUBBUFS, |
| 27 | GET_SUBBUF_SIZE |
| 28 | }; |
| 29 | |
| 30 | struct fd_pair { |
| 31 | int channel; |
| 32 | int trace; |
| 33 | }; |
| 34 | |
| 35 | struct channel_trace_fd { |
| 36 | struct fd_pair *pair; |
| 37 | int num_pairs; |
| 38 | }; |
| 39 | |
| 40 | static char *trace_name = NULL; |
| 41 | static char *channel_name = NULL; |
| 42 | static int daemon_mode = 0; |
| 43 | |
| 44 | |
| 45 | /* Args : |
| 46 | * |
| 47 | * -t directory Directory name of the trace to write to. Will be created. |
| 48 | * -c directory Root directory of the relayfs trace channels. |
| 49 | * -d Run in background (daemon). |
| 50 | */ |
| 51 | void show_arguments(void) |
| 52 | { |
| 53 | printf("Please use the following arguments :\n"); |
| 54 | printf("\n"); |
| 55 | printf("-t directory Directory name of the trace to write to.\n" |
| 56 | " It will be created.\n"); |
| 57 | printf("-c directory Root directory of the relayfs trace channels.\n"); |
| 58 | printf("-d Run in background (daemon).\n"); |
| 59 | printf("\n"); |
| 60 | } |
| 61 | |
| 62 | |
| 63 | /* parse_arguments |
| 64 | * |
| 65 | * Parses the command line arguments. |
| 66 | * |
| 67 | * Returns 1 if the arguments were correct, but doesn't ask for program |
| 68 | * continuation. Returns -1 if the arguments are incorrect, or 0 if OK. |
| 69 | */ |
| 70 | int parse_arguments(int argc, char **argv) |
| 71 | { |
| 72 | int ret = 0; |
| 73 | int argn = 1; |
| 74 | |
| 75 | if(argc == 2) { |
| 76 | if(strcmp(argv[1], "-h") == 0) { |
| 77 | return 1; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | while(argn < argc-1) { |
| 82 | |
| 83 | switch(argv[argn][0]) { |
| 84 | case '-': |
| 85 | switch(argv[argn][1]) { |
| 86 | case 't': |
| 87 | trace_name = argv[argn+1]; |
| 88 | argn++; |
| 89 | break; |
| 90 | case 'c': |
| 91 | channel_name = argv[argn+1]; |
| 92 | argn++; |
| 93 | break; |
| 94 | case 'd': |
| 95 | daemon_mode = 1; |
| 96 | break; |
| 97 | default: |
| 98 | printf("Invalid argument '%s'.\n", argv[argn]); |
| 99 | printf("\n"); |
| 100 | ret = -1; |
| 101 | } |
| 102 | break; |
| 103 | default: |
| 104 | printf("Invalid argument '%s'.\n", argv[argn]); |
| 105 | printf("\n"); |
| 106 | ret = -1; |
| 107 | } |
| 108 | argn++; |
| 109 | } |
| 110 | |
| 111 | if(trace_name == NULL) { |
| 112 | printf("Please specify a trace name.\n"); |
| 113 | printf("\n"); |
| 114 | ret = -1; |
| 115 | } |
| 116 | |
| 117 | if(channel_name == NULL) { |
| 118 | printf("Please specify a channel name.\n"); |
| 119 | printf("\n"); |
| 120 | ret = -1; |
| 121 | } |
| 122 | |
| 123 | return ret; |
| 124 | } |
| 125 | |
| 126 | void show_info(void) |
| 127 | { |
| 128 | printf("Linux Trace Toolkit Trace Daemon\n"); |
| 129 | printf("\n"); |
| 130 | printf("Reading from relayfs directory : %s\n", channel_name); |
| 131 | printf("Writing to trace directory : %s\n", trace_name); |
| 132 | printf("\n"); |
| 133 | } |
| 134 | |
| 135 | |
| 136 | int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name, |
| 137 | struct channel_trace_fd *fd_pairs) |
| 138 | { |
| 139 | DIR *channel_dir = opendir(subchannel_name); |
| 140 | struct dirent *entry; |
| 141 | struct stat stat_buf; |
| 142 | int ret; |
| 143 | char path_channel[PATH_MAX]; |
| 144 | int path_channel_len; |
| 145 | char *path_channel_ptr; |
| 146 | char path_trace[PATH_MAX]; |
| 147 | int path_trace_len; |
| 148 | char *path_trace_ptr; |
| 149 | |
| 150 | if(channel_dir == NULL) { |
| 151 | perror(subchannel_name); |
| 152 | return ENOENT; |
| 153 | } |
| 154 | |
| 155 | //FIXME : check if the directory already exist, and ask the user if he wants |
| 156 | //to append to the traces. |
| 157 | printf("Creating trace subdirectory %s\n", subtrace_name); |
| 158 | ret = mkdir(subtrace_name, S_IRWXU|S_IRWXG|S_IRWXO); |
| 159 | if(ret == -1) { |
| 160 | perror(subtrace_name); |
| 161 | return -1; |
| 162 | } |
| 163 | |
| 164 | strncpy(path_channel, subchannel_name, PATH_MAX-1); |
| 165 | path_channel_len = strlen(path_channel); |
| 166 | path_channel[path_channel_len] = '/'; |
| 167 | path_channel_len++; |
| 168 | path_channel_ptr = path_channel + path_channel_len; |
| 169 | |
| 170 | strncpy(path_trace, subtrace_name, PATH_MAX-1); |
| 171 | path_trace_len = strlen(path_trace); |
| 172 | path_trace[path_trace_len] = '/'; |
| 173 | path_trace_len++; |
| 174 | path_trace_ptr = path_trace + path_trace_len; |
| 175 | |
| 176 | while((entry = readdir(channel_dir)) != NULL) { |
| 177 | |
| 178 | if(entry->d_name[0] == '.') continue; |
| 179 | |
| 180 | strncpy(path_channel_ptr, entry->d_name, PATH_MAX - path_channel_len); |
| 181 | strncpy(path_trace_ptr, entry->d_name, PATH_MAX - path_trace_len); |
| 182 | |
| 183 | ret = stat(path_channel, &stat_buf); |
| 184 | if(ret == -1) { |
| 185 | perror(path_channel); |
| 186 | continue; |
| 187 | } |
| 188 | |
| 189 | printf("Channel file : %s\n", path_channel); |
| 190 | |
| 191 | if(S_ISDIR(stat_buf.st_mode)) { |
| 192 | |
| 193 | printf("Entering channel subdirectory...\n"); |
| 194 | ret = open_channel_trace_pairs(path_channel, path_trace, fd_pairs); |
| 195 | if(ret < 0) continue; |
| 196 | } |
| 197 | |
| 198 | } |
| 199 | |
| 200 | closedir(channel_dir); |
| 201 | |
| 202 | return 0; |
| 203 | } |
| 204 | |
| 205 | |
| 206 | int read_channels(struct channel_trace_fd *fd_pairs) |
| 207 | { |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | |
| 212 | void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs) |
| 213 | { |
| 214 | |
| 215 | } |
| 216 | |
| 217 | int main(int argc, char ** argv) |
| 218 | { |
| 219 | int ret; |
| 220 | pid_t pid; |
| 221 | struct channel_trace_fd fd_pairs = { NULL, 0 }; |
| 222 | |
| 223 | ret = parse_arguments(argc, argv); |
| 224 | |
| 225 | if(ret != 0) show_arguments(); |
| 226 | if(ret < 0) return EINVAL; |
| 227 | if(ret > 0) return 0; |
| 228 | |
| 229 | show_info(); |
| 230 | |
| 231 | if(daemon_mode) { |
| 232 | pid = fork(); |
| 233 | |
| 234 | if(pid > 0) { |
| 235 | /* parent */ |
| 236 | return 0; |
| 237 | } else if(pid < 0) { |
| 238 | /* error */ |
| 239 | printf("An error occured while forking.\n"); |
| 240 | return -1; |
| 241 | } |
| 242 | /* else, we are the child, continue... */ |
| 243 | } |
| 244 | |
| 245 | if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs)) |
| 246 | goto end_main; |
| 247 | |
| 248 | ret = read_channels(&fd_pairs); |
| 249 | |
| 250 | close_channel_trace_pairs(&fd_pairs); |
| 251 | |
| 252 | end_main: |
| 253 | |
| 254 | return ret; |
| 255 | } |