X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=command.c;h=21131248c29cd894c8bb74cb13801cd54205e066;hp=93e664e67fdf336df179277b2c7e1e667818ac27;hb=41c4f81a98b916d134c1dcd4593e1c013041a06b;hpb=d431f957ebaeecc20685ac49a8c96e56cdef43f6

diff --git a/command.c b/command.c
index 93e664e6..21131248 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;
@@ -519,7 +518,7 @@ int com_help(int fd, int argc, char **argv)
 		cmd->description,
 		handler,
 		perms,
-		cmd->synopsis,
+		cmd->usage,
 		cmd->help
 	);
 	free(perms);
@@ -727,7 +726,7 @@ 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 +756,37 @@ 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 +804,6 @@ 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 "