| 1 | /* liblttdutils |
| 2 | * |
| 3 | * Linux Trace Toolkit utility library |
| 4 | * |
| 5 | * This is a simple daemon implementation that reads a few relay+debugfs |
| 6 | * channels and save them in a trace. |
| 7 | * |
| 8 | * CPU hot-plugging is supported using inotify. |
| 9 | * |
| 10 | * Copyright 2005 - |
| 11 | * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
| 12 | * Copyright 2010 - |
| 13 | * Michael Sills-Lavoie <michael.sills-lavoie@polymtl.ca> |
| 14 | * Oumarou Dicko <oumarou.dicko@polymtl.ca> |
| 15 | */ |
| 16 | |
| 17 | #ifdef HAVE_CONFIG_H |
| 18 | #include <config.h> |
| 19 | #endif |
| 20 | |
| 21 | #define _REENTRANT |
| 22 | #define _GNU_SOURCE |
| 23 | |
| 24 | #include <stdio.h> |
| 25 | #include <stdlib.h> |
| 26 | #include <string.h> |
| 27 | #include <errno.h> |
| 28 | #include <fcntl.h> |
| 29 | #include <dirent.h> |
| 30 | #include <pthread.h> |
| 31 | #include <sys/stat.h> |
| 32 | |
| 33 | #include "liblttdutils.h" |
| 34 | |
| 35 | struct liblttdutils_channel_data { |
| 36 | int trace; |
| 37 | }; |
| 38 | |
| 39 | struct liblttdutils_data { |
| 40 | char path_trace[PATH_MAX]; |
| 41 | char *end_path_trace; |
| 42 | int path_trace_len; |
| 43 | int append_mode; |
| 44 | int verbose_mode; |
| 45 | }; |
| 46 | |
| 47 | static __thread int thread_pipe[2]; |
| 48 | |
| 49 | #define printf_verbose(fmt, args...) \ |
| 50 | do { \ |
| 51 | if (callbacks_data->verbose_mode) \ |
| 52 | printf(fmt, ##args); \ |
| 53 | } while (0) |
| 54 | |
| 55 | int liblttdutils_local_on_open_channel(struct liblttd_callbacks *data, struct fd_pair *pair, char *relative_channel_path) |
| 56 | { |
| 57 | int open_ret = 0; |
| 58 | int ret; |
| 59 | struct stat stat_buf; |
| 60 | struct liblttdutils_channel_data *channel_data; |
| 61 | |
| 62 | pair->user_data = malloc(sizeof(struct liblttdutils_channel_data)); |
| 63 | channel_data = pair->user_data; |
| 64 | |
| 65 | struct liblttdutils_data* callbacks_data = data->user_data; |
| 66 | |
| 67 | strncpy(callbacks_data->end_path_trace, relative_channel_path, PATH_MAX - callbacks_data->path_trace_len); |
| 68 | printf_verbose("Creating trace file %s\n", callbacks_data->path_trace); |
| 69 | |
| 70 | ret = stat(callbacks_data->path_trace, &stat_buf); |
| 71 | if(ret == 0) { |
| 72 | if(callbacks_data->append_mode) { |
| 73 | printf_verbose("Appending to file %s as requested\n", |
| 74 | callbacks_data->path_trace); |
| 75 | |
| 76 | channel_data->trace = open(callbacks_data->path_trace, O_WRONLY, S_IRWXU|S_IRWXG|S_IRWXO); |
| 77 | if(channel_data->trace == -1) { |
| 78 | perror(callbacks_data->path_trace); |
| 79 | open_ret = -1; |
| 80 | goto end; |
| 81 | } |
| 82 | ret = lseek(channel_data->trace, 0, SEEK_END); |
| 83 | if (ret < 0) { |
| 84 | perror(callbacks_data->path_trace); |
| 85 | open_ret = -1; |
| 86 | close(channel_data->trace); |
| 87 | goto end; |
| 88 | } |
| 89 | } else { |
| 90 | printf("File %s exists, cannot open. Try append mode.\n", callbacks_data->path_trace); |
| 91 | open_ret = -1; |
| 92 | goto end; |
| 93 | } |
| 94 | } else { |
| 95 | if(errno == ENOENT) { |
| 96 | channel_data->trace = |
| 97 | open(callbacks_data->path_trace, O_WRONLY|O_CREAT|O_EXCL, S_IRWXU|S_IRWXG|S_IRWXO); |
| 98 | if(channel_data->trace == -1) { |
| 99 | perror(callbacks_data->path_trace); |
| 100 | open_ret = -1; |
| 101 | goto end; |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | end: |
| 107 | return open_ret; |
| 108 | |
| 109 | } |
| 110 | |
| 111 | int liblttdutils_local_on_close_channel(struct liblttd_callbacks *data, struct fd_pair *pair) |
| 112 | { |
| 113 | int ret; |
| 114 | ret = close(((struct liblttdutils_channel_data *)(pair->user_data))->trace); |
| 115 | free(pair->user_data); |
| 116 | return ret; |
| 117 | } |
| 118 | |
| 119 | int liblttdutils_local_on_new_channels_folder(struct liblttd_callbacks *data, char *relative_folder_path) |
| 120 | { |
| 121 | int ret; |
| 122 | int open_ret = 0; |
| 123 | struct liblttdutils_data* callbacks_data = data->user_data; |
| 124 | |
| 125 | strncpy(callbacks_data->end_path_trace, relative_folder_path, PATH_MAX - callbacks_data->path_trace_len); |
| 126 | printf_verbose("Creating trace subdirectory %s\n", callbacks_data->path_trace); |
| 127 | |
| 128 | ret = mkdir(callbacks_data->path_trace, S_IRWXU|S_IRWXG|S_IRWXO); |
| 129 | if(ret == -1) { |
| 130 | if(errno != EEXIST) { |
| 131 | perror(callbacks_data->path_trace); |
| 132 | open_ret = -1; |
| 133 | goto end; |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | end: |
| 138 | return open_ret; |
| 139 | } |
| 140 | |
| 141 | int liblttdutils_local_on_read_subbuffer(struct liblttd_callbacks *data, struct fd_pair *pair, unsigned int len) |
| 142 | { |
| 143 | long ret; |
| 144 | off_t offset = 0; |
| 145 | |
| 146 | struct liblttdutils_data* callbacks_data = data->user_data; |
| 147 | |
| 148 | while (len > 0) { |
| 149 | printf_verbose("splice chan to pipe offset %lu\n", |
| 150 | (unsigned long)offset); |
| 151 | ret = splice(pair->channel, &offset, thread_pipe[1], NULL, |
| 152 | len, SPLICE_F_MOVE | SPLICE_F_MORE); |
| 153 | printf_verbose("splice chan to pipe ret %ld\n", ret); |
| 154 | if (ret < 0) { |
| 155 | perror("Error in relay splice"); |
| 156 | goto write_error; |
| 157 | } |
| 158 | ret = splice(thread_pipe[0], NULL, |
| 159 | ((struct liblttdutils_channel_data *)(pair->user_data))->trace, |
| 160 | NULL, ret, SPLICE_F_MOVE | SPLICE_F_MORE); |
| 161 | printf_verbose("splice pipe to file %ld\n", ret); |
| 162 | if (ret < 0) { |
| 163 | perror("Error in file splice"); |
| 164 | goto write_error; |
| 165 | } |
| 166 | len -= ret; |
| 167 | } |
| 168 | |
| 169 | write_error: |
| 170 | return ret; |
| 171 | } |
| 172 | |
| 173 | int liblttdutils_local_on_new_thread(struct liblttd_callbacks *data, unsigned long thread_num) |
| 174 | { |
| 175 | int ret; |
| 176 | ret = pipe(thread_pipe); |
| 177 | if (ret < 0) { |
| 178 | perror("Error creating pipe"); |
| 179 | return ret; |
| 180 | } |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | int liblttdutils_local_on_close_thread(struct liblttd_callbacks *data, unsigned long thread_num) |
| 185 | { |
| 186 | close(thread_pipe[0]); /* close read end */ |
| 187 | close(thread_pipe[1]); /* close write end */ |
| 188 | return 0; |
| 189 | } |
| 190 | |
| 191 | int liblttdutils_local_on_trace_end(struct liblttd_instance *instance) |
| 192 | { |
| 193 | struct liblttd_callbacks *callbacks = instance->callbacks; |
| 194 | struct liblttdutils_data *data = callbacks->user_data; |
| 195 | |
| 196 | free(data); |
| 197 | free(callbacks); |
| 198 | } |
| 199 | |
| 200 | struct liblttd_callbacks* liblttdutils_local_new_callbacks(char* trace_name, |
| 201 | int append_mode, int verbose_mode) |
| 202 | { |
| 203 | struct liblttdutils_data *data; |
| 204 | struct liblttd_callbacks *callbacks; |
| 205 | |
| 206 | if(!trace_name) return NULL; |
| 207 | |
| 208 | data = malloc(sizeof(struct liblttdutils_data)); |
| 209 | |
| 210 | strncpy(data->path_trace, trace_name, PATH_MAX-1); |
| 211 | data->path_trace_len = strlen(data->path_trace); |
| 212 | data->end_path_trace = data->path_trace + data->path_trace_len; |
| 213 | data->append_mode = append_mode; |
| 214 | data->verbose_mode = verbose_mode; |
| 215 | |
| 216 | callbacks = malloc(sizeof(struct liblttd_callbacks)); |
| 217 | |
| 218 | callbacks->on_open_channel = liblttdutils_local_on_open_channel; |
| 219 | callbacks->on_close_channel = liblttdutils_local_on_close_channel; |
| 220 | callbacks->on_new_channels_folder = liblttdutils_local_on_new_channels_folder; |
| 221 | callbacks->on_read_subbuffer = liblttdutils_local_on_read_subbuffer; |
| 222 | callbacks->on_trace_end = liblttdutils_local_on_trace_end; |
| 223 | callbacks->on_new_thread = liblttdutils_local_on_new_thread; |
| 224 | callbacks->on_close_thread = liblttdutils_local_on_close_thread; |
| 225 | callbacks->user_data = data; |
| 226 | |
| 227 | return callbacks; |
| 228 | } |
| 229 | |