execute: support minimal environment variable replacement when executing processes

This commit is contained in:
Lennart Poettering 2010-07-08 04:09:59 +02:00
parent 1e3ad081ef
commit fab56fc541
5 changed files with 141 additions and 5 deletions

View File

@ -943,7 +943,7 @@ int exec_spawn(ExecCommand *command,
const char *username = NULL, *home = NULL;
uid_t uid = (uid_t) -1;
gid_t gid = (gid_t) -1;
char **our_env = NULL, **pam_env = NULL, **final_env = NULL;
char **our_env = NULL, **pam_env = NULL, **final_env = NULL, **final_argv = NULL;
unsigned n_env = 0;
int saved_stdout = -1, saved_stdin = -1;
bool keep_stdout = false, keep_stdin = false;
@ -1260,13 +1260,19 @@ int exec_spawn(ExecCommand *command,
goto fail;
}
execve(command->path, argv, final_env);
if (!(final_argv = replace_env_argv(argv, final_env))) {
r = EXIT_MEMORY;
goto fail;
}
execve(command->path, final_argv, final_env);
r = EXIT_EXEC;
fail:
strv_free(our_env);
strv_free(final_env);
strv_free(pam_env);
strv_free(final_argv);
if (saved_stdin >= 0)
close_nointr_nofail(saved_stdin);

View File

@ -539,3 +539,20 @@ fail:
return NULL;
}
char *strv_env_get_with_length(char **l, const char *name, size_t k) {
char **i;
assert(name);
STRV_FOREACH(i, l)
if (strncmp(*i, name, k) == 0 &&
(*i)[k] == '=')
return *i + k + 1;
return NULL;
}
char *strv_env_get(char **l, const char *name) {
return strv_env_get_with_length(l, name, strlen(name));
}

View File

@ -60,6 +60,9 @@ char **strv_env_delete(char **x, unsigned n_lists, ...);
char **strv_env_set(char **x, const char *p);
char *strv_env_get_with_length(char **l, const char *name, size_t k);
char *strv_env_get(char **x, const char *n);
#define STRV_FOREACH(s, l) \
for ((s) = (l); (s) && *(s); (s)++)

View File

@ -613,15 +613,23 @@ int get_process_cmdline(pid_t pid, size_t max_length, char **line) {
return 0;
}
char *strappend(const char *s, const char *suffix) {
size_t a, b;
char *strnappend(const char *s, const char *suffix, size_t b) {
size_t a;
char *r;
if (!s && !suffix)
return strdup("");
if (!s)
return strndup(suffix, b);
if (!suffix)
return strdup(s);
assert(s);
assert(suffix);
a = strlen(s);
b = strlen(suffix);
if (!(r = new(char, a+b+1)))
return NULL;
@ -633,6 +641,10 @@ char *strappend(const char *s, const char *suffix) {
return r;
}
char *strappend(const char *s, const char *suffix) {
return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
}
int readlink_malloc(const char *p, char **r) {
size_t l = 100;
@ -2692,6 +2704,100 @@ void status_welcome(void) {
#endif
}
char *replace_env(const char *format, char **env) {
enum {
WORD,
DOLLAR,
VARIABLE
} state = WORD;
const char *e, *word = format;
char *r = NULL, *k;
assert(format);
for (e = format; *e; e ++) {
switch (state) {
case WORD:
if (*e == '$')
state = DOLLAR;
break;
case DOLLAR:
if (*e == '(') {
if (!(k = strnappend(r, word, e-word-1)))
goto fail;
free(r);
r = k;
word = e-1;
state = VARIABLE;
} else if (*e == '$') {
if (!(k = strnappend(r, word, e-word)))
goto fail;
free(r);
r = k;
word = e+1;
state = WORD;
} else
state = WORD;
break;
case VARIABLE:
if (*e == ')') {
char *t;
if ((t = strv_env_get_with_length(env, word+2, e-word-2))) {
if (!(k = strappend(r, t)))
goto fail;
free(r);
r = k;
word = e+1;
}
state = WORD;
}
break;
}
}
if (!(k = strnappend(r, word, e-word)))
goto fail;
free(r);
return k;
fail:
free(r);
return NULL;
}
char **replace_env_argv(char **argv, char **env) {
char **r, **i;
unsigned k;
if (!(r = new(char*, strv_length(argv)+1)))
return NULL;
STRV_FOREACH(i, argv) {
if (!(r[k++] = replace_env(*i, env))) {
strv_free(r);
return NULL;
}
}
r[k] = NULL;
return r;
}
static const char *const ioprio_class_table[] = {
[IOPRIO_CLASS_NONE] = "none",
[IOPRIO_CLASS_RT] = "realtime",

View File

@ -183,6 +183,10 @@ int write_one_line_file(const char *fn, const char *line);
int read_one_line_file(const char *fn, char **line);
char *strappend(const char *s, const char *suffix);
char *strnappend(const char *s, const char *suffix, size_t length);
char *replace_env(const char *format, char **env);
char **replace_env_argv(char **argv, char **env);
int readlink_malloc(const char *p, char **r);
int readlink_and_make_absolute(const char *p, char **r);