common/common.c

   1 /*
   2  * Babeltrace common functions
   3  *
   4  * Copyright 2016 Philippe Proulx <pproulx@efficios.com>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <sys/types.h>
  28 #include <pwd.h>
  29 #include <unistd.h>
  30 #include <assert.h>
  31 #include <glib.h>
  32 #include <babeltrace/babeltrace-internal.h>
  33 #include <babeltrace/common-internal.h>
  34
  35 #define SYSTEM_PLUGIN_PATH      INSTALL_LIBDIR "/babeltrace/plugins"
  36 #define HOME_ENV_VAR            "HOME"
  37 #define HOME_PLUGIN_SUBPATH     "/.local/lib/babeltrace/plugins"
  38
  39 BT_HIDDEN
  40 const char *bt_common_get_system_plugin_path(void)
  41 {
  42         return SYSTEM_PLUGIN_PATH;
  43 }
  44
  45 BT_HIDDEN
  46 bool bt_common_is_setuid_setgid(void)
  47 {
  48         return (geteuid() != getuid() || getegid() != getgid());
  49 }
  50
  51 static char *bt_secure_getenv(const char *name)
  52 {
  53         if (bt_common_is_setuid_setgid()) {
  54                 printf_error("Disregarding %s environment variable for setuid/setgid binary",
  55                         name);
  56                 return NULL;
  57         }
  58         return getenv(name);
  59 }
  60
  61 static const char *get_home_dir(void)
  62 {
  63         char *val = NULL;
  64         struct passwd *pwd;
  65
  66         val = bt_secure_getenv(HOME_ENV_VAR);
  67         if (val) {
  68                 goto end;
  69         }
  70         /* Fallback on password file. */
  71         pwd = getpwuid(getuid());
  72         if (!pwd) {
  73                 goto end;
  74         }
  75         val = pwd->pw_dir;
  76 end:
  77         return val;
  78 }
  79
  80 BT_HIDDEN
  81 char *bt_common_get_home_plugin_path(void)
  82 {
  83         char *path = NULL;
  84         const char *home_dir;
  85
  86         home_dir = get_home_dir();
  87         if (!home_dir) {
  88                 goto end;
  89         }
  90
  91         if (strlen(home_dir) + strlen(HOME_PLUGIN_SUBPATH) + 1 >= PATH_MAX) {
  92                 printf_error("Home directory path is too long: `%s`\n",
  93                         home_dir);
  94                 goto end;
  95         }
  96
  97         path = malloc(PATH_MAX);
  98         if (!path) {
  99                 goto end;
 100         }
 101
 102         strcpy(path, home_dir);
 103         strcat(path, HOME_PLUGIN_SUBPATH);
 104
 105 end:
 106         return path;
 107 }
 108
 109 BT_HIDDEN
 110 int bt_common_append_plugin_path_dirs(const char *paths, GPtrArray *dirs)
 111 {
 112         int ret = 0;
 113         const char *at;
 114         const char *end;
 115         size_t init_dirs_len;
 116
 117         assert(dirs);
 118         init_dirs_len = dirs->len;
 119
 120         if (!paths) {
 121                 /* Nothing to append */
 122                 goto end;
 123         }
 124
 125         at = paths;
 126         end = paths + strlen(paths);
 127
 128         while (at < end) {
 129                 GString *path;
 130                 const char *next_colon;
 131
 132                 next_colon = strchr(at, ':');
 133                 if (next_colon == at) {
 134                         /*
 135                          * Empty path: try next character (supported
 136                          * to conform to the typical parsing of $PATH).
 137                          */
 138                         at++;
 139                         continue;
 140                 } else if (!next_colon) {
 141                         /* No more colon: use the remaining */
 142                         next_colon = paths + strlen(paths);
 143                 }
 144
 145                 path = g_string_new(NULL);
 146                 if (!path) {
 147                         goto error;
 148                 }
 149
 150                 g_string_append_len(path, at, next_colon - at);
 151                 at = next_colon + 1;
 152                 g_ptr_array_add(dirs, path);
 153         }
 154
 155         goto end;
 156
 157 error:
 158         ret = -1;
 159
 160         /* Remove the new entries in dirs */
 161         while (dirs->len > init_dirs_len) {
 162                 g_ptr_array_remove_index(dirs, init_dirs_len);
 163         }
 164
 165 end:
 166         return ret;
 167 }
 168
 169 BT_HIDDEN
 170 bool bt_common_colors_supported(void)
 171 {
 172         static bool supports_colors = false;
 173         static bool supports_colors_set = false;
 174         const char *term;
 175
 176         if (supports_colors_set) {
 177                 goto end;
 178         }
 179
 180         supports_colors_set = true;
 181
 182         term = getenv("TERM");
 183         if (!term) {
 184                 goto end;
 185         }
 186
 187         if (strncmp(term, "xterm", 5) != 0 &&
 188                         strncmp(term, "rxvt", 4) != 0 &&
 189                         strncmp(term, "konsole", 7) != 0 &&
 190                         strncmp(term, "gnome", 5) != 0) {
 191                 goto end;
 192         }
 193
 194         if (!isatty(1)) {
 195                 goto end;
 196         }
 197
 198         supports_colors = true;
 199
 200 end:
 201         return supports_colors;
 202 }
 203
 204 BT_HIDDEN
 205 const char *bt_common_color_reset(void)
 206 {
 207         return bt_common_colors_supported() ? BT_COMMON_COLOR_RESET : "";
 208 }
 209
 210 BT_HIDDEN
 211 const char *bt_common_color_bold(void)
 212 {
 213         return bt_common_colors_supported() ? BT_COMMON_COLOR_BOLD : "";
 214 }
 215
 216 BT_HIDDEN
 217 const char *bt_common_color_fg_default(void)
 218 {
 219         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_DEFAULT : "";
 220 }
 221
 222 BT_HIDDEN
 223 const char *bt_common_color_fg_red(void)
 224 {
 225         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_RED : "";
 226 }
 227
 228 BT_HIDDEN
 229 const char *bt_common_color_fg_green(void)
 230 {
 231         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_GREEN : "";
 232 }
 233
 234 BT_HIDDEN
 235 const char *bt_common_color_fg_yellow(void)
 236 {
 237         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_YELLOW : "";
 238 }
 239
 240 BT_HIDDEN
 241 const char *bt_common_color_fg_blue(void)
 242 {
 243         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_BLUE : "";
 244 }
 245
 246 BT_HIDDEN
 247 const char *bt_common_color_fg_magenta(void)
 248 {
 249         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_MAGENTA : "";
 250 }
 251
 252 BT_HIDDEN
 253 const char *bt_common_color_fg_cyan(void)
 254 {
 255         return bt_common_colors_supported() ? BT_COMMON_COLOR_FG_CYAN : "";
 256 }
 257
 258 BT_HIDDEN
 259 const char *bt_common_color_fg_light_gray(void)
 260 {
 261         return bt_common_colors_supported() ?
 262                 BT_COMMON_COLOR_FG_LIGHT_GRAY : "";
 263 }
 264
 265 BT_HIDDEN
 266 const char *bt_common_color_bg_default(void)
 267 {
 268         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_DEFAULT : "";
 269 }
 270
 271 BT_HIDDEN
 272 const char *bt_common_color_bg_red(void)
 273 {
 274         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_RED : "";
 275 }
 276
 277 BT_HIDDEN
 278 const char *bt_common_color_bg_green(void)
 279 {
 280         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_GREEN : "";
 281 }
 282
 283 BT_HIDDEN
 284 const char *bt_common_color_bg_yellow(void)
 285 {
 286         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_YELLOW : "";
 287 }
 288
 289 BT_HIDDEN
 290 const char *bt_common_color_bg_blue(void)
 291 {
 292         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_BLUE : "";
 293 }
 294
 295 BT_HIDDEN
 296 const char *bt_common_color_bg_magenta(void)
 297 {
 298         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_MAGENTA : "";
 299 }
 300
 301 BT_HIDDEN
 302 const char *bt_common_color_bg_cyan(void)
 303 {
 304         return bt_common_colors_supported() ? BT_COMMON_COLOR_BG_CYAN : "";
 305 }
 306
 307 BT_HIDDEN
 308 const char *bt_common_color_bg_light_gray(void)
 309 {
 310         return bt_common_colors_supported() ?
 311                 BT_COMMON_COLOR_BG_LIGHT_GRAY : "";
 312 }