Connect to unix sockets to interface with user-written programs.

.gitignore

@@ -1,2 +1,3 @@
 *.o
 vger
+unit_test

main.c

@@ -88,10 +88,10 @@ main(int argc, char **argv)
 	/* *** from here, cgi didn't run *** */
 
 	/* check if path available */
-	check_path(path, sizeof(path));
+	struct stat sb = check_path(path, sizeof(path));
 
 	/* regular file to stdout */
-	display_file(path);
+	display_file(path, sb);
 
 	stop(EXIT_SUCCESS, NULL);
 }

utils.h

@@ -1,3 +1,6 @@
+#ifndef utils_h_INCLUDED
+#define utils_h_INCLUDED
+
 void		getsubexp(const char *, regmatch_t, char *);
 void		echdir(const char *);
 void		epledge(const char *, const char *);
@@ -6,3 +9,5 @@ int		esetenv(const char *, const char *, int);
 size_t		esnprintf(char *, size_t, const char *, ...);
 size_t		print_file(FILE *fd);
 void		set_errmsg(const char *, ...);
+
+#endif // utils_h_INCLUDED

vger.c

@@ -1,6 +1,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 
 #include <ctype.h>
 #include <dirent.h>
@@ -175,20 +177,77 @@ set_rootdir(const char *chroot_dir, const char *cgi_dir, const char *user)
 }
 
 ssize_t
-display_file(const char *path)
+display_file(const char *path, struct stat sb)
 {
 	FILE           *fd = NULL;
 	const char     *file_mime;
+	size_t          pathlen = strlen(path);
 
 	/*
 	 * special case : path ends with "/". The user requested a dir
 	 */
-	if ((path[strlen(path)-1] == '/') && (doautoidx)) {
+	if ((path[pathlen-1] == '/') && (doautoidx)) {
 		/* no index.gmi, so display autoindex if enabled */
 		_datasiz += autoindex(path);
 		return _datasiz;
 	}
 
+	if (S_ISSOCK(sb.st_mode)) {
+		/* I got these numbers off of a Stack Overflow answer, so take them with a grain of salt. */
+#if defined(__OpenBSD__) || defined(__FreeBSD__) || defined( __NetBSD__) || defined(__DragonFly__)
+		if(pathlen > 104) {
+#elif defined(__linux__)
+		if(pathlen > 108) {
+#else
+#error "I don't know the max path length of a unix socket for this system!"
+#endif
+			/* If the name is too long. */
+			status(40, "%s", "socket name is too long");
+			return _datasiz;
+		}
+
+		/* Create the socket address (a filename, really). */
+		struct sockaddr_un addr;
+		memset(&addr, 0, sizeof(struct sockaddr_un));
+		addr.sun_family = AF_UNIX;
+		strncpy(addr.sun_path, path, pathlen);
+
+		/* Allocate a UNIX domain socket. */
+		int sock = socket(AF_UNIX, SOCK_STREAM, 0);
+
+		/* Connect to the desired socket. */
+		int ret = connect(sock, (const struct sockaddr *) &addr, sizeof(struct sockaddr_un));
+		if (ret == -1) {
+			status(43, "%s", "unable to connect to socket");
+			return _datasiz;
+		}
+
+		/* TODO: Move this to its own function. */
+		file_mime = get_file_mime(path, default_mime);
+		if (strcmp(file_mime, "text/gemini") == 0)
+			status(20, "%s; %s", file_mime, lang);
+		else
+			status(20, "%s", file_mime);
+
+		/* Read data until the socket is closed. */
+		char buffer[BUFSIZ];
+		for (;;) {
+			ret = read(sock, buffer, BUFSIZ);
+			if (ret == -1) {
+				_datasiz += fprintf(stdout, "\n\n\nsocket read error: %i\n", errno);
+				break;
+			} else if (ret == 0) {
+				break;			/* end of file */
+			} else {
+				fwrite(buffer, 1, ret, stdout);
+			}
+		}
+
+		/* We're done! */
+		close(sock);
+		return _datasiz;
+	}
+
 	/* open the file requested */
 	if ((fd = fopen(path, "r")) != NULL) {
 		file_mime = get_file_mime(path, default_mime);
@@ -398,7 +457,7 @@ remove_double_dot(char *request)
 	    memmove(request, pos + 3, strlen(pos) + 1 - 3); /* "/.." = 3 */
 }
 
-void
+struct stat
 check_path(char *path, size_t pathsiz)
 {
 	struct stat 	sb               = {0};
@@ -427,6 +486,8 @@ check_path(char *path, size_t pathsiz)
 		if (stat(tmp, &sb) == 0)
 			esnprintf(path, pathsiz, "%s", tmp);
 	}
+
+	return sb;
 }
 
 void

vger.h

@@ -42,8 +42,8 @@ static char 	_request[GEMINI_REQUEST_MAX]  = {'\0'};
 ssize_t 	autoindex(const char *);
 void		cgi(const char *);
 char *		read_request(char *);
-void		check_path(char *, size_t);
-ssize_t		display_file(const char *);
+struct stat	check_path(char *, size_t);
+ssize_t		display_file(const char *, struct stat);
 int		do_cgi(const char *, const char *, const char *, const char *);
 void 		drop_privileges(const char *);
 void		set_rootdir(const char *, const char *, const char *);