Add support to redirection

README.md

@@ -1,7 +1,7 @@
 # A simplistic and secure Gemini server
 
 **Vger** is a gemini server supporting chroot, virtualhosts, default
-language choice and MIME types detection.
+language choice, redirections and MIME types detection.
 
 **Vger** design is relying on inetd and a daemon to take care of
 TLS.  The idea is to delegate TLS and network to daemons which
@@ -91,3 +91,5 @@ On OpenBSD, enable inetd and relayd and start them:
 # rcctl enable relayd inetd
 # rcctl start relayd inetd
 ```
+
+Vger will serve files named `index.gmi` if no explicite filename is given.

main.c

@@ -22,6 +22,7 @@
 
 void 		display_file(const char *, const char *);
 void 		status(const int, const char *, const char *);
+void		status_redirect(const int code, const char *url);
 void 		drop_privileges(const char *, const char *);
 void        eunveil(const char *path, const char *permissions);
 size_t      estrlcat(char *dst, const char *src, size_t dstsize);
@@ -127,6 +128,13 @@ status(const int code, const char *file_mime, const char *lang)
 	       code, file_mime, lang);
 }
 
+void
+status_redirect(const int code, const char *url)
+{
+	printf("%i %s\r\n",
+	       code, url);
+}
+
 void
 display_file(const char *path, const char *lang)
 {
@@ -135,19 +143,28 @@ display_file(const char *path, const char *lang)
 	ssize_t		 nread = 0;
 	char		*buffer[BUFSIZ];
 	const char	*file_mime;
+	char		target[FILENAME_MAX] = "";
 
-	/* this is to check if path is a directory */
-	if (stat(path, &sb) == -1)
+	/* this is to check if path exists and obtain metadata later */
+	if (stat(path, &sb) == -1) {
+
+		/* check if path is a symbolic link
+	         * if so, redirect using its target */
+                if (lstat(path, &sb) != -1 && S_ISLNK(sb.st_mode) == 1)
+		       	goto redirect;
+                else
+        		goto err;
+	}
+
+
+	/* check if directory */
+	if (S_ISDIR(sb.st_mode) == 1)
 		goto err;
 
 	/* open the file requested */
 	if ((fd = fopen(path, "r")) == NULL)
 		goto err;
 
-	/* check if directory */
-	if (S_ISDIR(sb.st_mode) == 1)
-		goto err;
-
 	file_mime = get_file_mime(path);
 
 	status(20, file_mime, lang);
@@ -165,9 +182,24 @@ err:
 	syslog(LOG_DAEMON, "path invalid %s", path);
 	goto closefd;
 
+redirect:
+    	/* read symbolic link target to redirect */
+	if (readlink(path, target, FILENAME_MAX) == -1) {
+    	     int  errnum = errno;
+    	            fprintf(stderr, "Value of errno: %d\n", errno);
+    	                  perror("Error printed by perror");
+    	                        fprintf(stderr, "Error opening file: %s\n", strerror( errnum ));
+     		goto err;
+	}
+
+    	status_redirect(39, target);
+    	syslog(LOG_DAEMON, "redirection from %s to %s", path, target);
+
 closefd:
+    	if (S_ISREG(sb.st_mode) == 1) {
         	fclose(fd);
     	}
+}
 
 int
 main(int argc, char **argv)

tests/test.sh

@@ -34,6 +34,10 @@ if ! [ $OUT = "e663f17730d5ddc24010c14a238e1e78" ] ; then echo "error" ; exit 1
 OUT=$(printf "gemini://perso.pw/foobar.unknown\r\n" | ../vger -d var/gemini/ -l fr | tee /dev/stderr | $MD5)
 if ! [ $OUT = "649a2e224632b679fd7599eafb13c001" ] ; then echo "error" ; exit 1 ; fi
 
+# redirect file
+OUT=$(printf "gemini://perso.pw/old_location\r\n" | ../vger -d var/gemini/ | tee /dev/stderr | $MD5)
+if ! [ $OUT = "28262311ea814e6a481fa365894cfc3f" ] ; then echo "error" ; exit 1 ; fi
+
 # file from local directory using virtualhosts
 OUT=$(printf "gemini://perso.pw/index.gmi\r\n" | ../vger -v -d var/gemini/ | tee /dev/stderr | $MD5)
 if ! [ $OUT = "0d36a423a4e8be813fda4022f08b3844" ] ; then echo "error" ; exit 1 ; fi

vger.8

@@ -20,6 +20,9 @@ behind a relay daemon offering TLS capabilities like
 If an incoming gemini query doesn't explicitly request a file,
 .Nm
 will serves a default "index.gmi" file if present.
+.Pp
+It is possible to create redirections by creating a symbolic link
+containing the new file location.
 .Sh OPTIONS
 .Bl -tag -width Ds
 .It Op Fl l Ar lang