| 1 | /* |
| 2 | * Copyright (C) 2011 EfficiOS Inc. |
| 3 | * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com> |
| 5 | * |
| 6 | * SPDX-License-Identifier: LGPL-2.1-only |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include "error.hpp" |
| 11 | #include "macros.hpp" |
| 12 | #include "spawn-viewer.hpp" |
| 13 | |
| 14 | #include <common/compat/errno.hpp> |
| 15 | |
| 16 | #include <lttng/constant.h> |
| 17 | |
| 18 | #include <stdbool.h> |
| 19 | #include <sys/stat.h> |
| 20 | #include <sys/types.h> |
| 21 | #include <unistd.h> |
| 22 | |
| 23 | /* |
| 24 | * Type is also use as the index in the viewers array. So please, make sure |
| 25 | * your enum value is in the right order in the array below. |
| 26 | */ |
| 27 | enum viewer_type { |
| 28 | VIEWER_BABELTRACE = 0, |
| 29 | VIEWER_BABELTRACE2 = 1, |
| 30 | VIEWER_USER_DEFINED = 2, |
| 31 | }; |
| 32 | |
| 33 | namespace { |
| 34 | const char *babeltrace_bin = CONFIG_BABELTRACE_BIN; |
| 35 | const char *babeltrace2_bin = CONFIG_BABELTRACE2_BIN; |
| 36 | |
| 37 | /* |
| 38 | * This is needed for each viewer since we are using execvp(). |
| 39 | */ |
| 40 | const char *babeltrace_opts[] = { "babeltrace" }; |
| 41 | const char *babeltrace2_opts[] = { "babeltrace2" }; |
| 42 | |
| 43 | const struct viewer { |
| 44 | const char *exec_name; |
| 45 | enum viewer_type type; |
| 46 | } viewers[] = { |
| 47 | { "babeltrace", VIEWER_BABELTRACE }, |
| 48 | { "babeltrace2", VIEWER_BABELTRACE2 }, |
| 49 | { nullptr, VIEWER_USER_DEFINED }, |
| 50 | }; |
| 51 | } /* namespace */ |
| 52 | |
| 53 | static const struct viewer *parse_viewer_option(const char *opt_viewer) |
| 54 | { |
| 55 | if (opt_viewer == nullptr) { |
| 56 | /* Default is babeltrace2 */ |
| 57 | return &(viewers[VIEWER_BABELTRACE2]); |
| 58 | } |
| 59 | |
| 60 | return &(viewers[VIEWER_USER_DEFINED]); |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * Alloc an array of string pointer from a simple string having all options |
| 65 | * seperated by spaces. Also adds the trace path to the arguments. |
| 66 | * |
| 67 | * The returning pointer is ready to be passed to execvp(). |
| 68 | */ |
| 69 | static char **alloc_argv_from_user_opts(char *opts, const char *trace_path) |
| 70 | { |
| 71 | int i = 0, ignore_space = 0; |
| 72 | unsigned int num_opts = 1; |
| 73 | char **argv, *token = opts, *saveptr = nullptr; |
| 74 | |
| 75 | /* Count number of arguments. */ |
| 76 | do { |
| 77 | if (*token == ' ') { |
| 78 | /* Use to ignore consecutive spaces */ |
| 79 | if (!ignore_space) { |
| 80 | num_opts++; |
| 81 | } |
| 82 | ignore_space = 1; |
| 83 | } else { |
| 84 | ignore_space = 0; |
| 85 | } |
| 86 | token++; |
| 87 | } while (*token != '\0'); |
| 88 | |
| 89 | /* Add two here for the NULL terminating element and trace path */ |
| 90 | argv = calloc<char *>(num_opts + 2); |
| 91 | if (argv == nullptr) { |
| 92 | goto error; |
| 93 | } |
| 94 | |
| 95 | token = strtok_r(opts, " ", &saveptr); |
| 96 | while (token != nullptr) { |
| 97 | argv[i] = strdup(token); |
| 98 | if (argv[i] == nullptr) { |
| 99 | goto error; |
| 100 | } |
| 101 | token = strtok_r(nullptr, " ", &saveptr); |
| 102 | i++; |
| 103 | } |
| 104 | |
| 105 | argv[num_opts] = (char *) trace_path; |
| 106 | argv[num_opts + 1] = nullptr; |
| 107 | |
| 108 | return argv; |
| 109 | |
| 110 | error: |
| 111 | if (argv) { |
| 112 | for (i = 0; i < num_opts + 2; i++) { |
| 113 | free(argv[i]); |
| 114 | } |
| 115 | free(argv); |
| 116 | } |
| 117 | |
| 118 | return nullptr; |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Alloc an array of string pointer from an array of strings. It also adds |
| 123 | * the trace path to the argv. |
| 124 | * |
| 125 | * The returning pointer is ready to be passed to execvp(). |
| 126 | */ |
| 127 | static char **alloc_argv_from_local_opts(const char **opts, |
| 128 | size_t opts_len, |
| 129 | const char *trace_path, |
| 130 | bool opt_live_mode) |
| 131 | { |
| 132 | char **argv; |
| 133 | size_t mem_len; |
| 134 | |
| 135 | /* Add one for the NULL terminating element. */ |
| 136 | mem_len = opts_len + 1; |
| 137 | if (opt_live_mode) { |
| 138 | /* Add 3 option for the live mode being "-i lttng-live URL". */ |
| 139 | mem_len += 3; |
| 140 | } else { |
| 141 | /* Add option for the trace path. */ |
| 142 | mem_len += 1; |
| 143 | } |
| 144 | |
| 145 | argv = calloc<char *>(mem_len); |
| 146 | if (argv == nullptr) { |
| 147 | goto error; |
| 148 | } |
| 149 | |
| 150 | memcpy(argv, opts, sizeof(char *) * opts_len); |
| 151 | |
| 152 | if (opt_live_mode) { |
| 153 | argv[opts_len] = (char *) "-i"; |
| 154 | argv[opts_len + 1] = (char *) "lttng-live"; |
| 155 | argv[opts_len + 2] = (char *) trace_path; |
| 156 | argv[opts_len + 3] = nullptr; |
| 157 | } else { |
| 158 | argv[opts_len] = (char *) trace_path; |
| 159 | argv[opts_len + 1] = nullptr; |
| 160 | } |
| 161 | |
| 162 | error: |
| 163 | return argv; |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * Spawn viewer with the trace directory path. |
| 168 | */ |
| 169 | int spawn_viewer(const char *trace_path, char *opt_viewer, bool opt_live_mode) |
| 170 | { |
| 171 | int ret = 0; |
| 172 | struct stat status; |
| 173 | const char *viewer_bin = nullptr; |
| 174 | const struct viewer *viewer; |
| 175 | char **argv = nullptr; |
| 176 | |
| 177 | /* Check for --viewer option. */ |
| 178 | viewer = parse_viewer_option(opt_viewer); |
| 179 | if (viewer == nullptr) { |
| 180 | ret = -1; |
| 181 | goto error; |
| 182 | } |
| 183 | |
| 184 | retry_viewer: |
| 185 | switch (viewer->type) { |
| 186 | case VIEWER_BABELTRACE2: |
| 187 | if (stat(babeltrace2_bin, &status) == 0) { |
| 188 | viewer_bin = babeltrace2_bin; |
| 189 | } else { |
| 190 | viewer_bin = viewer->exec_name; |
| 191 | } |
| 192 | argv = alloc_argv_from_local_opts( |
| 193 | babeltrace2_opts, ARRAY_SIZE(babeltrace2_opts), trace_path, opt_live_mode); |
| 194 | break; |
| 195 | case VIEWER_BABELTRACE: |
| 196 | if (stat(babeltrace_bin, &status) == 0) { |
| 197 | viewer_bin = babeltrace_bin; |
| 198 | } else { |
| 199 | viewer_bin = viewer->exec_name; |
| 200 | } |
| 201 | argv = alloc_argv_from_local_opts( |
| 202 | babeltrace_opts, ARRAY_SIZE(babeltrace_opts), trace_path, opt_live_mode); |
| 203 | break; |
| 204 | case VIEWER_USER_DEFINED: |
| 205 | argv = alloc_argv_from_user_opts(opt_viewer, trace_path); |
| 206 | if (argv) { |
| 207 | viewer_bin = argv[0]; |
| 208 | } |
| 209 | break; |
| 210 | default: |
| 211 | abort(); |
| 212 | } |
| 213 | |
| 214 | if (argv == nullptr || !viewer_bin) { |
| 215 | ret = -1; |
| 216 | goto error; |
| 217 | } |
| 218 | |
| 219 | DBG("Using %s viewer", viewer_bin); |
| 220 | |
| 221 | ret = execvp(viewer_bin, argv); |
| 222 | if (ret) { |
| 223 | if (errno == ENOENT && viewer->exec_name) { |
| 224 | if (viewer->type == VIEWER_BABELTRACE2) { |
| 225 | /* Fallback to legacy babeltrace. */ |
| 226 | DBG("Default viewer \"%s\" not installed on the system, falling back to \"%s\"", |
| 227 | viewers[VIEWER_BABELTRACE2].exec_name, |
| 228 | viewers[VIEWER_BABELTRACE].exec_name); |
| 229 | viewer = &viewers[VIEWER_BABELTRACE]; |
| 230 | free(argv); |
| 231 | argv = nullptr; |
| 232 | goto retry_viewer; |
| 233 | } else { |
| 234 | ERR("Default viewer \"%s\" (and fallback \"%s\") not found on the system", |
| 235 | viewers[VIEWER_BABELTRACE2].exec_name, |
| 236 | viewers[VIEWER_BABELTRACE].exec_name); |
| 237 | } |
| 238 | } else { |
| 239 | PERROR("Failed to launch \"%s\" viewer", viewer_bin); |
| 240 | } |
| 241 | ret = -1; |
| 242 | goto error; |
| 243 | } |
| 244 | |
| 245 | /* |
| 246 | * This function should never return if successfull because `execvp(3)` |
| 247 | * onle returns if an error has occurred. |
| 248 | */ |
| 249 | LTTNG_ASSERT(ret != 0); |
| 250 | error: |
| 251 | free(argv); |
| 252 | return ret; |
| 253 | } |