restore_env(): free the saved environment variable once we are done

diff --git a/transport.c b/transport.c
index eca9b8c817bd723532d7f92da8cfa9f8ee82bb43..164a716053ea6511a57bdcf27c3cd1810edfe36d 100644 (file)
--- a/transport.c
+++ b/transport.c
@@ -278,12 +278,11 @@ static int fetch_objs_via_rsync(struct transport *transport,
        return run_command(&rsync);
 }
 
-static int write_one_ref(const char *name, const unsigned char *sha1,
-               int flags, void *data)
+static int write_one_ref(const char *name, const struct object_id *oid,
+                        int flags, void *data)
 {
        struct strbuf *buf = data;
        int len = buf->len;
-       FILE *f;
 
        /* when called via for_each_ref(), flags is non-zero */
        if (flags && !starts_with(name, "refs/heads/") &&
@@ -292,27 +291,26 @@ static int write_one_ref(const char *name, const unsigned char *sha1,
 
        strbuf_addstr(buf, name);
        if (safe_create_leading_directories(buf->buf) ||
-                       !(f = fopen(buf->buf, "w")) ||
-                       fprintf(f, "%s\n", sha1_to_hex(sha1)) < 0 ||
-                       fclose(f))
-               return error("problems writing temporary file %s", buf->buf);
+           write_file(buf->buf, 0, "%s\n", oid_to_hex(oid)))
+               return error("problems writing temporary file %s: %s",
+                            buf->buf, strerror(errno));
        strbuf_setlen(buf, len);
        return 0;
 }
 
 static int write_refs_to_temp_dir(struct strbuf *temp_dir,
-               int refspec_nr, const char **refspec)
+                                 int refspec_nr, const char **refspec)
 {
        int i;
 
        for (i = 0; i < refspec_nr; i++) {
-               unsigned char sha1[20];
+               struct object_id oid;
                char *ref;
 
-               if (dwim_ref(refspec[i], strlen(refspec[i]), sha1, &ref) != 1)
+               if (dwim_ref(refspec[i], strlen(refspec[i]), oid.hash, &ref) != 1)
                        return error("Could not get ref %s", refspec[i]);
 
-               if (write_one_ref(ref, sha1, 0, temp_dir)) {
+               if (write_one_ref(ref, &oid, 0, temp_dir)) {
                        free(ref);
                        return -1;
                }
@@ -914,6 +912,42 @@ static int external_specification_len(const char *url)
        return strchr(url, ':') - url;
 }
 
+static const struct string_list *protocol_whitelist(void)
+{
+       static int enabled = -1;
+       static struct string_list allowed = STRING_LIST_INIT_DUP;
+
+       if (enabled < 0) {
+               const char *v = getenv("GIT_ALLOW_PROTOCOL");
+               if (v) {
+                       string_list_split(&allowed, v, ':', -1);
+                       string_list_sort(&allowed);
+                       enabled = 1;
+               } else {
+                       enabled = 0;
+               }
+       }
+
+       return enabled ? &allowed : NULL;
+}
+
+int is_transport_allowed(const char *type)
+{
+       const struct string_list *allowed = protocol_whitelist();
+       return !allowed || string_list_has_string(allowed, type);
+}
+
+void transport_check_allowed(const char *type)
+{
+       if (!is_transport_allowed(type))
+               die("transport '%s' not allowed", type);
+}
+
+int transport_restrict_protocols(void)
+{
+       return !!protocol_whitelist();
+}
+
 struct transport *transport_get(struct remote *remote, const char *url)
 {
        const char *helper;
@@ -945,12 +979,14 @@ struct transport *transport_get(struct remote *remote, const char *url)
        if (helper) {
                transport_helper_init(ret, helper);
        } else if (starts_with(url, "rsync:")) {
+               transport_check_allowed("rsync");
                ret->get_refs_list = get_refs_via_rsync;
                ret->fetch = fetch_objs_via_rsync;
                ret->push = rsync_transport_push;
                ret->smart_options = NULL;
        } else if (url_is_local_not_ssh(url) && is_file(url) && is_bundle(url, 1)) {
                struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
+               transport_check_allowed("file");
                ret->data = data;
                ret->get_refs_list = get_refs_from_bundle;
                ret->fetch = fetch_refs_from_bundle;
@@ -962,7 +998,10 @@ struct transport *transport_get(struct remote *remote, const char *url)
                || starts_with(url, "ssh://")
                || starts_with(url, "git+ssh://")
                || starts_with(url, "ssh+git://")) {
-               /* These are builtin smart transports. */
+               /*
+                * These are builtin smart transports; "allowed" transports
+                * will be checked individually in git_connect.
+                */
                struct git_transport_data *data = xcalloc(1, sizeof(*data));
                ret->data = data;
                ret->set_option = NULL;