t6034: use modern test_* helpers
[gitweb.git] / daemon.c
index 09fa652fd172cf7bb5b1cf8a4f0ccbc072ca2111..c3edd960ec5bf686b66fa55dcfea712e455fe772 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -536,6 +536,45 @@ static void parse_host_and_port(char *hostport, char **host,
        }
 }
 
+/*
+ * Sanitize a string from the client so that it's OK to be inserted into a
+ * filesystem path. Specifically, we disallow slashes, runs of "..", and
+ * trailing and leading dots, which means that the client cannot escape
+ * our base path via ".." traversal.
+ */
+static void sanitize_client_strbuf(struct strbuf *out, const char *in)
+{
+       for (; *in; in++) {
+               if (*in == '/')
+                       continue;
+               if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
+                       continue;
+               strbuf_addch(out, *in);
+       }
+
+       while (out->len && out->buf[out->len - 1] == '.')
+               strbuf_setlen(out, out->len - 1);
+}
+
+static char *sanitize_client(const char *in)
+{
+       struct strbuf out = STRBUF_INIT;
+       sanitize_client_strbuf(&out, in);
+       return strbuf_detach(&out, NULL);
+}
+
+/*
+ * Like sanitize_client, but we also perform any canonicalization
+ * to make life easier on the admin.
+ */
+static char *canonicalize_client(const char *in)
+{
+       struct strbuf out = STRBUF_INIT;
+       sanitize_client_strbuf(&out, in);
+       strbuf_tolower(&out);
+       return strbuf_detach(&out, NULL);
+}
+
 /*
  * Read the host as supplied by the client connection.
  */
@@ -557,10 +596,10 @@ static void parse_host_arg(char *extra_args, int buflen)
                                parse_host_and_port(val, &host, &port);
                                if (port) {
                                        free(tcp_port);
-                                       tcp_port = xstrdup(port);
+                                       tcp_port = sanitize_client(port);
                                }
                                free(hostname);
-                               hostname = xstrdup_tolower(host);
+                               hostname = canonicalize_client(host);
                                hostname_lookup_done = 0;
                        }
 
@@ -597,8 +636,9 @@ static void lookup_hostname(void)
                        ip_address = xstrdup(addrbuf);
 
                        free(canon_hostname);
-                       canon_hostname = xstrdup(ai->ai_canonname ?
-                                                ai->ai_canonname : ip_address);
+                       canon_hostname = ai->ai_canonname ?
+                               sanitize_client(ai->ai_canonname) :
+                               xstrdup(ip_address);
 
                        freeaddrinfo(ai);
                }
@@ -620,7 +660,7 @@ static void lookup_hostname(void)
                                  addrbuf, sizeof(addrbuf));
 
                        free(canon_hostname);
-                       canon_hostname = xstrdup(hent->h_name);
+                       canon_hostname = sanitize_client(hent->h_name);
                        free(ip_address);
                        ip_address = xstrdup(addrbuf);
                }