Implement autoindex option

3 files changed, 169 insertions, 25 deletions

diff --git a/src/config.c b/src/config.c
index f3172d2..f146aa0 100644
--- a/src/config.c
+++ b/src/config.c
@@ -1,8 +1,10 @@
 #include <assert.h>
 #include <errno.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <strings.h>
 #include "config.h"
 #include "ini.h"
 
@@ -146,6 +148,13 @@ conf_ini_handler(void *user, const char *section,
 		char **value;
 	} host_strvars[] = {
 		{ "root", &host->root },
+		{ "index", &host->index },
+	};
+	struct {
+		char *name;
+		bool *value;
+	} host_bvars[] = {
+		{ "autoindex", &host->autoindex },
 	};
 
 	for (size_t i = 0; i < sizeof(host_strvars) / sizeof(host_strvars[0]); ++i) {
@@ -156,6 +165,17 @@ conf_ini_handler(void *user, const char *section,
 		return 1;
 	}
 
+	for (size_t i = 0; i < sizeof(host_bvars) / sizeof(host_bvars[0]); ++i) {
+		if (strcmp(host_bvars[i].name, name) != 0) {
+			continue;
+		}
+		*host_bvars[i].value =
+			strcasecmp(value, "yes") == 0 ||
+			strcasecmp(value, "true") == 0 ||
+			strcasecmp(value, "on") == 0;
+		return 1;
+	}
+
 	fprintf(stderr, "Unknown config option [%s]%s\n", section, name);
 	return 0;
 }
diff --git a/src/serve.c b/src/serve.c
index 00d51b5..a856bc2 100644
--- a/src/serve.c
+++ b/src/serve.c
@@ -1,9 +1,12 @@
 #include <assert.h>
+#include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
 #include "config.h"
 #include "gemini.h"
 #include "log.h"
@@ -13,11 +16,11 @@
 
 void
 client_submit_response(struct gmnisrv_client *client,
-	enum gemini_status status, const char *meta, int bodyfd)
+	enum gemini_status status, const char *meta, FILE *body)
 {
 	client->status = status;
 	client->meta = strdup(meta);
-	client->bodyfd = bodyfd;
+	client->body = body;
 	client->pollfd->events = POLLOUT;
 }
 
@@ -26,7 +29,92 @@ client_oom(struct gmnisrv_client *client)
 {
 	const char *error = "Out of memory";
 	client_submit_response(client,
-		GEMINI_STATUS_TEMPORARY_FAILURE, error, -1);
+		GEMINI_STATUS_TEMPORARY_FAILURE, error, NULL);
+}
+
+static int
+namecmp(const void *p1, const void *p2)
+{
+	return strcmp(*(char *const *)p1, *(char *const *)p2);
+}
+
+void
+serve_autoindex(struct gmnisrv_client *client, const char *path)
+{
+	size_t bufsz = 0;
+	size_t nameln = 0, namesz = 1024;
+	char **names = calloc(namesz, sizeof(char *));
+
+	DIR *dirp = opendir(path);
+	if (!dirp) {
+		goto internal_error;
+	}
+
+	bufsz += snprintf(NULL, 0, "# Index of %s\n\n", client->path);
+
+	struct dirent *ent;
+	errno = 0;
+	while ((ent = readdir(dirp)) != NULL) {
+		char fpath[PATH_MAX + 1];
+		strcpy(fpath, path);
+		strncat(fpath, ent->d_name, sizeof(fpath));
+
+		struct stat st;
+		if (stat(fpath, &st) != 0) {
+			goto internal_error;
+		}
+
+		if ((S_ISREG(st.st_mode) || S_ISLNK(st.st_mode) || S_ISDIR(st.st_mode))
+				&& ent->d_name[0] != '.') {
+			if (nameln >= namesz) {
+				char **new = realloc(names, namesz * 2);
+				if (!new) {
+					goto internal_error;
+				}
+				namesz *= 2;
+				names = new;
+			}
+			names[nameln++] = strdup(ent->d_name);
+			bufsz += snprintf(NULL, 0, "=> %s\n", ent->d_name);
+		}
+
+		errno = 0;
+	}
+	if (errno != 0) {
+		goto internal_error;
+	}
+
+	qsort(names, nameln, sizeof(names[0]), namecmp);
+
+	FILE *buf = fmemopen(NULL, bufsz, "w+");
+	if (!buf) {
+		goto internal_error;
+	}
+	int r;
+	r = fprintf(buf, "# Index of %s\n\n", client->path);
+	assert(r > 0);
+	for (size_t i = 0; i < nameln; ++i) {
+		r = fprintf(buf, "=> %s\n", names[i]);
+		assert(r > 0);
+	}
+	r = fseek(buf, 0, SEEK_SET);
+	assert(r == 0);
+	client_submit_response(client, GEMINI_STATUS_SUCCESS,
+		"text/gemini", buf);
+
+exit:
+	closedir(dirp);
+	for (size_t i = 0; i < nameln; ++i) {
+		free(names[i]);
+	}
+	free(names);
+	return;
+
+internal_error:
+	server_error("Error reading %s: %s", path, strerror(errno));
+	client_submit_response(client, GEMINI_STATUS_PERMANENT_FAILURE,
+		"Internal server error", NULL);
+	goto exit;
 }
 
 void
@@ -40,32 +128,69 @@ serve_request(struct gmnisrv_client *client)
 	int n = snprintf(path, sizeof(path), "%s%s", host->root, client->path);
 	if ((size_t)n >= sizeof(path)) {
 		client_submit_response(client, GEMINI_STATUS_PERMANENT_FAILURE,
-			"Request path exceeds PATH_MAX", -1);
+			"Request path exceeds PATH_MAX", NULL);
 		return;
 	}
 
-	if (path[strlen(path) - 1] == '/') {
-		// TODO: Let user configure index file name?
-		strncat(path, "index.gmi", sizeof(path) - 1);
+	int nlinks = 0;
+	struct stat st;
+	while (true) {
+		if ((n = stat(path, &st)) != 0) {
+			client_submit_response(client,
+				GEMINI_STATUS_NOT_FOUND, "Not found", NULL);
+			return;
+		}
+
+		if (S_ISDIR(st.st_mode)) {
+			if (host->autoindex) {
+				serve_autoindex(client, path);
+				return;
+			} else {
+				strncat(path,
+					host->index ? host->index : "index.gmi",
+					sizeof(path) - 1);
+			}
+		} else if (S_ISLNK(st.st_mode)) {
+			++nlinks;
+			if (nlinks > 3) {
+				server_error("Maximum redirects exceeded for %s",
+					client->path);
+				client_submit_response(client,
+					GEMINI_STATUS_NOT_FOUND,
+					"Not found", NULL);
+				return;
+			}
+			char path2[PATH_MAX + 1];
+			ssize_t s = readlink(path, path2, sizeof(path2));
+			assert(s != -1);
+			strcpy(path, path2);
+		} else if (S_ISREG(st.st_mode)) {
+			break;
+		} else {
+			// Don't serve special files
+			client_submit_response(client,
+				GEMINI_STATUS_NOT_FOUND, "Not found", NULL);
+			return;
+		}
 	}
 
-	int fd = open(path, O_RDONLY);
-	if (fd == -1) {
+	FILE *body = fopen(path, "r");
+	if (!body) {
 		if (errno == ENOENT) {
-			client_submit_response(client, GEMINI_STATUS_NOT_FOUND,
-				"Not found", -1);
+			client_submit_response(client,
+				GEMINI_STATUS_NOT_FOUND, "Not found", NULL);
 			return;
 		} else {
 			client_error(&client->addr, "error opening %s: %s",
 					path, strerror(errno));
 			client_submit_response(client, GEMINI_STATUS_PERMANENT_FAILURE,
-				"Internal server error", -1);
+				"Internal server error", NULL);
 			return;
 		}
 	}
 
 	const char *meta = gmnisrv_mimetype_for_path(path);
-	client_submit_response(client, GEMINI_STATUS_SUCCESS, meta, fd);
+	client_submit_response(client, GEMINI_STATUS_SUCCESS, meta, body);
 }
 
 bool
@@ -79,7 +204,7 @@ request_validate(struct gmnisrv_client *client, char **path)
 	if (curl_url_set(url, CURLUPART_URL, client->buf, 0) != CURLUE_OK) {
 		const char *error = "Protocol error: invalid URL";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		goto exit;
 	}
 
@@ -87,13 +212,13 @@ request_validate(struct gmnisrv_client *client, char **path)
 	if (curl_url_get(url, CURLUPART_SCHEME, &part, 0) != CURLUE_OK) {
 		const char *error = "Protocol error: invalid URL (expected scheme)";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		goto exit;
 	} else if (strcmp(part, "gemini") != 0) {
 		free(part);
 		const char *error = "Refusing proxy to non-gemini URL";
 		client_submit_response(client,
-			GEMINI_STATUS_PROXY_REQUEST_REFUSED, error, -1);
+			GEMINI_STATUS_PROXY_REQUEST_REFUSED, error, NULL);
 		goto exit;
 	}
 	free(part);
@@ -101,13 +226,13 @@ request_validate(struct gmnisrv_client *client, char **path)
 	if (curl_url_get(url, CURLUPART_HOST, &part, 0) != CURLUE_OK) {
 		const char *error = "Protocol error: invalid URL (expected host)";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		goto exit;
 	} else if (strcmp(part, client->host->hostname) != 0) {
 		free(part);
 		const char *error = "Protocol error: hostname does not match SNI";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		goto exit;
 	}
 	free(part);
@@ -115,7 +240,7 @@ request_validate(struct gmnisrv_client *client, char **path)
 	if (curl_url_get(url, CURLUPART_PATH, &part, 0) != CURLUE_OK) {
 		const char *error = "Protocol error: invalid URL (expected path)";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		goto exit;
 	}
 	// NOTE: curl_url_set(..., CURLUPART_URL, ..., 0) will consoldate .. and
diff --git a/src/server.c b/src/server.c
index e69e381..c818fbd 100644
--- a/src/server.c
+++ b/src/server.c
@@ -150,7 +150,6 @@ accept_client(struct gmnisrv_server *server, int fd)
 	client->pollfd = pollfd;
 	client->addrlen = addrlen;
 	client->server = server;
-	client->bodyfd = -1;
 	clock_gettime(CLOCK_MONOTONIC, &client->ctime);
 	memcpy(&client->addr, &addr, sizeof(addr));
 
@@ -240,7 +239,7 @@ client_readable(struct gmnisrv_server *server, struct gmnisrv_client *client)
 	if (!client->host) {
 		const char *error = "This server requires clients to support the TLS SNI (server name identification) extension";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		return;
 	}
 
@@ -261,7 +260,7 @@ client_readable(struct gmnisrv_server *server, struct gmnisrv_client *client)
 	if (!newline) {
 		const char *error = "Protocol error: malformed request";
 		client_submit_response(client,
-			GEMINI_STATUS_BAD_REQUEST, error, -1);
+			GEMINI_STATUS_BAD_REQUEST, error, NULL);
 		return;
 	}
 	*newline = 0;
@@ -304,7 +303,7 @@ client_writable(struct gmnisrv_server *server, struct gmnisrv_client *client)
 		}
 		client->bufix += r;
 		if (client->bufix >= client->bufln) {
-			if (client->bodyfd == -1) {
+			if (!client->body) {
 				disconnect_client(server, client);
 			} else {
 				client->state = RESPOND_BODY;
@@ -315,8 +314,8 @@ client_writable(struct gmnisrv_server *server, struct gmnisrv_client *client)
 		break;
 	case RESPOND_BODY:
 		if (client->bufix >= client->bufln) {
-			n = read(client->bodyfd,
-				client->buf, sizeof(client->buf));
+			n = fread(client->buf, 1,
+				sizeof(client->buf), client->body);
 			if (n == -1) {
 				client_error(&client->addr,
 					"Error reading response body: %s",