nspawn: properly validate machine names

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

diff --git a/src/shared/util.c b/src/shared/util.c
index ff8835b72ddf7944d150ad83ef1a8d7c2be65e1e..273552f62222ea579244ae1244e08b1a62d993f3 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -558,7 +558,7 @@ const char* split(const char **state, size_t *l, const char *separator, bool quo
                 *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*/
+                        /* right quote missing or garbage at the end */
                         *state = current;
                         return NULL;
                 }
@@ -1436,7 +1436,7 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre
                 }
 
                 case 0:
-                        /* premature end of string.*/
+                        /* premature end of string. */
                         *(t++) = '\\';
                         goto finish;
 
@@ -2292,13 +2292,15 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
         return n;
 }
 
-ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
+int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
         const uint8_t *p = buf;
         ssize_t n = 0;
 
         assert(fd >= 0);
         assert(buf);
 
+        errno = 0;
+
         while (nbytes > 0) {
                 ssize_t k;
 
@@ -2317,14 +2319,15 @@ ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
                 }
 
                 if (k <= 0)
-                        return n > 0 ? n : (k < 0 ? -errno : 0);
+                        /* We were not done yet, and a write error occured. */
+                        return errno ? -errno : -EIO;
 
                 p += k;
                 nbytes -= k;
                 n += k;
         }
 
-        return n;
+        return 0;
 }
 
 int parse_size(const char *t, off_t base, off_t *size) {
@@ -3659,7 +3662,7 @@ char *unquote(const char *s, const char* quotes) {
         /* This is rather stupid, simply removes the heading and
          * trailing quotes if there is one. Doesn't care about
          * escaping or anything. We should make this smarter one
-         * day...*/
+         * day... */
 
         l = strlen(s);
         if (l < 2)
@@ -4281,15 +4284,15 @@ int fd_wait_for_event(int fd, int event, usec_t t) {
 int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
         FILE *f;
         char *t;
-        int fd;
+        int r, fd;
 
         assert(path);
         assert(_f);
         assert(_temp_path);
 
-        t = tempfn_xxxxxx(path);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_xxxxxx(path, &t);
+        if (r < 0)
+                return r;
 
         fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC);
         if (fd < 0) {
@@ -4400,13 +4403,14 @@ int vt_disallocate(const char *name) {
 
 int symlink_atomic(const char *from, const char *to) {
         _cleanup_free_ char *t = NULL;
+        int r;
 
         assert(from);
         assert(to);
 
-        t = tempfn_random(to);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_random(to, &t);
+        if (r < 0)
+                return r;
 
         if (symlink(from, t) < 0)
                 return -errno;
@@ -4421,12 +4425,13 @@ int symlink_atomic(const char *from, const char *to) {
 
 int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
         _cleanup_free_ char *t = NULL;
+        int r;
 
         assert(path);
 
-        t = tempfn_random(path);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_random(path, &t);
+        if (r < 0)
+                return r;
 
         if (mknod(t, mode, dev) < 0)
                 return -errno;
@@ -4441,12 +4446,13 @@ int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
 
 int mkfifo_atomic(const char *path, mode_t mode) {
         _cleanup_free_ char *t = NULL;
+        int r;
 
         assert(path);
 
-        t = tempfn_random(path);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_random(path, &t);
+        if (r < 0)
+                return r;
 
         if (mkfifo(t, mode) < 0)
                 return -errno;
@@ -5558,7 +5564,7 @@ int get_shell(char **_s) {
         return 0;
 }
 
-bool filename_is_safe(const char *p) {
+bool filename_is_valid(const char *p) {
 
         if (isempty(p))
                 return false;
@@ -6960,42 +6966,45 @@ int fflush_and_check(FILE *f) {
         return 0;
 }
 
-char *tempfn_xxxxxx(const char *p) {
+int tempfn_xxxxxx(const char *p, char **ret) {
         const char *fn;
         char *t;
-        size_t k;
 
         assert(p);
+        assert(ret);
+
+        fn = basename(p);
+        if (!filename_is_valid(fn))
+                return -EINVAL;
 
         t = new(char, strlen(p) + 1 + 6 + 1);
         if (!t)
-                return NULL;
-
-        fn = basename(p);
-        k = fn - p;
+                return -ENOMEM;
 
-        strcpy(stpcpy(stpcpy(mempcpy(t, p, k), "."), fn), "XXXXXX");
+        strcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), "."), fn), "XXXXXX");
 
-        return t;
+        *ret = t;
+        return 0;
 }
 
-char *tempfn_random(const char *p) {
+int tempfn_random(const char *p, char **ret) {
         const char *fn;
         char *t, *x;
         uint64_t u;
-        size_t k;
         unsigned i;
 
         assert(p);
+        assert(ret);
+
+        fn = basename(p);
+        if (!filename_is_valid(fn))
+                return -EINVAL;
 
         t = new(char, strlen(p) + 1 + 16 + 1);
         if (!t)
-                return NULL;
-
-        fn = basename(p);
-        k = fn - p;
+                return -ENOMEM;
 
-        x = stpcpy(stpcpy(mempcpy(t, p, k), "."), fn);
+        x = stpcpy(stpcpy(mempcpy(t, p, fn - p), "."), fn);
 
         u = random_u64();
         for (i = 0; i < 16; i++) {
@@ -7005,7 +7014,8 @@ char *tempfn_random(const char *p) {
 
         *x = 0;
 
-        return t;
+        *ret = t;
+        return 0;
 }
 
 /* make sure the hostname is not "localhost" */