From cf98ce3b053e6ea0b0271278f3dbd585e632ff5f Mon Sep 17 00:00:00 2001
From: Rafael Castillo <rafael@trfs.me>
Date: Thu, 12 Nov 2020 00:21:24 -0700
Subject: [PATCH] Basic mimetype detection

---
 main.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
 url.c  | 25 +++++++++++++++++++------
 url.h  |  2 +-
 3 files changed, 72 insertions(+), 9 deletions(-)

diff --git a/main.c b/main.c
index bb7c991..0534e71 100644
--- a/main.c
+++ b/main.c
@@ -3,6 +3,7 @@
 #include <string.h>
 #include <errno.h>
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <sys/socket.h>
 #include <unistd.h>
 #include <getopt.h>
@@ -50,6 +51,52 @@ struct Request {
 	enum RequestState state;
 };
 
+int
+append_index_rel(char *relpath)
+{
+  size_t len = strlen(relpath);
+  if (relpath[len - 1] == '/') {
+    strcat(relpath, "index.gmi");
+    return 1;
+
+  }
+  return 0;
+}
+
+int
+append_index_abs(char *abspath)
+{
+  struct stat path_stat;
+  stat(path, &path_stat);
+  size_t len = strlen(abspath);
+
+  if (!S_ISREG(path_stat.st_mode)) {
+    if (abspath[len - 1] != '/') {
+      strcat(abspath, "/");
+    }
+    strcat(abspath, "index.gmi");
+  }
+
+  return 1;
+}
+
+char *get_mimetype(char *path) {
+  char *ext = get_path_ext(path);
+  if (!ext) {
+    return "text/gemini";
+  }
+
+  if (strcmp(ext, "gmi") == 0) {
+    return "text/gemini";
+  }
+
+  if (strcmp(ext, "txt") == 0) {
+    return "text/plain";
+  }
+
+  return "text/plain";
+}
+
 int
 init_socket()
 {
@@ -258,10 +305,13 @@ read_request(struct bufferevent *bev, void *ctx)
   char datebuf[20];
   strftime (datebuf, sizeof(datebuf), "%Y-%m-%d %H:%M:%S", reqtime);
   printf("%s Serving request: %s\n", datebuf, line);
+  
+  char *mimetype = get_mimetype(url.route);
 
 	strcpy(path, rootdir);
-	append_index(url.route);
+	append_index_rel(url.route);
 	strcat(path, url.route);
+	append_index_abs(path);
 	int filefd = open(path, O_RDONLY);
 	if (filefd == -1) {
 		write_header(output, 51, "File not found");
@@ -273,7 +323,7 @@ read_request(struct bufferevent *bev, void *ctx)
 	fsize = lseek(filefd, 0, SEEK_END);
 	lseek(filefd, 0, SEEK_SET);
 
-	write_header(output, 20, "text/gemini");
+	write_header(output, 20, mimetype);
 	evbuffer_add_file(output, filefd, 0, fsize);
 }
 
diff --git a/url.c b/url.c
index 08f281a..4e0f165 100644
--- a/url.c
+++ b/url.c
@@ -142,14 +142,27 @@ relpath_is_safe(char *relpath)
   return check_segment(relpath, s, i);
 }
 
-int
-append_index(char *relpath)
+char *
+get_path_ext(char *relpath)
 {
-  size_t len = strlen(relpath);
-  if (relpath[len - 1] == '/') {
-    strcat(relpath, "index.gmi");
-    return 1;
+  size_t i = 0;
+  size_t s = 0;
+
+  while (relpath[i] != '\0') {
+    if (relpath[i] == '/') {
+      s = i + 1;
+    }
+    i++;
+  }
+
+  size_t len = i;
+
+  for (i = s; i < len; i++) {
+    if (relpath[i] == '.') {
+      return relpath + i + 1;
+    }
   }
 
   return 0;
 }
+
diff --git a/url.h b/url.h
index 7fa29cf..2f5a3b7 100644
--- a/url.h
+++ b/url.h
@@ -6,4 +6,4 @@ typedef struct URL {
 
 int parse_url(char *urlstring, URL *url);
 int relpath_is_safe(char *relpath);
-int append_index(char *relpath);
+char *get_path_ext(char *relpath);
-- 
2.45.2