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dd392e94 FD |
1 | /* |
2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
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: GPL-2.0-only | |
7 | * | |
8 | */ | |
9 | ||
10 | #include <assert.h> | |
11 | #include <stdbool.h> | |
12 | #include <sys/stat.h> | |
13 | #include <sys/types.h> | |
14 | #include <unistd.h> | |
dd392e94 FD |
15 | |
16 | #include <lttng/constant.h> | |
17 | ||
edf4b93e | 18 | #include <common/compat/errno.h> |
dd392e94 FD |
19 | #include "error.h" |
20 | #include "macros.h" | |
21 | #include "spawn-viewer.h" | |
22 | ||
23 | ||
24 | static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN; | |
25 | static const char *babeltrace2_bin = CONFIG_BABELTRACE2_BIN; | |
26 | ||
27 | /* | |
28 | * This is needed for each viewer since we are using execvp(). | |
29 | */ | |
30 | static const char *babeltrace_opts[] = { "babeltrace" }; | |
31 | static const char *babeltrace2_opts[] = { "babeltrace2" }; | |
32 | ||
33 | /* | |
34 | * Type is also use as the index in the viewers array. So please, make sure | |
35 | * your enum value is in the right order in the array below. | |
36 | */ | |
37 | enum viewer_type { | |
38 | VIEWER_BABELTRACE = 0, | |
39 | VIEWER_BABELTRACE2 = 1, | |
40 | VIEWER_USER_DEFINED = 2, | |
41 | }; | |
42 | ||
43 | static const struct viewer { | |
44 | const char *exec_name; | |
45 | enum viewer_type type; | |
46 | } viewers[] = { | |
47 | { "babeltrace", VIEWER_BABELTRACE }, | |
48 | { "babeltrace2", VIEWER_BABELTRACE2 }, | |
49 | { NULL, VIEWER_USER_DEFINED }, | |
50 | }; | |
51 | ||
52 | static const struct viewer *parse_viewer_option(const char *opt_viewer) | |
53 | { | |
54 | if (opt_viewer == NULL) { | |
55 | /* Default is babeltrace2 */ | |
56 | return &(viewers[VIEWER_BABELTRACE2]); | |
57 | } | |
58 | ||
59 | return &(viewers[VIEWER_USER_DEFINED]); | |
60 | } | |
61 | ||
62 | /* | |
63 | * Alloc an array of string pointer from a simple string having all options | |
64 | * seperated by spaces. Also adds the trace path to the arguments. | |
65 | * | |
66 | * The returning pointer is ready to be passed to execvp(). | |
67 | */ | |
68 | static char **alloc_argv_from_user_opts(char *opts, const char *trace_path) | |
69 | { | |
70 | int i = 0, ignore_space = 0; | |
71 | unsigned int num_opts = 1; | |
a825ed8c | 72 | char **argv, *token = opts, *saveptr = NULL; |
dd392e94 FD |
73 | |
74 | /* Count number of arguments. */ | |
75 | do { | |
76 | if (*token == ' ') { | |
77 | /* Use to ignore consecutive spaces */ | |
78 | if (!ignore_space) { | |
79 | num_opts++; | |
80 | } | |
81 | ignore_space = 1; | |
82 | } else { | |
83 | ignore_space = 0; | |
84 | } | |
85 | token++; | |
86 | } while (*token != '\0'); | |
87 | ||
88 | /* Add two here for the NULL terminating element and trace path */ | |
89 | argv = zmalloc(sizeof(char *) * (num_opts + 2)); | |
90 | if (argv == NULL) { | |
91 | goto error; | |
92 | } | |
93 | ||
77368158 | 94 | token = strtok_r(opts, " ", &saveptr); |
dd392e94 FD |
95 | while (token != NULL) { |
96 | argv[i] = strdup(token); | |
97 | if (argv[i] == NULL) { | |
98 | goto error; | |
99 | } | |
77368158 | 100 | token = strtok_r(NULL, " ", &saveptr); |
dd392e94 FD |
101 | i++; |
102 | } | |
103 | ||
104 | argv[num_opts] = (char *) trace_path; | |
105 | argv[num_opts + 1] = NULL; | |
106 | ||
107 | return argv; | |
108 | ||
109 | error: | |
110 | if (argv) { | |
111 | for (i = 0; i < num_opts + 2; i++) { | |
112 | free(argv[i]); | |
113 | } | |
114 | free(argv); | |
115 | } | |
116 | ||
117 | return NULL; | |
118 | } | |
119 | ||
120 | /* | |
121 | * Alloc an array of string pointer from an array of strings. It also adds | |
122 | * the trace path to the argv. | |
123 | * | |
124 | * The returning pointer is ready to be passed to execvp(). | |
125 | */ | |
126 | static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len, | |
127 | const char *trace_path, bool opt_live_mode) | |
128 | { | |
129 | char **argv; | |
130 | size_t size, mem_len; | |
131 | ||
132 | /* Add one for the NULL terminating element. */ | |
133 | mem_len = opts_len + 1; | |
134 | if (opt_live_mode) { | |
135 | /* Add 3 option for the live mode being "-i lttng-live URL". */ | |
136 | mem_len += 3; | |
137 | } else { | |
138 | /* Add option for the trace path. */ | |
139 | mem_len += 1; | |
140 | } | |
141 | ||
142 | size = sizeof(char *) * mem_len; | |
143 | ||
144 | /* Add two here for the trace_path and the NULL terminating element. */ | |
145 | argv = zmalloc(size); | |
146 | if (argv == NULL) { | |
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] = NULL; | |
157 | } else { | |
158 | argv[opts_len] = (char *) trace_path; | |
159 | argv[opts_len + 1] = NULL; | |
160 | } | |
161 | ||
162 | error: | |
163 | return argv; | |
164 | } | |
165 | ||
166 | ||
167 | /* | |
168 | * Spawn viewer with the trace directory path. | |
169 | */ | |
170 | int spawn_viewer(const char *trace_path, char *opt_viewer, bool opt_live_mode) | |
171 | { | |
172 | int ret = 0; | |
173 | struct stat status; | |
174 | const char *viewer_bin = NULL; | |
175 | const struct viewer *viewer; | |
176 | char **argv = NULL; | |
177 | ||
178 | /* Check for --viewer option. */ | |
179 | viewer = parse_viewer_option(opt_viewer); | |
180 | if (viewer == NULL) { | |
181 | ret = -1; | |
182 | goto error; | |
183 | } | |
184 | ||
185 | retry_viewer: | |
186 | switch (viewer->type) { | |
187 | case VIEWER_BABELTRACE2: | |
188 | if (stat(babeltrace2_bin, &status) == 0) { | |
189 | viewer_bin = babeltrace2_bin; | |
190 | } else { | |
191 | viewer_bin = viewer->exec_name; | |
192 | } | |
193 | argv = alloc_argv_from_local_opts(babeltrace2_opts, | |
194 | ARRAY_SIZE(babeltrace2_opts), trace_path, | |
195 | opt_live_mode); | |
196 | break; | |
197 | case VIEWER_BABELTRACE: | |
198 | if (stat(babeltrace_bin, &status) == 0) { | |
199 | viewer_bin = babeltrace_bin; | |
200 | } else { | |
201 | viewer_bin = viewer->exec_name; | |
202 | } | |
203 | argv = alloc_argv_from_local_opts(babeltrace_opts, | |
204 | ARRAY_SIZE(babeltrace_opts), trace_path, | |
205 | opt_live_mode); | |
206 | break; | |
207 | case VIEWER_USER_DEFINED: | |
208 | argv = alloc_argv_from_user_opts(opt_viewer, trace_path); | |
209 | if (argv) { | |
210 | viewer_bin = argv[0]; | |
211 | } | |
212 | break; | |
213 | default: | |
214 | abort(); | |
215 | } | |
216 | ||
217 | if (argv == NULL || !viewer_bin) { | |
218 | ret = -1; | |
219 | goto error; | |
220 | } | |
221 | ||
222 | DBG("Using %s viewer", viewer_bin); | |
223 | ||
224 | ret = execvp(viewer_bin, argv); | |
225 | if (ret) { | |
226 | if (errno == ENOENT && viewer->exec_name) { | |
227 | if (viewer->type == VIEWER_BABELTRACE2) { | |
228 | /* Fallback to legacy babeltrace. */ | |
229 | DBG("Default viewer \"%s\" not installed on the system, falling back to \"%s\"", | |
230 | viewers[VIEWER_BABELTRACE2].exec_name, | |
231 | viewers[VIEWER_BABELTRACE].exec_name); | |
232 | viewer = &viewers[VIEWER_BABELTRACE]; | |
233 | free(argv); | |
234 | argv = NULL; | |
235 | goto retry_viewer; | |
236 | } else { | |
237 | ERR("Default viewer \"%s\" (and fallback \"%s\") not found on the system", | |
238 | viewers[VIEWER_BABELTRACE2].exec_name, | |
239 | viewers[VIEWER_BABELTRACE].exec_name); | |
240 | } | |
241 | } else { | |
242 | PERROR("Failed to launch \"%s\" viewer", viewer_bin); | |
243 | } | |
244 | ret = -1; | |
245 | goto error; | |
246 | } | |
247 | ||
248 | /* | |
249 | * This function should never return if successfull because `execvp(3)` | |
250 | * onle returns if an error has occurred. | |
251 | */ | |
252 | assert(ret != 0); | |
253 | error: | |
254 | free(argv); | |
255 | return ret; | |
256 | } |