Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2f4ce5ec JP |
2 | #include <linux/compiler.h> |
3 | #include <linux/string.h> | |
4 | #include <sys/types.h> | |
5 | #include <sys/stat.h> | |
6 | #include <unistd.h> | |
f37a291c | 7 | #include <string.h> |
2f4ce5ec JP |
8 | #include <stdlib.h> |
9 | #include <stdio.h> | |
901421a5 | 10 | #include "subcmd-util.h" |
4b6ab94e | 11 | #include "exec-cmd.h" |
2f4ce5ec | 12 | #include "subcmd-config.h" |
f37a291c | 13 | |
07800601 | 14 | #define MAX_ARGS 32 |
2f4ce5ec | 15 | #define PATH_MAX 4096 |
07800601 | 16 | |
07800601 IM |
17 | static const char *argv_exec_path; |
18 | static const char *argv0_path; | |
19 | ||
096d3558 JP |
20 | void exec_cmd_init(const char *exec_name, const char *prefix, |
21 | const char *exec_path, const char *exec_path_env) | |
22 | { | |
23 | subcmd_config.exec_name = exec_name; | |
24 | subcmd_config.prefix = prefix; | |
25 | subcmd_config.exec_path = exec_path; | |
26 | subcmd_config.exec_path_env = exec_path_env; | |
27 | } | |
28 | ||
2f4ce5ec JP |
29 | #define is_dir_sep(c) ((c) == '/') |
30 | ||
31 | static int is_absolute_path(const char *path) | |
32 | { | |
33 | return path[0] == '/'; | |
34 | } | |
35 | ||
36 | static const char *get_pwd_cwd(void) | |
37 | { | |
38 | static char cwd[PATH_MAX + 1]; | |
39 | char *pwd; | |
40 | struct stat cwd_stat, pwd_stat; | |
41 | if (getcwd(cwd, PATH_MAX) == NULL) | |
42 | return NULL; | |
43 | pwd = getenv("PWD"); | |
44 | if (pwd && strcmp(pwd, cwd)) { | |
45 | stat(cwd, &cwd_stat); | |
46 | if (!stat(pwd, &pwd_stat) && | |
47 | pwd_stat.st_dev == cwd_stat.st_dev && | |
48 | pwd_stat.st_ino == cwd_stat.st_ino) { | |
49 | strlcpy(cwd, pwd, PATH_MAX); | |
50 | } | |
51 | } | |
52 | return cwd; | |
53 | } | |
54 | ||
55 | static const char *make_nonrelative_path(const char *path) | |
56 | { | |
57 | static char buf[PATH_MAX + 1]; | |
58 | ||
59 | if (is_absolute_path(path)) { | |
60 | if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX) | |
61 | die("Too long path: %.*s", 60, path); | |
62 | } else { | |
63 | const char *cwd = get_pwd_cwd(); | |
64 | if (!cwd) | |
65 | die("Cannot determine the current working directory"); | |
66 | if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX) | |
67 | die("Too long path: %.*s", 60, path); | |
68 | } | |
69 | return buf; | |
70 | } | |
71 | ||
c4068f51 | 72 | char *system_path(const char *path) |
07800601 | 73 | { |
901421a5 | 74 | char *buf = NULL; |
07800601 IM |
75 | |
76 | if (is_absolute_path(path)) | |
c4068f51 | 77 | return strdup(path); |
07800601 | 78 | |
901421a5 JP |
79 | astrcatf(&buf, "%s/%s", subcmd_config.prefix, path); |
80 | ||
81 | return buf; | |
07800601 IM |
82 | } |
83 | ||
46113a54 | 84 | const char *extract_argv0_path(const char *argv0) |
07800601 IM |
85 | { |
86 | const char *slash; | |
87 | ||
88 | if (!argv0 || !*argv0) | |
89 | return NULL; | |
90 | slash = argv0 + strlen(argv0); | |
91 | ||
92 | while (argv0 <= slash && !is_dir_sep(*slash)) | |
93 | slash--; | |
94 | ||
95 | if (slash >= argv0) { | |
151f85a4 ACM |
96 | argv0_path = strndup(argv0, slash - argv0); |
97 | return argv0_path ? slash + 1 : NULL; | |
07800601 IM |
98 | } |
99 | ||
100 | return argv0; | |
101 | } | |
102 | ||
46113a54 | 103 | void set_argv_exec_path(const char *exec_path) |
07800601 IM |
104 | { |
105 | argv_exec_path = exec_path; | |
106 | /* | |
107 | * Propagate this setting to external programs. | |
108 | */ | |
096d3558 | 109 | setenv(subcmd_config.exec_path_env, exec_path, 1); |
07800601 IM |
110 | } |
111 | ||
112 | ||
46113a54 JP |
113 | /* Returns the highest-priority location to look for subprograms. */ |
114 | char *get_argv_exec_path(void) | |
07800601 | 115 | { |
c4068f51 | 116 | char *env; |
07800601 IM |
117 | |
118 | if (argv_exec_path) | |
c4068f51 | 119 | return strdup(argv_exec_path); |
07800601 | 120 | |
096d3558 | 121 | env = getenv(subcmd_config.exec_path_env); |
c4068f51 MH |
122 | if (env && *env) |
123 | return strdup(env); | |
07800601 | 124 | |
096d3558 | 125 | return system_path(subcmd_config.exec_path); |
07800601 IM |
126 | } |
127 | ||
901421a5 | 128 | static void add_path(char **out, const char *path) |
07800601 IM |
129 | { |
130 | if (path && *path) { | |
131 | if (is_absolute_path(path)) | |
901421a5 | 132 | astrcat(out, path); |
07800601 | 133 | else |
901421a5 | 134 | astrcat(out, make_nonrelative_path(path)); |
07800601 | 135 | |
901421a5 | 136 | astrcat(out, ":"); |
07800601 IM |
137 | } |
138 | } | |
139 | ||
140 | void setup_path(void) | |
141 | { | |
142 | const char *old_path = getenv("PATH"); | |
901421a5 | 143 | char *new_path = NULL; |
46113a54 | 144 | char *tmp = get_argv_exec_path(); |
07800601 | 145 | |
c4068f51 | 146 | add_path(&new_path, tmp); |
07800601 | 147 | add_path(&new_path, argv0_path); |
c4068f51 | 148 | free(tmp); |
07800601 IM |
149 | |
150 | if (old_path) | |
901421a5 | 151 | astrcat(&new_path, old_path); |
07800601 | 152 | else |
901421a5 | 153 | astrcat(&new_path, "/usr/local/bin:/usr/bin:/bin"); |
07800601 | 154 | |
901421a5 | 155 | setenv("PATH", new_path, 1); |
07800601 | 156 | |
901421a5 | 157 | free(new_path); |
07800601 IM |
158 | } |
159 | ||
46113a54 | 160 | static const char **prepare_exec_cmd(const char **argv) |
07800601 IM |
161 | { |
162 | int argc; | |
163 | const char **nargv; | |
164 | ||
165 | for (argc = 0; argv[argc]; argc++) | |
166 | ; /* just counting */ | |
167 | nargv = malloc(sizeof(*nargv) * (argc + 2)); | |
168 | ||
096d3558 | 169 | nargv[0] = subcmd_config.exec_name; |
07800601 IM |
170 | for (argc = 0; argv[argc]; argc++) |
171 | nargv[argc + 1] = argv[argc]; | |
172 | nargv[argc + 1] = NULL; | |
173 | return nargv; | |
174 | } | |
175 | ||
46113a54 JP |
176 | int execv_cmd(const char **argv) { |
177 | const char **nargv = prepare_exec_cmd(argv); | |
07800601 IM |
178 | |
179 | /* execvp() can only ever return if it fails */ | |
096d3558 | 180 | execvp(subcmd_config.exec_name, (char **)nargv); |
07800601 IM |
181 | |
182 | free(nargv); | |
183 | return -1; | |
184 | } | |
185 | ||
186 | ||
46113a54 | 187 | int execl_cmd(const char *cmd,...) |
07800601 IM |
188 | { |
189 | int argc; | |
190 | const char *argv[MAX_ARGS + 1]; | |
191 | const char *arg; | |
192 | va_list param; | |
193 | ||
194 | va_start(param, cmd); | |
195 | argv[0] = cmd; | |
196 | argc = 1; | |
197 | while (argc < MAX_ARGS) { | |
198 | arg = argv[argc++] = va_arg(param, char *); | |
199 | if (!arg) | |
200 | break; | |
201 | } | |
202 | va_end(param); | |
2f4ce5ec JP |
203 | if (MAX_ARGS <= argc) { |
204 | fprintf(stderr, " Error: too many args to run %s\n", cmd); | |
205 | return -1; | |
206 | } | |
07800601 IM |
207 | |
208 | argv[argc] = NULL; | |
46113a54 | 209 | return execv_cmd(argv); |
07800601 | 210 | } |