michael@0: /*
michael@0:   A trivial static http webserver using Libevent's evhttp.
michael@0: 
michael@0:   This is not the best code in the world, and it does some fairly stupid stuff
michael@0:   that you would never want to do in a production webserver. Caveat hackor!
michael@0: 
michael@0:  */
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include <string.h>
michael@0: 
michael@0: #include <sys/types.h>
michael@0: #include <sys/stat.h>
michael@0: 
michael@0: #ifdef WIN32
michael@0: #include <winsock2.h>
michael@0: #include <ws2tcpip.h>
michael@0: #include <windows.h>
michael@0: #include <io.h>
michael@0: #include <fcntl.h>
michael@0: #ifndef S_ISDIR
michael@0: #define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
michael@0: #endif
michael@0: #else
michael@0: #include <sys/stat.h>
michael@0: #include <sys/socket.h>
michael@0: #include <signal.h>
michael@0: #include <fcntl.h>
michael@0: #include <unistd.h>
michael@0: #include <dirent.h>
michael@0: #endif
michael@0: 
michael@0: #include <event2/event.h>
michael@0: #include <event2/http.h>
michael@0: #include <event2/buffer.h>
michael@0: #include <event2/util.h>
michael@0: #include <event2/keyvalq_struct.h>
michael@0: 
michael@0: #ifdef _EVENT_HAVE_NETINET_IN_H
michael@0: #include <netinet/in.h>
michael@0: # ifdef _XOPEN_SOURCE_EXTENDED
michael@0: #  include <arpa/inet.h>
michael@0: # endif
michael@0: #endif
michael@0: 
michael@0: /* Compatibility for possible missing IPv6 declarations */
michael@0: #include "../util-internal.h"
michael@0: 
michael@0: #ifdef WIN32
michael@0: #define stat _stat
michael@0: #define fstat _fstat
michael@0: #define open _open
michael@0: #define close _close
michael@0: #define O_RDONLY _O_RDONLY
michael@0: #endif
michael@0: 
michael@0: char uri_root[512];
michael@0: 
michael@0: static const struct table_entry {
michael@0: 	const char *extension;
michael@0: 	const char *content_type;
michael@0: } content_type_table[] = {
michael@0: 	{ "txt", "text/plain" },
michael@0: 	{ "c", "text/plain" },
michael@0: 	{ "h", "text/plain" },
michael@0: 	{ "html", "text/html" },
michael@0: 	{ "htm", "text/htm" },
michael@0: 	{ "css", "text/css" },
michael@0: 	{ "gif", "image/gif" },
michael@0: 	{ "jpg", "image/jpeg" },
michael@0: 	{ "jpeg", "image/jpeg" },
michael@0: 	{ "png", "image/png" },
michael@0: 	{ "pdf", "application/pdf" },
michael@0: 	{ "ps", "application/postsript" },
michael@0: 	{ NULL, NULL },
michael@0: };
michael@0: 
michael@0: /* Try to guess a good content-type for 'path' */
michael@0: static const char *
michael@0: guess_content_type(const char *path)
michael@0: {
michael@0: 	const char *last_period, *extension;
michael@0: 	const struct table_entry *ent;
michael@0: 	last_period = strrchr(path, '.');
michael@0: 	if (!last_period || strchr(last_period, '/'))
michael@0: 		goto not_found; /* no exension */
michael@0: 	extension = last_period + 1;
michael@0: 	for (ent = &content_type_table[0]; ent->extension; ++ent) {
michael@0: 		if (!evutil_ascii_strcasecmp(ent->extension, extension))
michael@0: 			return ent->content_type;
michael@0: 	}
michael@0: 
michael@0: not_found:
michael@0: 	return "application/misc";
michael@0: }
michael@0: 
michael@0: /* Callback used for the /dump URI, and for every non-GET request:
michael@0:  * dumps all information to stdout and gives back a trivial 200 ok */
michael@0: static void
michael@0: dump_request_cb(struct evhttp_request *req, void *arg)
michael@0: {
michael@0: 	const char *cmdtype;
michael@0: 	struct evkeyvalq *headers;
michael@0: 	struct evkeyval *header;
michael@0: 	struct evbuffer *buf;
michael@0: 
michael@0: 	switch (evhttp_request_get_command(req)) {
michael@0: 	case EVHTTP_REQ_GET: cmdtype = "GET"; break;
michael@0: 	case EVHTTP_REQ_POST: cmdtype = "POST"; break;
michael@0: 	case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break;
michael@0: 	case EVHTTP_REQ_PUT: cmdtype = "PUT"; break;
michael@0: 	case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break;
michael@0: 	case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break;
michael@0: 	case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break;
michael@0: 	case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break;
michael@0: 	case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break;
michael@0: 	default: cmdtype = "unknown"; break;
michael@0: 	}
michael@0: 
michael@0: 	printf("Received a %s request for %s\nHeaders:\n",
michael@0: 	    cmdtype, evhttp_request_get_uri(req));
michael@0: 
michael@0: 	headers = evhttp_request_get_input_headers(req);
michael@0: 	for (header = headers->tqh_first; header;
michael@0: 	    header = header->next.tqe_next) {
michael@0: 		printf("  %s: %s\n", header->key, header->value);
michael@0: 	}
michael@0: 
michael@0: 	buf = evhttp_request_get_input_buffer(req);
michael@0: 	puts("Input data: <<<");
michael@0: 	while (evbuffer_get_length(buf)) {
michael@0: 		int n;
michael@0: 		char cbuf[128];
michael@0: 		n = evbuffer_remove(buf, cbuf, sizeof(buf)-1);
michael@0: 		if (n > 0)
michael@0: 			(void) fwrite(cbuf, 1, n, stdout);
michael@0: 	}
michael@0: 	puts(">>>");
michael@0: 
michael@0: 	evhttp_send_reply(req, 200, "OK", NULL);
michael@0: }
michael@0: 
michael@0: /* This callback gets invoked when we get any http request that doesn't match
michael@0:  * any other callback.  Like any evhttp server callback, it has a simple job:
michael@0:  * it must eventually call evhttp_send_error() or evhttp_send_reply().
michael@0:  */
michael@0: static void
michael@0: send_document_cb(struct evhttp_request *req, void *arg)
michael@0: {
michael@0: 	struct evbuffer *evb = NULL;
michael@0: 	const char *docroot = arg;
michael@0: 	const char *uri = evhttp_request_get_uri(req);
michael@0: 	struct evhttp_uri *decoded = NULL;
michael@0: 	const char *path;
michael@0: 	char *decoded_path;
michael@0: 	char *whole_path = NULL;
michael@0: 	size_t len;
michael@0: 	int fd = -1;
michael@0: 	struct stat st;
michael@0: 
michael@0: 	if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) {
michael@0: 		dump_request_cb(req, arg);
michael@0: 		return;
michael@0: 	}
michael@0: 
michael@0: 	printf("Got a GET request for <%s>\n",  uri);
michael@0: 
michael@0: 	/* Decode the URI */
michael@0: 	decoded = evhttp_uri_parse(uri);
michael@0: 	if (!decoded) {
michael@0: 		printf("It's not a good URI. Sending BADREQUEST\n");
michael@0: 		evhttp_send_error(req, HTTP_BADREQUEST, 0);
michael@0: 		return;
michael@0: 	}
michael@0: 
michael@0: 	/* Let's see what path the user asked for. */
michael@0: 	path = evhttp_uri_get_path(decoded);
michael@0: 	if (!path) path = "/";
michael@0: 
michael@0: 	/* We need to decode it, to see what path the user really wanted. */
michael@0: 	decoded_path = evhttp_uridecode(path, 0, NULL);
michael@0: 	if (decoded_path == NULL)
michael@0: 		goto err;
michael@0: 	/* Don't allow any ".."s in the path, to avoid exposing stuff outside
michael@0: 	 * of the docroot.  This test is both overzealous and underzealous:
michael@0: 	 * it forbids aceptable paths like "/this/one..here", but it doesn't
michael@0: 	 * do anything to prevent symlink following." */
michael@0: 	if (strstr(decoded_path, ".."))
michael@0: 		goto err;
michael@0: 
michael@0: 	len = strlen(decoded_path)+strlen(docroot)+2;
michael@0: 	if (!(whole_path = malloc(len))) {
michael@0: 		perror("malloc");
michael@0: 		goto err;
michael@0: 	}
michael@0: 	evutil_snprintf(whole_path, len, "%s/%s", docroot, decoded_path);
michael@0: 
michael@0: 	if (stat(whole_path, &st)<0) {
michael@0: 		goto err;
michael@0: 	}
michael@0: 
michael@0: 	/* This holds the content we're sending. */
michael@0: 	evb = evbuffer_new();
michael@0: 
michael@0: 	if (S_ISDIR(st.st_mode)) {
michael@0: 		/* If it's a directory, read the comments and make a little
michael@0: 		 * index page */
michael@0: #ifdef WIN32
michael@0: 		HANDLE d;
michael@0: 		WIN32_FIND_DATAA ent;
michael@0: 		char *pattern;
michael@0: 		size_t dirlen;
michael@0: #else
michael@0: 		DIR *d;
michael@0: 		struct dirent *ent;
michael@0: #endif
michael@0: 		const char *trailing_slash = "";
michael@0: 
michael@0: 		if (!strlen(path) || path[strlen(path)-1] != '/')
michael@0: 			trailing_slash = "/";
michael@0: 
michael@0: #ifdef WIN32
michael@0: 		dirlen = strlen(whole_path);
michael@0: 		pattern = malloc(dirlen+3);
michael@0: 		memcpy(pattern, whole_path, dirlen);
michael@0: 		pattern[dirlen] = '\\';
michael@0: 		pattern[dirlen+1] = '*';
michael@0: 		pattern[dirlen+2] = '\0';
michael@0: 		d = FindFirstFileA(pattern, &ent);
michael@0: 		free(pattern);
michael@0: 		if (d == INVALID_HANDLE_VALUE)
michael@0: 			goto err;
michael@0: #else
michael@0: 		if (!(d = opendir(whole_path)))
michael@0: 			goto err;
michael@0: #endif
michael@0: 
michael@0: 		evbuffer_add_printf(evb, "<html>\n <head>\n"
michael@0: 		    "  <title>%s</title>\n"
michael@0: 		    "  <base href='%s%s%s'>\n"
michael@0: 		    " </head>\n"
michael@0: 		    " <body>\n"
michael@0: 		    "  <h1>%s</h1>\n"
michael@0: 		    "  <ul>\n",
michael@0: 		    decoded_path, /* XXX html-escape this. */
michael@0: 		    uri_root, path, /* XXX html-escape this? */
michael@0: 		    trailing_slash,
michael@0: 		    decoded_path /* XXX html-escape this */);
michael@0: #ifdef WIN32
michael@0: 		do {
michael@0: 			const char *name = ent.cFileName;
michael@0: #else
michael@0: 		while ((ent = readdir(d))) {
michael@0: 			const char *name = ent->d_name;
michael@0: #endif
michael@0: 			evbuffer_add_printf(evb,
michael@0: 			    "    <li><a href=\"%s\">%s</a>\n",
michael@0: 			    name, name);/* XXX escape this */
michael@0: #ifdef WIN32
michael@0: 		} while (FindNextFileA(d, &ent));
michael@0: #else
michael@0: 		}
michael@0: #endif
michael@0: 		evbuffer_add_printf(evb, "</ul></body></html>\n");
michael@0: #ifdef WIN32
michael@0: 		CloseHandle(d);
michael@0: #else
michael@0: 		closedir(d);
michael@0: #endif
michael@0: 		evhttp_add_header(evhttp_request_get_output_headers(req),
michael@0: 		    "Content-Type", "text/html");
michael@0: 	} else {
michael@0: 		/* Otherwise it's a file; add it to the buffer to get
michael@0: 		 * sent via sendfile */
michael@0: 		const char *type = guess_content_type(decoded_path);
michael@0: 		if ((fd = open(whole_path, O_RDONLY)) < 0) {
michael@0: 			perror("open");
michael@0: 			goto err;
michael@0: 		}
michael@0: 
michael@0: 		if (fstat(fd, &st)<0) {
michael@0: 			/* Make sure the length still matches, now that we
michael@0: 			 * opened the file :/ */
michael@0: 			perror("fstat");
michael@0: 			goto err;
michael@0: 		}
michael@0: 		evhttp_add_header(evhttp_request_get_output_headers(req),
michael@0: 		    "Content-Type", type);
michael@0: 		evbuffer_add_file(evb, fd, 0, st.st_size);
michael@0: 	}
michael@0: 
michael@0: 	evhttp_send_reply(req, 200, "OK", evb);
michael@0: 	goto done;
michael@0: err:
michael@0: 	evhttp_send_error(req, 404, "Document was not found");
michael@0: 	if (fd>=0)
michael@0: 		close(fd);
michael@0: done:
michael@0: 	if (decoded)
michael@0: 		evhttp_uri_free(decoded);
michael@0: 	if (decoded_path)
michael@0: 		free(decoded_path);
michael@0: 	if (whole_path)
michael@0: 		free(whole_path);
michael@0: 	if (evb)
michael@0: 		evbuffer_free(evb);
michael@0: }
michael@0: 
michael@0: static void
michael@0: syntax(void)
michael@0: {
michael@0: 	fprintf(stdout, "Syntax: http-server <docroot>\n");
michael@0: }
michael@0: 
michael@0: int
michael@0: main(int argc, char **argv)
michael@0: {
michael@0: 	struct event_base *base;
michael@0: 	struct evhttp *http;
michael@0: 	struct evhttp_bound_socket *handle;
michael@0: 
michael@0: 	unsigned short port = 0;
michael@0: #ifdef WIN32
michael@0: 	WSADATA WSAData;
michael@0: 	WSAStartup(0x101, &WSAData);
michael@0: #else
michael@0: 	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
michael@0: 		return (1);
michael@0: #endif
michael@0: 	if (argc < 2) {
michael@0: 		syntax();
michael@0: 		return 1;
michael@0: 	}
michael@0: 
michael@0: 	base = event_base_new();
michael@0: 	if (!base) {
michael@0: 		fprintf(stderr, "Couldn't create an event_base: exiting\n");
michael@0: 		return 1;
michael@0: 	}
michael@0: 
michael@0: 	/* Create a new evhttp object to handle requests. */
michael@0: 	http = evhttp_new(base);
michael@0: 	if (!http) {
michael@0: 		fprintf(stderr, "couldn't create evhttp. Exiting.\n");
michael@0: 		return 1;
michael@0: 	}
michael@0: 
michael@0: 	/* The /dump URI will dump all requests to stdout and say 200 ok. */
michael@0: 	evhttp_set_cb(http, "/dump", dump_request_cb, NULL);
michael@0: 
michael@0: 	/* We want to accept arbitrary requests, so we need to set a "generic"
michael@0: 	 * cb.  We can also add callbacks for specific paths. */
michael@0: 	evhttp_set_gencb(http, send_document_cb, argv[1]);
michael@0: 
michael@0: 	/* Now we tell the evhttp what port to listen on */
michael@0: 	handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", port);
michael@0: 	if (!handle) {
michael@0: 		fprintf(stderr, "couldn't bind to port %d. Exiting.\n",
michael@0: 		    (int)port);
michael@0: 		return 1;
michael@0: 	}
michael@0: 
michael@0: 	{
michael@0: 		/* Extract and display the address we're listening on. */
michael@0: 		struct sockaddr_storage ss;
michael@0: 		evutil_socket_t fd;
michael@0: 		ev_socklen_t socklen = sizeof(ss);
michael@0: 		char addrbuf[128];
michael@0: 		void *inaddr;
michael@0: 		const char *addr;
michael@0: 		int got_port = -1;
michael@0: 		fd = evhttp_bound_socket_get_fd(handle);
michael@0: 		memset(&ss, 0, sizeof(ss));
michael@0: 		if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) {
michael@0: 			perror("getsockname() failed");
michael@0: 			return 1;
michael@0: 		}
michael@0: 		if (ss.ss_family == AF_INET) {
michael@0: 			got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port);
michael@0: 			inaddr = &((struct sockaddr_in*)&ss)->sin_addr;
michael@0: 		} else if (ss.ss_family == AF_INET6) {
michael@0: 			got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port);
michael@0: 			inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr;
michael@0: 		} else {
michael@0: 			fprintf(stderr, "Weird address family %d\n",
michael@0: 			    ss.ss_family);
michael@0: 			return 1;
michael@0: 		}
michael@0: 		addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf,
michael@0: 		    sizeof(addrbuf));
michael@0: 		if (addr) {
michael@0: 			printf("Listening on %s:%d\n", addr, got_port);
michael@0: 			evutil_snprintf(uri_root, sizeof(uri_root),
michael@0: 			    "http://%s:%d",addr,got_port);
michael@0: 		} else {
michael@0: 			fprintf(stderr, "evutil_inet_ntop failed\n");
michael@0: 			return 1;
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	event_base_dispatch(base);
michael@0: 
michael@0: 	return 0;
michael@0: }