Simplify handling of /DETACH socket path

init_socketpath() was building a sprintf() format string intended to be used by /DETACH to create the socket
file name.  This included the actual socket path, plus a %d for the port, plus the sanitised tty name and
hostname.

Only one caller needed all this though - the /DETACH command - and the other callers (in scr-bx.c) just
wanted to truncate it to the actual socket path.  The format string also wasn't safe - if the home directory
path, hostname or ttyname contained % characters these werent being escaped.

It simplifies things to have init_socketpath() just return the actual socket path, after creating the 'screens'
directory if necessary.  This lets the code in scr-bx.c use it as-is, and removes the need for the global
socket_path variable.  The code to include the sanitised tty name and hostname in the socket file name can
be moved to the create_ipc_socket() function.

There's no need to check access() for the socket path before trying to create it - just call mkdir() regardless,
since it will fail if the path already exists, which is fine.

This commit also adds error handling to the create_ipc_socket() function for the case where creation of the
socket file fails, and switches the chmod() and chown() for the opened file to the more appropriate fchmod()
and fchown().

Changelog

@@ -1,5 +1,7 @@
 [Changes 1.2.2]
 
+* Simplify handling of /DETACH socket path. (caf)
+
 * Remove netfinger client code (no-one is running fingerd anymore) and
   repurpose /FINGER command to send a CTCP FINGER instead. (caf)
 

include/irc.h

@@ -344,7 +344,7 @@ extern short ospeed;
 #endif
 
 void reattach_tty(char *, char *);
-void init_socketpath(void);
+const char *init_socketpath(void);
 void kill_attached_if_needed(int);
 void setup_pid();
 

source/commands2.c

@@ -2379,7 +2379,6 @@ extern HMQ hmq;
 
 #if !defined(__EMX__) && !defined(WINNT) && !defined(GUI) && defined(WANT_DETACH)
 #ifndef PUBLIC_ACCESS
-extern char socket_path[];
 extern char *old_pass;
 
 int displays = 0;
@@ -2531,11 +2530,12 @@ void make_cookie(void)
 
 static int create_ipc_socket(void)
 {
-	int	s = -1, u = -1;
+	int	s, u;
 	unsigned short port = 0;
-	char buf[BIG_BUFFER_SIZE+1];
-
-	init_socketpath();
+	char buf[BIG_BUFFER_SIZE];
+	char host[BIG_BUFFER_SIZE];
+	char *p;
+	const char *socket_path = init_socketpath();
 
 	if ((s = connect_by_number("127.0.0.1", &port, SERVICE_SERVER, PROTOCOL_TCP, 0)) < 0)
 	{
@@ -2543,19 +2543,33 @@ static int create_ipc_socket(void)
 		return 1;
 	}
 
-	sprintf(buf, socket_path, port);
-	if ((u = open(buf, O_CREAT|O_WRONLY, 0600)) != -1)
+	gethostname(host, sizeof host);
+	if ((p = strchr(host, '.')))
+		*p = 0;
+
+	snprintf(buf, sizeof buf, "%s/%u.%s.%s", socket_path, (unsigned)port, stripdev(attach_ttyname), host);
+
+	if (strlen(socket_path) + 1 < sizeof buf)
+		for (p = buf + strlen(socket_path) + 1; *p; p++)
+			if (*p == '/')
+				*p = '-';
+
+	if ((u = open(buf, O_CREAT|O_WRONLY, 0600)) < 0)
 	{
-		chmod(buf, SOCKMODE);
-		chown(buf, getuid(), getgid());
+		bitchsay("Error creating IPC file: %s", strerror(errno));
+		new_close(s);
+		return 1;
+	}
+
+	fchmod(u, SOCKMODE);
+	fchown(u, getuid(), getgid());
 	make_cookie();
 	write(u, connect_cookie, strlen(connect_cookie));
 	write(u, "\n", 1);
 	close(u);
-	}
 
 	set_non_blocking(s);
-	add_socketread(s, port, 0, socket_path, handle_reconnect, NULL);
+	add_socketread(s, port, 0, NULL, handle_reconnect, NULL);
 	save_ipc = s;
 
 	return 0;

source/irc.c

@@ -165,7 +165,6 @@ char	*invite_channel = NULL,		/* last channel of an INVITE */
 	realname[REALNAME_LEN + 1],	/* real name of user */
 	username[NAME_LEN + 1],		/* usernameof user */
 	attach_ttyname[500],		/* ttyname for this term */
-	socket_path[500],		/* ttyname for this term */
 	*forwardnick = NULL,		/* used for /forward */
 	*send_umode = NULL,		/* sent umode */
 	*args_str = NULL,		/* list of command line args */
@@ -1502,7 +1501,6 @@ int main(int argc, char *argv[], char *envp[])
 	
 	channel = parse_args(argv, argc, envp);
 	check_pid();
-	init_socketpath();
 
 #ifdef WANT_TCL
 	tcl_interp = Tcl_CreateInterp();

source/ircaux.c

@@ -2871,38 +2871,16 @@ char *BX_stripdev(char *ttynam)
 	return ttynam;
 }
 
-
-void init_socketpath(void)
+const char *init_socketpath(void)
 {
-#if !defined(__EMX__) && !defined(WINNT)
-struct stat st;
-extern char socket_path[], attach_ttyname[];
+	static char socket_path[BIG_BUFFER_SIZE];
+
+	snprintf(socket_path, sizeof socket_path, "%s/.BitchX/screens", my_path);
 
-	sprintf(socket_path, "%s/.BitchX/screens", my_path);
-	if (access(socket_path, F_OK))
-	{
 	if (mkdir(socket_path, 0700) != -1)
 		(void)chown(socket_path, getuid(), getgid());
-		else
-			return;
-	}
-	if (stat(socket_path, &st) != -1)
-	{
-		char host[BIG_BUFFER_SIZE+1];
-		char *ap;
-		if (!S_ISDIR(st.st_mode))
-			return;
-		gethostname(host, BIG_BUFFER_SIZE);
-		if ((ap = strchr(host, '.')))
-			*ap = 0;
-		ap = &socket_path[strlen(socket_path)];
-		sprintf(ap, "/%%d.%s.%s", stripdev(attach_ttyname), host);
-		ap++;
-		for ( ; *ap; ap++)
-			if (*ap == '/')
-				*ap = '-';
-	}	        
-#endif
+
+	return socket_path;
 }
 
 /*

source/scr-bx.c

@@ -44,9 +44,7 @@ unsigned char   transToClient[256];    /* Server to client translation. */
 int dumb_mode = 0;
 int already_detached = 1;
 int do_check_pid = 0;
-char socket_path[500];
-char attach_ttyname[500];
-
+char *my_path;
 
 struct param 
 {
@@ -177,22 +175,18 @@ char *q;
 	return ttypath;
 }
 
-void display_socket_list(char *path, int unl, char *arg)
+void display_socket_list(const char *path, int unl, char *arg)
 {
 	DIR	*dptr;
 	struct dirent *dir;
 	struct stat st;
 	char buffer[2000];
-char *new_path, *p;
 	int count = 0;
 	int doit = 0;
 
-	new_path = LOCAL_COPY(path);
-	if ((p = strrchr(new_path, '/')))
-		*p = 0;
-	if (!(dptr = opendir(new_path)))
+	if (!(dptr = opendir(path)))
 	{
-		fprintf(stderr, "No such directory %s\r\n ", new_path);
+		fprintf(stderr, "No such directory %s\n", path);
 		exit(1);
 	}
 	while ((dir = readdir(dptr)))
@@ -202,7 +196,7 @@ int doit = 0;
 			continue;
 		if (dir->d_name[0] == '.')
 			continue;
-		sprintf(buffer, "%s/%s", new_path, dir->d_name);
+		sprintf(buffer, "%s/%s", path, dir->d_name);
 		if ((stat(buffer, &st) == -1))
 			continue;
 		if (arg && strstr(dir->d_name, arg))
@@ -229,20 +223,15 @@ int doit = 0;
 	exit(1);
 }
 
-char *find_detach_socket(char *path, char *name)
+char *find_detach_socket(const char *path, char *name)
 {
-char	*new_path;
 	DIR	*dptr;
 	struct	dirent	*dir;
 	struct	stat	st;
 	char *ret = NULL, *p;
 	int count = 0;
-	new_path = LOCAL_COPY(path);
-	if ((p = strrchr(new_path, '/')))
-		*p = 0;
-	else
-		return NULL;
-	if (!(dptr = opendir(new_path)))
+
+	if (!(dptr = opendir(path)))
 		return NULL;
 	ret = malloc(2000);
 	*ret = 0;
@@ -253,7 +242,7 @@ int count = 0;
 			continue;
 		if (dir->d_name[0] == '.')
 			continue;
-		sprintf(ret, "%s/%s", new_path, dir->d_name);
+		sprintf(ret, "%s/%s", path, dir->d_name);
 		p = strrchr(ret, '/'); p++;
 		if ((stat(ret, &st) == -1) || (st.st_uid != getuid()) || S_ISDIR(st.st_mode))
 		{
@@ -320,7 +309,7 @@ SIGNAL_HANDLER(handle_pipe)
 	term_cr();
 	term_clear_to_eol();
 	term_reset2();
-	fprintf(stdout, "\rdetached from %s. To re-attach type scr-bx %s\n\r", attach_ttyname, old_pass? "password":"");
+	fprintf(stdout, "\rdetached from %s. To re-attach type scr-bx %s\n\r", ttyname(0), old_pass? "password":"");
 	fflush(stdout);
 	exit(0);
 }
@@ -396,6 +385,8 @@ int port = 0;
 #if defined (TIOCGWINSZ)
 	struct winsize window;
 #endif
+	const char *socket_path = init_socketpath();
+
 	memset(&parm, 0, sizeof(struct param));
 
 	if (!(name = find_detach_socket(socket_path, tty)))
@@ -528,53 +519,17 @@ struct winsize window;
 	return; /* error return */
 }
 
-char *stripdev(char *ttynam)
+const char *init_socketpath(void)
 {
-	if (ttynam == NULL)
-		return NULL;
-#ifdef SVR4
-  /* unixware has /dev/pts012 as synonym for /dev/pts/12 */
-	if (!strncmp(ttynam, "/dev/pts", 8) && ttynam[8] >= '0' && ttynam[8] <= '9')
-	{
-		static char b[13];
-		sprintf(b, "pts/%d", atoi(ttynam + 8));
-		return b;
-	}
-#endif /* SVR4 */
-	if (!strncmp(ttynam, "/dev/", 5))
-		return ttynam + 5;
-	return ttynam;
-}
+	static char socket_path[BIG_BUFFER_SIZE];
 
+	snprintf(socket_path, sizeof socket_path, "%s/.BitchX/screens", my_path);
 
-void init_socketpath(void)
-{
-#if !defined(__EMX__) && !defined(WINNT)
-struct stat st;
-extern char socket_path[], attach_ttyname[];
+	if (mkdir(socket_path, 0700) != -1)
+		(void)chown(socket_path, getuid(), getgid());
 
-	sprintf(socket_path, "%s/.BitchX/screens", getenv("HOME"));
-	if (access(socket_path, F_OK))
-		return;
-	if (stat(socket_path, &st) != -1)
-	{
-		char host[BIG_BUFFER_SIZE+1];
-		char *ap;
-		if (!S_ISDIR(st.st_mode))
-			return;
-		gethostname(host, BIG_BUFFER_SIZE);
-		if ((ap = strchr(host, '.')))
-			*ap = 0;
-		ap = &socket_path[strlen(socket_path)];
-		sprintf(ap, "/%%d.%s.%s", stripdev(attach_ttyname), host);
-		ap++;
-		for ( ; *ap; ap++)
-			if (*ap == '/')
-				*ap = '-';
+	return socket_path;
 }
-#endif
-}
-
 
 char *old_tty = NULL;
 void parse_args(int argc, char **argv)
@@ -618,7 +573,7 @@ int disp_sock = 0;
 		}
 	}
 	if (disp_sock)
-		display_socket_list(socket_path, disp_sock - 1, old_tty);
+		display_socket_list(init_socketpath(), disp_sock - 1, old_tty);
 }
 
 
@@ -627,9 +582,7 @@ int main(int argc, char **argv)
 #ifdef MEM_DEBUG
 	dmalloc_debug(0x1df47dfb);
 #endif
-	*socket_path = 0;
-	strcpy(attach_ttyname, ttyname(0));
-	init_socketpath();
+	my_path = getenv("HOME");
 	parse_args(argc, argv);
 	chdir(getenv("HOME"));
 	reattach_tty(old_tty, old_pass);