resolved: read the system /etc/resolv.conf unless we wrote it ourselves

[elogind.git] / src / shared / util.c

diff --git a/src/shared/util.c b/src/shared/util.c
index b1689e651f70fe570ec1eccf5706135905ec6b20..e2c955bc0700594620a7c517d2a368c7593f296e 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -140,26 +140,38 @@ char* endswith(const char *s, const char *postfix) {
         return (char*) s + sl - pl;
 }
 
-bool first_word(const char *s, const char *word) {
+char* first_word(const char *s, const char *word) {
         size_t sl, wl;
+        const char *p;
 
         assert(s);
         assert(word);
 
+        /* Checks if the string starts with the specified word, either
+         * followed by NUL or by whitespace. Returns a pointer to the
+         * NUL or the first character after the whitespace. */
+
         sl = strlen(s);
         wl = strlen(word);
 
         if (sl < wl)
-                return false;
+                return NULL;
 
         if (wl == 0)
-                return true;
+                return (char*) s;
 
         if (memcmp(s, word, wl) != 0)
-                return false;
+                return NULL;
+
+        p = s + wl;
+        if (*p == 0)
+                return (char*) p;
+
+        if (!strchr(WHITESPACE, *p))
+                return NULL;
 
-        return s[wl] == 0 ||
-                strchr(WHITESPACE, s[wl]);
+        p += strspn(p, WHITESPACE);
+        return (char*) p;
 }
 
 int close_nointr(int fd) {
@@ -332,6 +344,26 @@ int safe_atoi(const char *s, int *ret_i) {
         return 0;
 }
 
+int safe_atou8(const char *s, uint8_t *ret) {
+        char *x = NULL;
+        unsigned long l;
+
+        assert(s);
+        assert(ret);
+
+        errno = 0;
+        l = strtoul(s, &x, 0);
+
+        if (!x || x == s || *x || errno)
+                return errno > 0 ? -errno : -EINVAL;
+
+        if ((unsigned long) (uint8_t) l != l)
+                return -ERANGE;
+
+        *ret = (uint8_t) l;
+        return 0;
+}
+
 int safe_atollu(const char *s, long long unsigned *ret_llu) {
         char *x = NULL;
         unsigned long long l;
@@ -395,37 +427,50 @@ static size_t strcspn_escaped(const char *s, const char *reject) {
                 else if (s[n] == '\\')
                         escaped = true;
                 else if (strchr(reject, s[n]))
-                        return n;
+                        break;
         }
-        return n;
+        /* if s ends in \, return index of previous char */
+        return n - escaped;
 }
 
 /* Split a string into words. */
-char *split(const char *c, size_t *l, const char *separator, bool quoted, char **state) {
-        char *current;
+const char* split(const char **state, size_t *l, const char *separator, bool quoted) {
+        const char *current;
 
-        current = *state ? *state : (char*) c;
+        current = *state;
 
-        if (!*current || *c == 0)
+        if (!*current) {
+                assert(**state == '\0');
                 return NULL;
+        }
 
         current += strspn(current, separator);
-        if (!*current)
+        if (!*current) {
+                *state = current;
                 return NULL;
+        }
 
         if (quoted && strchr("\'\"", *current)) {
-                char quotechar = *(current++);
-                *l = strcspn_escaped(current, (char[]){quotechar, '\0'});
-                *state = current+*l+1;
+                char quotechars[2] = {*current, '\0'};
+
+                *l = strcspn_escaped(current + 1, quotechars);
+                if (current[*l + 1] == '\0' ||
+                    (current[*l + 2] && !strchr(separator, current[*l + 2]))) {
+                        /* right quote missing or garbage at the end*/
+                        *state = current;
+                        return NULL;
+                }
+                assert(current[*l + 1] == quotechars[0]);
+                *state = current++ + *l + 2;
         } else if (quoted) {
                 *l = strcspn_escaped(current, separator);
-                *state = current+*l;
+                *state = current + *l;
         } else {
                 *l = strcspn(current, separator);
-                *state = current+*l;
+                *state = current + *l;
         }
 
-        return (char*) current;
+        return current;
 }
 
 int get_parent_of_pid(pid_t pid, pid_t *_ppid) {
@@ -1197,7 +1242,7 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre
 
         r = new(char, pl+length+1);
         if (!r)
-                return r;
+                return NULL;
 
         if (prefix)
                 memcpy(r, prefix, pl);
@@ -3130,12 +3175,13 @@ fail:
 }
 
 char **replace_env_argv(char **argv, char **env) {
-        char **r, **i;
+        char **ret, **i;
         unsigned k = 0, l = 0;
 
         l = strv_length(argv);
 
-        if (!(r = new(char*, l+1)))
+        ret = new(char*, l+1);
+        if (!ret)
                 return NULL;
 
         STRV_FOREACH(i, argv) {
@@ -3148,10 +3194,12 @@ char **replace_env_argv(char **argv, char **env) {
 
                         e = strv_env_get(env, *i+1);
                         if (e) {
+                                int r;
 
-                                if (!(m = strv_split_quoted(e))) {
-                                        r[k] = NULL;
-                                        strv_free(r);
+                                r = strv_split_quoted(&m, e);
+                                if (r < 0) {
+                                        ret[k] = NULL;
+                                        strv_free(ret);
                                         return NULL;
                                 }
                         } else
@@ -3160,16 +3208,17 @@ char **replace_env_argv(char **argv, char **env) {
                         q = strv_length(m);
                         l = l + q - 1;
 
-                        if (!(w = realloc(r, sizeof(char*) * (l+1)))) {
-                                r[k] = NULL;
-                                strv_free(r);
+                        w = realloc(ret, sizeof(char*) * (l+1));
+                        if (!w) {
+                                ret[k] = NULL;
+                                strv_free(ret);
                                 strv_free(m);
                                 return NULL;
                         }
 
-                        r = w;
+                        ret = w;
                         if (m) {
-                                memcpy(r + k, m, q * sizeof(char*));
+                                memcpy(ret + k, m, q * sizeof(char*));
                                 free(m);
                         }
 
@@ -3178,14 +3227,16 @@ char **replace_env_argv(char **argv, char **env) {
                 }
 
                 /* If ${FOO} appears as part of a word, replace it by the variable as-is */
-                if (!(r[k++] = replace_env(*i, env))) {
-                        strv_free(r);
+                ret[k] = replace_env(*i, env);
+                if (!ret[k]) {
+                        strv_free(ret);
                         return NULL;
                 }
+                k++;
         }
 
-        r[k] = NULL;
-        return r;
+        ret[k] = NULL;
+        return ret;
 }
 
 int fd_columns(int fd) {
@@ -6039,7 +6090,7 @@ int split_pair(const char *s, const char *sep, char **l, char **r) {
 
 int shall_restore_state(void) {
         _cleanup_free_ char *line = NULL;
-        char *w, *state;
+        const char *word, *state;
         size_t l;
         int r;
 
@@ -6051,12 +6102,12 @@ int shall_restore_state(void) {
 
         r = 1;
 
-        FOREACH_WORD_QUOTED(w, l, line, state) {
+        FOREACH_WORD_QUOTED(word, l, line, state) {
                 const char *e;
                 char n[l+1];
                 int k;
 
-                memcpy(n, w, l);
+                memcpy(n, word, l);
                 n[l] = 0;
 
                 e = startswith(n, "systemd.restore_state=");
@@ -6100,7 +6151,7 @@ int proc_cmdline(char **ret) {
 
 int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value)) {
         _cleanup_free_ char *line = NULL;
-        char *w, *state;
+        const char *w, *state;
         size_t l;
         int r;