X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=command.c;h=9ef629257134e4d8cad97fc344b30e0be473956d;hp=928990e6911a8cb5b52b2a0ed6f3aea41bf611e1;hb=0d1f4c9472f62954f296c1db5eec7e1525ec9637;hpb=1446f99e3adc59d868726382a2ac7cec105372a7

diff --git a/command.c b/command.c
index 928990e6..9ef62925 100644
--- a/command.c
+++ b/command.c
@@ -43,7 +43,6 @@ extern struct misc_meta_data *mmd;
 extern struct audio_file_selector selectors[];
 extern struct sender senders[];
 extern char *user_list;
-struct sockaddr_in *in_addr;
 
 static void dummy(__a_unused int s)
 {}
@@ -72,7 +71,7 @@ static char *vss_status_tohuman(unsigned int flags)
 /*
  * return human readable permission string. Never returns NULL.
  */
-char *cmd_perms_itohuman(unsigned int perms)
+static char *cmd_perms_itohuman(unsigned int perms)
 {
 	char *msg = para_malloc(5 * sizeof(char));
 
@@ -102,7 +101,7 @@ static char *vss_get_status_flags(unsigned int flags)
 /*
  * compute status bar string. Never returns NULL
  */
-char *get_sb_string(struct misc_meta_data *nmmd)
+static char *get_sb_string(struct misc_meta_data *nmmd)
 {
 	char *base, *ret;
 	long long unsigned secs = 0, rsecs = 0, percent = 0;
@@ -346,12 +345,10 @@ int com_version(int socket_fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
-	return send_buffer(socket_fd, "para_server-" PACKAGE_VERSION ", \""
-			CODENAME "\"\n"
-			COPYRIGHT "\n"
-			"built: " BUILD_DATE "\n"
-			SYSTEM ", " CC_VERSION "\n"
-		);
+	return send_buffer(socket_fd, VERSION_TEXT("server")
+		"built: " BUILD_DATE "\n"
+		SYSTEM ", " CC_VERSION "\n"
+	);
 }
 
 /* sc */
@@ -727,7 +724,7 @@ static struct server_command *parse_cmd(const char *cmdstr)
 	return get_cmd_ptr(buf, NULL);
 }
 
-long int para_rand(long unsigned max)
+static long int para_rand(long unsigned max)
 {
 	return (long int) ((max + 0.0) * (random() / (RAND_MAX + 1.0)));
 }
@@ -757,6 +754,37 @@ static void rc4_send(unsigned long len, const unsigned char *indata,
 	RC4(&rc4_send_key, len, indata, outdata);
 }
 
+/**
+ * perform user authentication and execute a command
+ *
+ * \param fd the file descriptor to send output to
+ * \param addr socket address info of peer
+ *
+ * \return EXIT_SUCCESS or EXIT_FAILURE
+ *
+ * Whenever para_server accepts an incoming tcp connection on
+ * the port it listens on, it forks and the resulting child
+ * calls this function.
+ *
+ * An RSA-based challenge/response is used to authenticate
+ * the peer. It that authentication succeeds, a random RC4
+ * session key is generated and sent back to the peer,
+ * encrypted with its RSA public key.  From this point on,
+ * all transfers are crypted with this session key.
+ *
+ * Next it is checked if the peer supplied  a valid server
+ * command or a command for the audio file selector currently
+ * in use.  If yes, and if the user has sufficient
+ * permissions to execute that command, the function calls
+ * the corresponding command handler which does argument
+ * checking and further processing.
+ *
+ * In order to cope with a DOS attacks, a timeout is set up
+ * which terminates the function if the connection was not
+ * authenticated when the timeout expires.
+ *
+ * \sa alarm(2), rc4(3), crypt.c, crypt.h
+ */
 int handle_connect(int fd, struct sockaddr_in *addr)
 {
 	int numbytes, ret, argc, use_rc4 = 0;
@@ -774,7 +802,6 @@ int handle_connect(int fd, struct sockaddr_in *addr)
 	signal(SIGHUP, SIG_DFL);
 	signal(SIGUSR1, SIG_IGN);
 
-	in_addr = addr;
 	challenge_nr = random();
 	/* send Welcome message */
 	ret = send_va_buffer(fd, "This is para_server, version "