X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=command.c;h=2bd101919eafa22136926ff244d12d13866fabac;hp=93e664e67fdf336df179277b2c7e1e667818ac27;hb=c4ecbd8f75be7847f7332dd64f11a0ba54233891;hpb=d431f957ebaeecc20685ac49a8c96e56cdef43f6

diff --git a/command.c b/command.c
index 93e664e6..2bd10191 100644
--- a/command.c
+++ b/command.c
@@ -20,7 +20,7 @@
 
 #include <sys/time.h> /* gettimeofday */
 #include "server.cmdline.h"
-#include "db.h"
+#include "afs.h"
 #include "server.h"
 #include "vss.h"
 #include "send.h"
@@ -34,6 +34,9 @@
 #include "user_list.h"
 #include "server_command_list.h"
 
+/** commands including options must be shorter than this */
+#define MAX_COMMAND_LEN 4096
+
 static RC4_KEY rc4_recv_key;
 static RC4_KEY rc4_send_key;
 static unsigned char rc4_buf[2 * RC4_KEY_LEN];
@@ -42,8 +45,6 @@ extern const char *status_item_list[NUM_STAT_ITEMS];
 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)
 {}
@@ -72,12 +73,12 @@ 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));
 
-	msg[0] = perms & DB_READ? 'a' : '-';
-	msg[1] = perms & DB_WRITE? 'A' : '-';
+	msg[0] = perms & AFS_READ? 'a' : '-';
+	msg[1] = perms & AFS_WRITE? 'A' : '-';
 	msg[2] = perms & VSS_READ? 'v' : '-';
 	msg[3] = perms & VSS_WRITE? 'V' : '-';
 	msg[4] = '\0';
@@ -102,7 +103,7 @@ 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;
@@ -112,14 +113,14 @@ char *get_sb_string(struct misc_meta_data *nmmd)
 		return para_strdup("");
 	if (!base[0])
 		return base;
-	if (nmmd->chunks_total) {
-		secs = (long long) nmmd->seconds_total * nmmd->chunks_sent
-			/ nmmd->chunks_total;
-		rsecs = (long long) nmmd->seconds_total *
-			(nmmd->chunks_total - nmmd->chunks_sent)
-			/ nmmd->chunks_total;
+	if (nmmd->afi.chunks_total) {
+		secs = (long long) nmmd->afi.seconds_total * nmmd->chunks_sent
+			/ nmmd->afi.chunks_total;
+		rsecs = (long long) nmmd->afi.seconds_total *
+			(nmmd->afi.chunks_total - nmmd->chunks_sent)
+			/ nmmd->afi.chunks_total;
 		percent = 100 * ((nmmd->chunks_sent + 5) / 10)
-			/ ((nmmd->chunks_total + 5) / 10);
+			/ ((nmmd->afi.chunks_total + 5) / 10);
 	}
 	ret = make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
 		secs / 60, secs % 60,
@@ -150,13 +151,13 @@ static char *get_status(struct misc_meta_data *nmmd)
 	bar = para_basename(nmmd->filename);
 	gettimeofday(&now, NULL);
 	ret = make_message(
-		"%s:%lu\n"	"%s:%s\n"		"%s:%i\n"	"%s:%u\n"
+		"%s:%zu\n"	"%s:%s\n"		"%s:%lu\n"	"%s:%u\n"
 		"%s:%s\n"	"%s:%s\n"	"%s:%s\n"	"%s:%s\n"
 		"%s:%li\n" 	"%s:%s\n"	"%s"		"%s"
 		"%s:%s\n"	"%s:%lu.%lu\n"	"%s:%lu.%lu\n",
 		status_item_list[SI_FILE_SIZE], nmmd->size / 1024,
 		status_item_list[SI_MTIME], mtime,
-		status_item_list[SI_LENGTH], nmmd->seconds_total,
+		status_item_list[SI_LENGTH], nmmd->afi.seconds_total,
 		status_item_list[SI_NUM_PLAYED], nmmd->num_played,
 
 		status_item_list[SI_STATUS_BAR], bar ? bar : "(none)",
@@ -167,7 +168,7 @@ static char *get_status(struct misc_meta_data *nmmd)
 		status_item_list[SI_OFFSET], offset,
 		status_item_list[SI_FORMAT], audio_format_name(nmmd->audio_format),
 		nmmd->selector_info,
-		nmmd->audio_file_info,
+		nmmd->afi.info_string,
 
 		status_item_list[SI_UPTIME], ut,
 		status_item_list[SI_STREAM_START],
@@ -342,20 +343,18 @@ int com_si(int fd, int argc, __a_unused char **argv)
 }
 
 /* version */
-int com_version(int socket_fd, int argc, __a_unused char **argv)
+int com_version(int 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(fd, VERSION_TEXT("server")
+		"built: " BUILD_DATE "\n"
+		SYSTEM ", " CC_VERSION "\n"
+	);
 }
 
 /* sc */
-int com_sc(int socket_fd, int argc, char **argv)
+int com_sc(int fd, int argc, char **argv)
 {
 	char *name = NULL;
 	int ret, old = 0, count = -1; /* print af change forever */
@@ -370,7 +369,7 @@ repeat:
 	}
 	mmd_unlock();
 	if (name) {
-		ret = send_va_buffer(socket_fd, "%s\n", name);
+		ret = send_va_buffer(fd, "%s\n", name);
 		free(name);
 		name = NULL;
 		if (ret < 0)
@@ -383,7 +382,7 @@ repeat:
 }
 
 /* sb */
-int com_sb(int socket_fd, int argc, char **argv)
+int com_sb(int fd, int argc, char **argv)
 {
 	char *sb;
 	int ret, nr = -1;	/* status bar will be printed that many
@@ -396,7 +395,7 @@ int com_sb(int socket_fd, int argc, char **argv)
 		mmd_lock();
 		sb = get_sb_string(mmd);
 		mmd_unlock();
-		ret = send_va_buffer(socket_fd, "%s\n", sb);
+		ret = send_va_buffer(fd, "%s\n", sb);
 		free(sb);
 		if (ret < 0)
 			return ret;
@@ -410,7 +409,7 @@ int com_sb(int socket_fd, int argc, char **argv)
 }
 
 /* stat */
-int com_stat(int socket_fd, int argc, char **argv)
+int com_stat(int fd, int argc, char **argv)
 {
 	int ret, num = 0;/* status will be printed that many
 			  * times. num <= 0 means: print forever
@@ -426,7 +425,7 @@ int com_stat(int socket_fd, int argc, char **argv)
 
 		mmd_dup(nmmd);
 		s = get_status(nmmd);
-		ret = send_buffer(socket_fd, s);
+		ret = send_buffer(fd, s);
 		free(s);
 		if (ret < 0)
 			goto out;
@@ -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);
@@ -528,7 +527,7 @@ int com_help(int fd, int argc, char **argv)
 }
 
 /* hup */
-int com_hup(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_hup(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -537,7 +536,7 @@ int com_hup(__a_unused int socket_fd, int argc, __a_unused char **argv)
 }
 
 /* term */
-int com_term(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_term(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -545,7 +544,7 @@ int com_term(__a_unused int socket_fd, int argc, __a_unused char **argv)
 	return 1;
 }
 
-int com_play(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_play(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -558,7 +557,7 @@ int com_play(__a_unused int socket_fd, int argc, __a_unused char **argv)
 }
 
 /* stop */
-int com_stop(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_stop(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -571,7 +570,7 @@ int com_stop(__a_unused int socket_fd, int argc, __a_unused char **argv)
 }
 
 /* pause */
-int com_pause(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_pause(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -610,7 +609,7 @@ int com_chs(int fd, int argc, char **argv)
 }
 
 /* next */
-int com_next(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_next(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -622,7 +621,7 @@ int com_next(__a_unused int socket_fd, int argc, __a_unused char **argv)
 }
 
 /* nomore */
-int com_nomore(__a_unused int socket_fd, int argc, __a_unused char **argv)
+int com_nomore(__a_unused int fd, int argc, __a_unused char **argv)
 {
 	if (argc != 1)
 		return -E_COMMAND_SYNTAX;
@@ -634,7 +633,7 @@ int com_nomore(__a_unused int socket_fd, int argc, __a_unused char **argv)
 }
 
 /* ff */
-int com_ff(__a_unused int socket_fd, int argc, char **argv)
+int com_ff(__a_unused int fd, int argc, char **argv)
 {
 	long promille;
 	int ret, backwards = 0;
@@ -649,20 +648,20 @@ int com_ff(__a_unused int socket_fd, int argc, char **argv)
 		backwards = 1; /* jmp backwards */
 	mmd_lock();
 	ret = -E_NO_AUDIO_FILE;
-	if (!mmd->chunks_total || !mmd->seconds_total)
+	if (!mmd->afi.chunks_total || !mmd->afi.seconds_total)
 		goto out;
-	promille = (1000 * mmd->current_chunk) / mmd->chunks_total;
+	promille = (1000 * mmd->current_chunk) / mmd->afi.chunks_total;
 	if (backwards)
-		promille -= 1000 * i / mmd->seconds_total;
+		promille -= 1000 * i / mmd->afi.seconds_total;
 	else
-		promille += 1000 * i / mmd->seconds_total;
+		promille += 1000 * i / mmd->afi.seconds_total;
 	if (promille < 0)
 		promille = 0;
 	if (promille >  1000) {
 		mmd->new_vss_status_flags |= VSS_NEXT;
 		goto out;
 	}
-	mmd->repos_request = (mmd->chunks_total * promille) / 1000;
+	mmd->repos_request = (mmd->afi.chunks_total * promille) / 1000;
 	mmd->new_vss_status_flags |= VSS_REPOS;
 	mmd->new_vss_status_flags &= ~VSS_NEXT;
 	mmd->events++;
@@ -673,7 +672,7 @@ out:
 }
 
 /* jmp */
-int com_jmp(__a_unused int socket_fd, int argc, char **argv)
+int com_jmp(__a_unused int fd, int argc, char **argv)
 {
 	long unsigned int i;
 	int ret;
@@ -684,12 +683,12 @@ int com_jmp(__a_unused int socket_fd, int argc, char **argv)
 		return -E_COMMAND_SYNTAX;
 	mmd_lock();
 	ret = -E_NO_AUDIO_FILE;
-	if (!mmd->chunks_total)
+	if (!mmd->afi.chunks_total)
 		goto out;
 	if (i > 100)
 		i = 100;
 	PARA_INFO_LOG("jumping to %lu%%\n", i);
-	mmd->repos_request = (mmd->chunks_total * i + 50)/ 100;
+	mmd->repos_request = (mmd->afi.chunks_total * i + 50)/ 100;
 	PARA_INFO_LOG("sent: %lu,  offset before jmp: %lu\n",
 		mmd->chunks_sent, mmd->offset);
 	mmd->new_vss_status_flags |= VSS_REPOS;
@@ -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)));
 }
@@ -757,16 +756,84 @@ static void rc4_send(unsigned long len, const unsigned char *indata,
 	RC4(&rc4_send_key, len, indata, outdata);
 }
 
+static int read_command(int fd, char **result)
+{
+	int ret;
+	char buf[4096];
+	char *command = NULL;
+
+	for (;;) {
+		size_t numbytes;
+		char *p;
+
+		ret = recv_buffer(fd, buf, sizeof(buf));
+		if (ret < 0)
+			goto out;
+		if (!ret)
+			break;
+		numbytes = ret;
+		ret = -E_COMMAND_SYNTAX;
+		if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
+			goto out;
+		command = para_strcat(command, buf);
+		p = strstr(command, EOC_MSG);
+		if (p) {
+			*p = '\0';
+			break;
+		}
+	}
+	ret = command? 1 : -E_COMMAND_SYNTAX;
+out:
+	if (ret < 0)
+		free(command);
+	else
+		*result = command;
+	return ret;
+
+}
+
+/**
+ * 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;
-	char buf[STRINGSIZE];
+	int ret, argc, use_rc4 = 0;
+	char buf[4096];
 	unsigned char crypt_buf[MAXLINE];
-	struct user u;
+	struct user *u;
 	struct server_command *cmd = NULL;
 	long unsigned challenge_nr, chall_response;
 	char **argv = NULL;
 	char *p, *command = NULL;
+	size_t numbytes;
 
 	signal(SIGCHLD, SIG_IGN);
 	signal(SIGINT, SIG_DFL);
@@ -774,7 +841,6 @@ 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 "
@@ -795,16 +861,18 @@ int handle_connect(int fd, struct sockaddr_in *addr)
 		goto err_out;
 
 	if (numbytes < 9 || strncmp(buf, "auth rc4 ", 9))
-		u.name = para_strdup(buf + 5); /* client version < 0.2.6 */
+		p = buf + 5; /* client version < 0.2.6 */
 	else {
-		u.name = para_strdup(buf + 9); /* client version >= 0.2.6 */
+		p = buf + 9; /* client version >= 0.2.6 */
 		use_rc4 = 1;
 	}
 	PARA_DEBUG_LOG("received %s request for user %s\n",
-		use_rc4? "rc4" : "auth", u.name);
-	if ((ret = lookup_user(&u)) < 0)
+		use_rc4? "rc4" : "auth", p);
+	ret = -E_BAD_USER;
+	u = lookup_user(p);
+	if (!u)
 		goto err_out;
-	ret = para_encrypt_challenge(u.rsa, challenge_nr, crypt_buf);
+	ret = para_encrypt_challenge(u->rsa, challenge_nr, crypt_buf);
 	if (ret <= 0)
 		goto err_out;
 	numbytes = ret;
@@ -814,22 +882,22 @@ int handle_connect(int fd, struct sockaddr_in *addr)
 	if (ret < 0)
 		goto err_out;
 	/* recv decrypted number */
-	numbytes = recv_buffer(fd, buf, sizeof(buf));
-	ret = numbytes;
+	ret = recv_buffer(fd, buf, sizeof(buf));
 	if (ret < 0)
 		goto err_out;
+	numbytes = ret;
 	ret = -E_AUTH;
 	if (!numbytes)
 		goto err_out;
 	if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1
 			|| chall_response != challenge_nr)
 		goto err_out;
-	/* auth successful. Send 'Proceed' message */
-	PARA_INFO_LOG("good auth for %s (%lu)\n", u.name, challenge_nr);
+	/* auth successful, send 'Proceed' message */
+	PARA_INFO_LOG("good auth for %s (%lu)\n", u->name, challenge_nr);
 	sprintf(buf, "%s", PROCEED_MSG);
 	if (use_rc4) {
 		init_rc4_keys();
-		ret = para_encrypt_buffer(u.rsa, rc4_buf, 2 * RC4_KEY_LEN,
+		ret = para_encrypt_buffer(u->rsa, rc4_buf, 2 * RC4_KEY_LEN,
 			(unsigned char *)buf + PROCEED_MSG_LEN + 1);
 		if (ret <= 0)
 			goto err_out;
@@ -841,27 +909,15 @@ int handle_connect(int fd, struct sockaddr_in *addr)
 		goto err_out;
 	if (use_rc4)
 		enable_crypt(fd, rc4_recv, rc4_send, NULL);
-	/* read command */
-	while ((numbytes = recv_buffer(fd, buf, sizeof(buf))) > 0) {
-//		PARA_INFO_LOG("recvd: %s (%d)\n", buf, numbytes);
-		ret = -E_COMMAND_SYNTAX;
-		if (command && numbytes + strlen(command) > STRINGSIZE) /* DOS */
-			goto err_out;
-		command = para_strcat(command, buf);
-		if ((p = strstr(command, EOC_MSG))) {
-			*p = '\0';
-			break;
-		}
-	}
-	ret = numbytes;
+	ret = read_command(fd, &command);
 	if (ret < 0)
 		goto err_out;
 	ret = -E_BAD_CMD;
-	/* parse command */
-	if (!(cmd = parse_cmd(command)))
+	cmd = parse_cmd(command);
+	if (!cmd)
 		goto err_out;
 	/* valid command, check permissions */
-	ret = check_perms(u.perms, cmd);
+	ret = check_perms(u->perms, cmd);
 	if (ret < 0)
 		goto err_out;
 	/* valid command and sufficient perms */
@@ -870,7 +926,7 @@ int handle_connect(int fd, struct sockaddr_in *addr)
 	mmd_lock();
 	mmd->num_commands++;
 	mmd_unlock();
-	PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u.name,
+	PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
 		inet_ntoa(addr->sin_addr));
 	ret = cmd->handler(fd, argc, argv);
 	if (ret >= 0) {
@@ -878,16 +934,15 @@ int handle_connect(int fd, struct sockaddr_in *addr)
 		goto out;
 	}
 err_out:
-	if (ret != -E_SEND && ret != -E_RECV) {
-		PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
+	PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
+	if (ret != -E_SEND && ret != -E_RECV)
 		send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
-	}
 	ret = EXIT_FAILURE;
 out:
 	free(command);
 	free(argv);
 	mmd_lock();
-	if (cmd && (cmd->perms & DB_WRITE) && ret >= 0)
+	if (cmd && (cmd->perms & AFS_WRITE) && ret >= 0)
 		mmd->events++;
 	mmd->active_connections--;
 	mmd_unlock();