1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/compiler.h> 2 #include <linux/compiler.h>
3 #include <linux/string.h> 3 #include <linux/string.h>
4 #include <sys/types.h> 4 #include <sys/types.h>
5 #include <sys/stat.h> 5 #include <sys/stat.h>
6 #include <unistd.h> 6 #include <unistd.h>
7 #include <string.h> 7 #include <string.h>
8 #include <stdlib.h> 8 #include <stdlib.h>
9 #include <stdio.h> 9 #include <stdio.h>
10 #include "subcmd-util.h" 10 #include "subcmd-util.h"
11 #include "exec-cmd.h" 11 #include "exec-cmd.h"
12 #include "subcmd-config.h" 12 #include "subcmd-config.h"
13 13
14 #define MAX_ARGS 32 14 #define MAX_ARGS 32
15 #define PATH_MAX 4096 15 #define PATH_MAX 4096
16 16
17 static const char *argv_exec_path; 17 static const char *argv_exec_path;
18 static const char *argv0_path; 18 static const char *argv0_path;
19 19
20 void exec_cmd_init(const char *exec_name, cons 20 void exec_cmd_init(const char *exec_name, const char *prefix,
21 const char *exec_path, cons 21 const char *exec_path, const char *exec_path_env)
22 { 22 {
23 subcmd_config.exec_name = exec 23 subcmd_config.exec_name = exec_name;
24 subcmd_config.prefix = pref 24 subcmd_config.prefix = prefix;
25 subcmd_config.exec_path = exec 25 subcmd_config.exec_path = exec_path;
26 subcmd_config.exec_path_env = exec 26 subcmd_config.exec_path_env = exec_path_env;
27 27
28 /* Setup environment variable for invo 28 /* Setup environment variable for invoked shell script. */
29 setenv("PREFIX", prefix, 1); 29 setenv("PREFIX", prefix, 1);
30 } 30 }
31 31
32 #define is_dir_sep(c) ((c) == '/') 32 #define is_dir_sep(c) ((c) == '/')
33 33
34 static int is_absolute_path(const char *path) 34 static int is_absolute_path(const char *path)
35 { 35 {
36 return path[0] == '/'; 36 return path[0] == '/';
37 } 37 }
38 38
39 static const char *get_pwd_cwd(char *buf, size 39 static const char *get_pwd_cwd(char *buf, size_t sz)
40 { 40 {
41 char *pwd; 41 char *pwd;
42 struct stat cwd_stat, pwd_stat; 42 struct stat cwd_stat, pwd_stat;
43 if (getcwd(buf, sz) == NULL) 43 if (getcwd(buf, sz) == NULL)
44 return NULL; 44 return NULL;
45 pwd = getenv("PWD"); 45 pwd = getenv("PWD");
46 if (pwd && strcmp(pwd, buf)) { 46 if (pwd && strcmp(pwd, buf)) {
47 stat(buf, &cwd_stat); 47 stat(buf, &cwd_stat);
48 if (!stat(pwd, &pwd_stat) && 48 if (!stat(pwd, &pwd_stat) &&
49 pwd_stat.st_dev == cwd_sta 49 pwd_stat.st_dev == cwd_stat.st_dev &&
50 pwd_stat.st_ino == cwd_sta 50 pwd_stat.st_ino == cwd_stat.st_ino) {
51 strlcpy(buf, pwd, sz); 51 strlcpy(buf, pwd, sz);
52 } 52 }
53 } 53 }
54 return buf; 54 return buf;
55 } 55 }
56 56
57 static const char *make_nonrelative_path(char 57 static const char *make_nonrelative_path(char *buf, size_t sz, const char *path)
58 { 58 {
59 if (is_absolute_path(path)) { 59 if (is_absolute_path(path)) {
60 if (strlcpy(buf, path, sz) >= 60 if (strlcpy(buf, path, sz) >= sz)
61 die("Too long path: %. 61 die("Too long path: %.*s", 60, path);
62 } else { 62 } else {
63 const char *cwd = get_pwd_cwd( 63 const char *cwd = get_pwd_cwd(buf, sz);
64 64
65 if (!cwd) 65 if (!cwd)
66 die("Cannot determine 66 die("Cannot determine the current working directory");
67 67
68 if (strlen(cwd) + strlen(path) 68 if (strlen(cwd) + strlen(path) + 2 >= sz)
69 die("Too long path: %. 69 die("Too long path: %.*s", 60, path);
70 70
71 strcat(buf, "/"); 71 strcat(buf, "/");
72 strcat(buf, path); 72 strcat(buf, path);
73 } 73 }
74 return buf; 74 return buf;
75 } 75 }
76 76
77 char *system_path(const char *path) 77 char *system_path(const char *path)
78 { 78 {
79 char *buf = NULL; 79 char *buf = NULL;
80 80
81 if (is_absolute_path(path)) 81 if (is_absolute_path(path))
82 return strdup(path); 82 return strdup(path);
83 83
84 astrcatf(&buf, "%s/%s", subcmd_config. 84 astrcatf(&buf, "%s/%s", subcmd_config.prefix, path);
85 85
86 return buf; 86 return buf;
87 } 87 }
88 88
89 const char *extract_argv0_path(const char *arg 89 const char *extract_argv0_path(const char *argv0)
90 { 90 {
91 const char *slash; 91 const char *slash;
92 92
93 if (!argv0 || !*argv0) 93 if (!argv0 || !*argv0)
94 return NULL; 94 return NULL;
95 slash = argv0 + strlen(argv0); 95 slash = argv0 + strlen(argv0);
96 96
97 while (argv0 <= slash && !is_dir_sep(* 97 while (argv0 <= slash && !is_dir_sep(*slash))
98 slash--; 98 slash--;
99 99
100 if (slash >= argv0) { 100 if (slash >= argv0) {
101 argv0_path = strndup(argv0, sl 101 argv0_path = strndup(argv0, slash - argv0);
102 return argv0_path ? slash + 1 102 return argv0_path ? slash + 1 : NULL;
103 } 103 }
104 104
105 return argv0; 105 return argv0;
106 } 106 }
107 107
108 void set_argv_exec_path(const char *exec_path) 108 void set_argv_exec_path(const char *exec_path)
109 { 109 {
110 argv_exec_path = exec_path; 110 argv_exec_path = exec_path;
111 /* 111 /*
112 * Propagate this setting to external 112 * Propagate this setting to external programs.
113 */ 113 */
114 setenv(subcmd_config.exec_path_env, ex 114 setenv(subcmd_config.exec_path_env, exec_path, 1);
115 } 115 }
116 116
117 117
118 /* Returns the highest-priority location to lo 118 /* Returns the highest-priority location to look for subprograms. */
119 char *get_argv_exec_path(void) 119 char *get_argv_exec_path(void)
120 { 120 {
121 char *env; 121 char *env;
122 122
123 if (argv_exec_path) 123 if (argv_exec_path)
124 return strdup(argv_exec_path); 124 return strdup(argv_exec_path);
125 125
126 env = getenv(subcmd_config.exec_path_e 126 env = getenv(subcmd_config.exec_path_env);
127 if (env && *env) 127 if (env && *env)
128 return strdup(env); 128 return strdup(env);
129 129
130 return system_path(subcmd_config.exec_ 130 return system_path(subcmd_config.exec_path);
131 } 131 }
132 132
133 static void add_path(char **out, const char *p 133 static void add_path(char **out, const char *path)
134 { 134 {
135 if (path && *path) { 135 if (path && *path) {
136 if (is_absolute_path(path)) 136 if (is_absolute_path(path))
137 astrcat(out, path); 137 astrcat(out, path);
138 else { 138 else {
139 char buf[PATH_MAX]; 139 char buf[PATH_MAX];
140 140
141 astrcat(out, make_nonr 141 astrcat(out, make_nonrelative_path(buf, sizeof(buf), path));
142 } 142 }
143 143
144 astrcat(out, ":"); 144 astrcat(out, ":");
145 } 145 }
146 } 146 }
147 147
148 void setup_path(void) 148 void setup_path(void)
149 { 149 {
150 const char *old_path = getenv("PATH"); 150 const char *old_path = getenv("PATH");
151 char *new_path = NULL; 151 char *new_path = NULL;
152 char *tmp = get_argv_exec_path(); 152 char *tmp = get_argv_exec_path();
153 153
154 add_path(&new_path, tmp); 154 add_path(&new_path, tmp);
155 add_path(&new_path, argv0_path); 155 add_path(&new_path, argv0_path);
156 free(tmp); 156 free(tmp);
157 157
158 if (old_path) 158 if (old_path)
159 astrcat(&new_path, old_path); 159 astrcat(&new_path, old_path);
160 else 160 else
161 astrcat(&new_path, "/usr/local 161 astrcat(&new_path, "/usr/local/bin:/usr/bin:/bin");
162 162
163 setenv("PATH", new_path, 1); 163 setenv("PATH", new_path, 1);
164 164
165 free(new_path); 165 free(new_path);
166 } 166 }
167 167
168 static const char **prepare_exec_cmd(const cha 168 static const char **prepare_exec_cmd(const char **argv)
169 { 169 {
170 int argc; 170 int argc;
171 const char **nargv; 171 const char **nargv;
172 172
173 for (argc = 0; argv[argc]; argc++) 173 for (argc = 0; argv[argc]; argc++)
174 ; /* just counting */ 174 ; /* just counting */
175 nargv = malloc(sizeof(*nargv) * (argc 175 nargv = malloc(sizeof(*nargv) * (argc + 2));
176 176
177 nargv[0] = subcmd_config.exec_name; 177 nargv[0] = subcmd_config.exec_name;
178 for (argc = 0; argv[argc]; argc++) 178 for (argc = 0; argv[argc]; argc++)
179 nargv[argc + 1] = argv[argc]; 179 nargv[argc + 1] = argv[argc];
180 nargv[argc + 1] = NULL; 180 nargv[argc + 1] = NULL;
181 return nargv; 181 return nargv;
182 } 182 }
183 183
184 int execv_cmd(const char **argv) { 184 int execv_cmd(const char **argv) {
185 const char **nargv = prepare_exec_cmd( 185 const char **nargv = prepare_exec_cmd(argv);
186 186
187 /* execvp() can only ever return if it 187 /* execvp() can only ever return if it fails */
188 execvp(subcmd_config.exec_name, (char 188 execvp(subcmd_config.exec_name, (char **)nargv);
189 189
190 free(nargv); 190 free(nargv);
191 return -1; 191 return -1;
192 } 192 }
193 193
194 194
195 int execl_cmd(const char *cmd,...) 195 int execl_cmd(const char *cmd,...)
196 { 196 {
197 int argc; 197 int argc;
198 const char *argv[MAX_ARGS + 1]; 198 const char *argv[MAX_ARGS + 1];
199 const char *arg; 199 const char *arg;
200 va_list param; 200 va_list param;
201 201
202 va_start(param, cmd); 202 va_start(param, cmd);
203 argv[0] = cmd; 203 argv[0] = cmd;
204 argc = 1; 204 argc = 1;
205 while (argc < MAX_ARGS) { 205 while (argc < MAX_ARGS) {
206 arg = argv[argc++] = va_arg(pa 206 arg = argv[argc++] = va_arg(param, char *);
207 if (!arg) 207 if (!arg)
208 break; 208 break;
209 } 209 }
210 va_end(param); 210 va_end(param);
211 if (MAX_ARGS <= argc) { 211 if (MAX_ARGS <= argc) {
212 fprintf(stderr, " Error: too m 212 fprintf(stderr, " Error: too many args to run %s\n", cmd);
213 return -1; 213 return -1;
214 } 214 }
215 215
216 argv[argc] = NULL; 216 argv[argc] = NULL;
217 return execv_cmd(argv); 217 return execv_cmd(argv);
218 } 218 }
219 219
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