commit 3e4749f7f9b6c37c1870ed3c0561083de17f2197
from: Omar Polo <op@omarpolo.com>
date: Fri Oct 02 17:39:00 2020 UTC

initial commit

commit - /dev/null
commit + 3e4749f7f9b6c37c1870ed3c0561083de17f2197
blob - /dev/null
blob + 9b1c514b6ac3057e90a07914b91c47799f6468fb (mode 644)
--- /dev/null
+++ .gitignore
@@ -0,0 +1,6 @@
+cert.pem
+key.pem
+TAGS
+gmid
+*.o
+docs
blob - /dev/null
blob + 76256b7dcf84f8002c97d62473907654109b4556 (mode 644)
--- /dev/null
+++ INSTALL.gmi
@@ -0,0 +1,15 @@
+# Installing gmid
+
+## dependencies
+
+gmid depends on libtls and a C compiler.  It's reported to compile with gcc 4.2, so it should work pretty everywhere now.
+
+The compilation is as easy as
+
+```
+make
+```
+
+Note that there isn't an install target yet.
+
+If you're a packager, don't forget to install also the manpage gmid.1
blob - /dev/null
blob + 9f005bf026bc8d76f5ee1f8b7bfa68270a41bab0 (mode 644)
--- /dev/null
+++ Makefile
@@ -0,0 +1,19 @@
+CC =		cc
+CFLAGS =	-Wall -Wextra -g
+LDFLAGS =	-ltls
+
+.PHONY: all clean
+
+all: gmid TAGS README.md
+
+gmid: gmid.o
+	${CC} gmid.o -o gmid ${LDFLAGS}
+
+TAGS: gmid.c
+	-etags gmid.c
+
+README.md: gmid.1
+	mandoc -Tmarkdown gmid.1 | sed -e '1d' -e '$d' > README.md
+
+clean:
+	rm -f gmid.o gmid
blob - /dev/null
blob + 0b85f411030f07f17b20a3b88b7f3c1a2297d9b2 (mode 644)
--- /dev/null
+++ README.md
@@ -0,0 +1,90 @@
+
+# NAME
+
+**gmid** - dead simple gemini server
+
+# SYNOPSIS
+
+**gmid**
+\[**-h**]
+\[**-c**&nbsp;*cert.pem*]
+\[**-d**&nbsp;*docs*]
+\[**-k**&nbsp;*key.pem*]
+
+# DESCRIPTION
+
+**gmid**
+is a very simple and minimal gemini server.
+It only supports serving static content, and strive to be as simple as
+possible.
+
+**gmid**
+will strip any sequence of
+*../*
+or trailing
+*..*
+in the requests made by clients, so it's impossible to serve content
+outside the
+*docs*
+directory by mistake.
+Furthermore, on OpenBSD,
+pledge(3)
+and
+unveil(3)
+are used to ensure that
+**gmid**
+dosen't do anything else than read files from the given directory and
+accept network connections.
+
+It should be noted that
+**gmid**
+is very simple in its implementation, and so it may not be appropriate
+for serving site with lots of users.
+After all, the code is single threaded and use a single process.
+
+The options are as follows:
+
+**-c** *cert.pem*
+
+> The certificate to use, by default is
+> *cert.pem*
+
+**-d** *docs*
+
+> The root directory to serve.
+> **gmid**
+> won't serve any file that is outside that directory.
+
+**-h**
+
+> Print the usage and exit
+
+**-k** *key.pem*
+
+> The key for the certificate, by default is
+> *key.pem*
+
+# EXAMPLES
+
+To quickly getting started
+
+	$ # generate a cert and a key
+	$ openssl req -x509 -newkey rsa:4096 -keyout key.pem \
+	        -out cert.pem -days 365 -nodes
+	$ mkdir docs
+	$ cat <<EOF > docs/index.gmi
+	# Hello world
+	test paragraph...
+	EOF
+	$ gmid -c cert.pem -k key.pem -d docs
+
+	now you can visit gemini://localhost/ with your preferred gemini client.
+
+# CAVEATS
+
+*	it doesn't support virtual host: the host part of the request URL is
+	completely ignored.
+
+*	it doesn't fork in the background or anything like that.
+
+OpenBSD 6.8 - October 2, 2020
blob - /dev/null
blob + 9f9dcc991d8bfa91f3da86d9634bb302097e3b4c (mode 644)
--- /dev/null
+++ gmid.1
@@ -0,0 +1,95 @@
+.\" Copyright (c) 2020 Omar Polo <op@omarpolo.com>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.Dd $Mdocdate: October 2 2020$
+.Dt GMIND 1
+.Os
+.Sh NAME
+.Nm gmid
+.Nd dead simple gemini server
+.Sh SYNOPSIS
+.Nm
+.Bk -words
+.Op Fl h
+.Op Fl c Ar cert.pem
+.Op Fl d Ar docs
+.Op Fl k Ar key.pem
+.Ek
+.Sh DESCRIPTION
+.Nm
+is a very simple and minimal gemini server.
+It only supports serving static content, and strive to be as simple as
+possible.
+.Pp
+.Nm
+will strip any sequence of
+.Pa ../
+or trailing
+.Pa ..
+in the requests made by clients, so it's impossible to serve content
+outside the
+.Pa docs
+directory by mistake.
+Furthermore, on OpenBSD,
+.Xr pledge 3
+and
+.Xr unveil 3
+are used to ensure that
+.Nm
+dosen't do anything else than read files from the given directory and
+accept network connections.
+.Pp
+It should be noted that
+.Nm
+is very simple in its implementation, and so it may not be appropriate
+for serving site with lots of users.
+After all, the code is single threaded and use a single process.
+.Pp
+The options are as follows:
+.Bl -tag -width 12m
+.It Fl c Ar cert.pem
+The certificate to use, by default is
+.Pa cert.pem
+.It Fl d Ar docs
+The root directory to serve.
+.Nm
+won't serve any file that is outside that directory.
+.It Fl h
+Print the usage and exit
+.It Fl k Ar key.pem
+The key for the certificate, by default is
+.Pa key.pem
+.El
+.Sh EXAMPLES
+To quickly getting started
+.Bd -literal -indent
+$ # generate a cert and a key
+$ openssl req -x509 -newkey rsa:4096 -keyout key.pem \\
+        -out cert.pem -days 365 -nodes
+$ mkdir docs
+$ cat <<EOF > docs/index.gmi
+# Hello world
+test paragraph...
+EOF
+$ gmid -c cert.pem -k key.pem -d docs
+.El
+.Pp
+now you can visit gemini://localhost/ with your preferred gemini client.
+.Sh CAVEATS
+.Bl -bullet
+.It
+it doesn't support virtual host: the host part of the request URL is
+completely ignored.
+.It
+it doesn't fork in the background or anything like that.
+.El
blob - /dev/null
blob + b7db8b9d8d61e6d11bbdc113c406ad21f1dba133 (mode 644)
--- /dev/null
+++ gmid.c
@@ -0,0 +1,431 @@
+/*
+ * Copyright (c) 2020 Omar Polo <op@omarpolo.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+
+#include <netinet/in.h>
+
+#include <assert.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <tls.h>
+#include <unistd.h>
+
+#ifndef __OpenBSD__
+# define pledge(a, b) 0
+# define unveil(a, b) 0
+#endif /* __OpenBSD__ */
+
+#define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
+
+/* large enough to hold a copy of a gemini URL and still have room */
+#define PATHBUF (2048)
+
+#define FILEBUF 1024
+
+#define SUCCESS		20
+#define NOT_FOUND	51
+#define BAD_REQUEST	59
+
+int dirfd;
+
+char *
+url_after_proto(char *url)
+{
+	char *s;
+	const char *proto = "gemini";
+	const char *marker = "://";
+
+	if ((s = strstr(url, marker)) == NULL)
+		return url;
+
+	/* not a gemini:// URL */
+
+	if (s - strlen(proto) < url)
+		return NULL;
+	/* TODO: */
+	/* if (strcmp(s - strlen(proto), proto)) */
+	/* 	return NULL; */
+
+	/* a valid gemini:// URL */
+	return s + strlen(marker);
+}
+
+char *
+url_start_of_request(char *url)
+{
+	char *s, *t;
+
+	if ((s = url_after_proto(url)) == NULL)
+		return NULL;
+
+	if ((t = strstr(s, "/")) == NULL)
+		return s + strlen(s);
+	return t;
+}
+
+int
+url_trim(char *url)
+{
+	const char *e = "\r\n";
+	char *s;
+
+	if ((s = strstr(url, e)) == NULL)
+		return 0;
+	s[0] = '\0';
+	s[1] = '\0';
+
+	if (s[2] != '\0') {
+		fprintf(stderr, "last byte of request isn't NULL\n");
+		return 0;
+	}
+
+	return 1;
+}
+
+void
+adjust_path(char *path)
+{
+	char *s;
+	size_t len;
+
+        /* /.. -> / */
+	len = strlen(path);
+	if (len >= 3) {
+		if (!strcmp(&path[len-3], "/..")) {
+			path[len-2] = '\0';
+		}
+	}
+
+	/* if the path is only `..` trim out and exit */
+	if (!strcmp(path, "..")) {
+		path[0] = '\0';
+		return;
+	}
+
+	/* remove every ../ in the path */
+	while (1) {
+		if ((s = strstr(path, "../")) == NULL)
+			return;
+		memmove(s - 3, s, strlen(s)+1);	/* copy also the \0 */
+	}
+}
+
+int
+path_isdir(char *path)
+{
+	size_t len;
+
+	if (*path == '\0')
+		return 1;
+
+	len = strlen(path);
+
+	/* len >= 1 */
+	if (path[len-1] == '/')
+		return 1;
+
+	return 0;
+}
+
+void
+start_reply(struct tls *ctx, int code, const char *reason)
+{
+	char buf[1030] = {0}; 	/* status + ' ' + max reply len + \r\n\0 */
+	int len;
+
+	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
+	assert(len < (int)sizeof(buf));
+	tls_write(ctx, buf, len);
+}
+
+int
+isdir(int fd)
+{
+	struct stat sb;
+
+	if (fstat(fd, &sb) == -1) {
+		warn("fstat");
+		return 1; 	/* we'll fail later on anyway */
+	}
+
+	return S_ISDIR(sb.st_mode);
+}
+
+void		 senddir(char*, struct tls*);
+
+void
+sendfile(char *path, struct tls *ctx)
+{
+	int fd;
+	char fpath[PATHBUF];
+	char buf[FILEBUF];
+	size_t i;
+	ssize_t t, w;
+
+	bzero(fpath, sizeof(fpath));
+
+	if (*path != '.')
+		strlcpy(fpath, ".", PATHBUF);
+	
+	strlcat(fpath, path, PATHBUF);
+
+	if ((fd = openat(dirfd, fpath, O_RDONLY | O_NOFOLLOW)) == -1) {
+		warn("open: %s", fpath);
+		start_reply(ctx, NOT_FOUND, "not found");
+		return;
+	}
+
+	if (isdir(fd)) {
+		warnx("%s is a directory, trying %s/index.gmi", fpath, fpath);
+		close(fd);
+		senddir(fpath, ctx);
+		return;
+	}
+
+	/* assume it's a text/gemini file */
+	start_reply(ctx, SUCCESS, "text/gemini");
+
+        while (1) {
+		if ((w = read(fd, buf, sizeof(buf))) == -1) {
+			warn("read: %s", fpath);
+			goto exit;
+		}
+
+		if (w == 0)
+			break;
+
+		t = w;
+		i = 0;
+
+		while (w > 0) {
+			if ((t = tls_write(ctx, buf + i, w)) == -1) {
+				warnx("tls_write (path=%s) : %s",
+				    fpath,
+				    tls_error(ctx));
+				goto exit;
+			}
+			w -= t;
+			i += t;
+		}
+	}
+
+exit:
+	close(fd);
+}
+
+void
+senddir(char *path, struct tls *ctx)
+{
+	char fpath[PATHBUF];
+	size_t len;
+
+	bzero(fpath, PATHBUF);
+
+	if (*path != '.')
+		fpath[0] = '.';
+
+	/* this cannot fail since sizeof(fpath) > maxlen of path */
+	strlcat(fpath, path, PATHBUF);
+	len = strlen(fpath);
+
+	/* add a trailing / in case. */
+	if (fpath[len-1] != '/') {
+		fpath[len] = '/';
+	}
+
+	strlcat(fpath, "index.gmi", sizeof(fpath));
+
+	sendfile(fpath, ctx);
+}
+
+void
+handle(char *url, struct tls *ctx)
+{
+	char *path;
+
+	if (!url_trim(url)) {
+		start_reply(ctx, BAD_REQUEST, "bad request");
+		return;
+	}
+
+	if ((path = url_start_of_request(url)) == NULL)
+		return;
+
+	adjust_path(path);
+
+	fprintf(stderr, "requested path: %s\n", path);
+
+	if (path_isdir(path))
+		senddir(path, ctx);
+	else
+		sendfile(path, ctx);
+}
+
+int
+make_socket(int port)
+{
+	int sock, v;
+	struct sockaddr_in addr;
+
+	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
+                err(1, "socket");
+
+	v = 1;
+	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
+		err(1, "setsockopt(SO_REUSEADDR)");
+
+	v = 1;
+	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
+		err(1, "setsockopt(SO_REUSEPORT)");
+
+	bzero(&addr, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(port);
+	addr.sin_addr.s_addr = INADDR_ANY;
+
+	if (bind(sock, (struct sockaddr*)&addr, sizeof(addr)) == -1)
+                err(1, "bind");
+
+	if (listen(sock, 16) == -1)
+                err(1, "listen");
+
+	return sock;
+}
+
+void
+loop(struct tls *ctx, int sock)
+{
+	int fd;
+	struct sockaddr_in client;
+	socklen_t len;
+	struct tls *clientctx;
+	char buf[GEMINI_URL_LEN];
+	ssize_t r;
+
+	for (;;) {
+		len = sizeof(client);
+		if ((fd = accept(sock, (struct sockaddr*)&client, &len)) == -1)
+                        err(1, "accept");
+
+		if (tls_accept_socket(ctx, &clientctx, fd) == -1) {
+			warnx("tls_accept_socket: %s", tls_error(ctx));
+			continue;
+		}
+
+		bzero(buf, GEMINI_URL_LEN);
+		if ((r = tls_read(clientctx, buf, sizeof(buf)-1)) == -1) {
+			warnx("tls_read: %s", tls_error(clientctx));
+			goto clienterr;
+		}
+
+		handle(buf, clientctx);
+
+	clienterr:
+		if (tls_close(clientctx) == -1)
+			warn("tls_close: client");
+		tls_free(clientctx);
+		close(fd);
+	}
+}
+
+void
+usage(const char *me)
+{
+	fprintf(stderr,
+	    "USAGE: %s [-h] [-c cert.pem] [-d docs] [-k key.pem]\n",
+	    me);
+}
+
+int
+main(int argc, char **argv)
+{
+	const char *cert = "cert.pem", *key = "key.pem", *dir = "docs";
+	struct tls *ctx = NULL;
+	struct tls_config *conf;
+	void *m;
+	size_t mlen;
+	int sock, ch;
+
+	while ((ch = getopt(argc, argv, "c:d:hk:")) != -1) {
+		switch (ch) {
+		case 'c':
+			cert = optarg;
+			break;
+
+		case 'd':
+			dir = optarg;
+			break;
+
+		case 'h':
+			usage(*argv);
+			return 0;
+
+		case 'k':
+			key = optarg;
+			break;
+
+		default:
+			usage(*argv);
+			return 1;
+		}
+	}
+
+	if ((conf = tls_config_new()) == NULL)
+		err(1, "tls_config_new");
+
+	if ((m = tls_load_file(cert, &mlen, NULL)) == NULL)
+		err(1, "tls_load_file: %s", cert);
+	if (tls_config_set_cert_mem(conf, m, mlen) == -1)
+		err(1, "tls_config_set_cert_mem: server certificate");
+
+	if ((m = tls_load_file(key, &mlen, NULL)) == NULL)
+		err(1, "tls_load_file: %s", key);
+	if (tls_config_set_key_mem(conf, m, mlen) == -1)
+		err(1, "tls_config_set_cert_mem: server key");
+
+	if ((ctx = tls_server()) == NULL)
+		err(1, "tls_server");
+
+	if (tls_configure(ctx, conf) == -1)
+		errx(1, "tls_configure: %s", tls_error(ctx));
+
+	sock = make_socket(1965);
+
+	if ((dirfd = open(dir, O_RDONLY | O_DIRECTORY)) == -1)
+		err(1, "open: %s", dir);
+
+	if (unveil(dir, "r") == -1)
+		err(1, "unveil");
+
+	if (pledge("stdio rpath inet", "") == -1)
+		err(1, "pledge");
+
+	loop(ctx, sock);
+
+	if (1) {
+		printf("why im I here?\n");
+		abort();
+	}
+
+	close(sock);
+	tls_free(ctx);
+	tls_config_free(conf);
+}