Add quick

5 files changed, 245 insertions, 1 deletions

diff --git a/bin/.gitignore b/bin/.gitignore
index 5f3bf0c7..a8d641b5 100644
--- a/bin/.gitignore
+++ b/bin/.gitignore
@@ -23,6 +23,7 @@ pbd
 pngo
 psf2png
 ptee
+quick
 relay
 scheme
 scheme.h
diff --git a/bin/Makefile b/bin/Makefile
index 9fe60278..f44d3026 100644
--- a/bin/Makefile
+++ b/bin/Makefile
@@ -25,6 +25,7 @@ BINS += pbd
 BINS += pngo
 BINS += psf2png
 BINS += ptee
+BINS += quick
 BINS += scheme
 BINS += shotty
 BINS += sup
diff --git a/bin/README.7 b/bin/README.7
index be4c6a31..6d4e4e8a 100644
--- a/bin/README.7
+++ b/bin/README.7
@@ -1,4 +1,4 @@
-.Dd September 22, 2021
+.Dd September 23, 2021
 .Dt BIN 7
 .Os "Causal Agency"
 .
@@ -56,6 +56,8 @@ PNG optimizer
 PSF2 to PNG renderer
 .It Xr ptee 1
 tee for PTYs
+.It Xr quick 1
+terrible HTTP/CGI server
 .It Xr relay 1
 IRC relay bot
 .It Xr scheme 1
diff --git a/bin/man1/quick.1 b/bin/man1/quick.1
new file mode 100644
index 00000000..96f1766a
--- /dev/null
+++ b/bin/man1/quick.1
@@ -0,0 +1,66 @@
+.Dd September 23, 2021
+.Dt QUICK 1
+.Os
+.
+.Sh NAME
+.Nm quick
+.Nd (and dirty) HTTP/CGI server
+.
+.Sh SYNOPSIS
+.Nm
+.Op Fl p Ar port
+.Ar script
+.Op Ar args ...
+.
+.Sh DESCRIPTION
+.Nm
+is a barely functional HTTP server
+for running CGI scripts.
+It listens only on localhost,
+on a randomly assigned port,
+unless
+.Fl p
+is used.
+The URL of the server
+is printed to standard output.
+.
+.Sh EXAMPLES
+.Dl quick cgit | xargs -n1 open
+.
+.Sh STANDARDS
+.Nm
+does
+.Em not
+implement the following:
+.Bl -item
+.It
+.Rs
+.%A T. Berners-Lee
+.%A R. Fielding
+.%A H. Frystyk
+.%A J. Gettys
+.%A J. Mogul
+.%T Hypertext Transfer Protocol -- HTTP/1.1
+.%R RFC 2068
+.%U https://tools.ietf.org/html/rfc2068
+.%D January 1997
+.Re
+.It
+.Rs
+.%A K. Coar
+.%A D. Robinson
+.%T The Common Gateway Interface (CGI) Version 1.1
+.%R RFC 3875
+.%U https://tools.ietf.org/html/rfc3875
+.%D October 2004
+.Re
+.El
+.
+.Sh CAVEATS
+Oh, so many.
+No error handling,
+no validation,
+no security.
+This is a local testing tool only.
+.Pp
+Every response is served as a 200 OK.
diff --git a/bin/quick.c b/bin/quick.c
new file mode 100644
index 00000000..150eaf62
--- /dev/null
+++ b/bin/quick.c
@@ -0,0 +1,174 @@
+/* Copyright (C) 2021  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <arpa/inet.h>
+#include <ctype.h>
+#include <err.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+static void request(int sock, char *argv[]) {
+	FILE *req = fdopen(dup(sock), "r");
+	if (!req) err(EX_OSERR, "fdopen");
+	fcntl(fileno(req), F_SETFD, FD_CLOEXEC);
+
+	size_t cap = 0;
+	char *buf = NULL;
+	ssize_t len = getline(&buf, &cap, req);
+	if (len < 0) goto close;
+
+	char *ptr = buf;
+	char *method = strsep(&ptr, " ");
+	char *query = strsep(&ptr, " ");
+	char *path = strsep(&query, "?");
+	char *proto = strsep(&ptr, "\r\n");
+	if (!method || !path || !proto) goto close;
+
+	setenv("REQUEST_METHOD", method, 1);
+	setenv("PATH_INFO", path, 1);
+	setenv("QUERY_STRING", (query ? query : ""), 1);
+	setenv("SERVER_PROTOCOL", proto, 1);
+	unsetenv("CONTENT_TYPE");
+	unsetenv("CONTENT_LENGTH");
+	unsetenv("HTTP_HOST");
+
+	size_t bodyLen = 0;
+	while (0 <= (len = getline(&buf, &cap, req))) {
+		if (len && buf[len-1] == '\n') buf[--len] = '\0';
+		if (len && buf[len-1] == '\r') buf[--len] = '\0';
+		if (!len) break;
+
+		char *value = buf;
+		char *header = strsep(&value, ":");
+		if (!header || !value++) goto close;
+
+		if (!strcasecmp(header, "Content-Type")) {
+			setenv("CONTENT_TYPE", value, 1);
+		} else if (!strcasecmp(header, "Content-Length")) {
+			bodyLen = strtoull(value, NULL, 10);
+			setenv("CONTENT_LENGTH", value, 1);
+		} else {
+			char buf[256];
+			for (char *ch = header; *ch; ++ch) {
+				*ch = (*ch == '-' ? '_' : toupper(*ch));
+			}
+			snprintf(buf, sizeof(buf), "HTTP_%s", header);
+			setenv(buf, value, 1);
+		}
+	}
+
+	int rw[2];
+	int error = pipe(rw);
+	if (error) err(EX_OSERR, "pipe");
+	fcntl(rw[0], F_SETFD, FD_CLOEXEC);
+	fcntl(rw[1], F_SETFD, FD_CLOEXEC);
+
+	dprintf(sock, "HTTP/1.1 200 OK\nConnection: close\n");
+	pid_t pid = fork();
+	if (pid < 0) err(EX_OSERR, "fork");
+	if (!pid) {
+		dup2(rw[0], STDIN_FILENO);
+		dup2(sock, STDOUT_FILENO);
+		execv(argv[0], argv);
+		warn("%s", argv[0]);
+		_exit(127);
+	}
+
+	close(rw[0]);
+	char body[4096];
+	while (bodyLen) {
+		size_t cap = (bodyLen < sizeof(body) ? bodyLen : sizeof(body));
+		size_t len = fread(&body, 1, cap, req);
+		if (!len) break;
+		write(rw[1], body, len);
+		bodyLen -= len;
+	}
+	close(rw[1]);
+
+	int status;
+	pid = wait(&status);
+	if (pid < 0) err(EX_OSERR, "wait");
+	if (WIFEXITED(status) && WEXITSTATUS(status)) {
+		warnx("%s exited %d", argv[0], WEXITSTATUS(status));
+	} else if (WIFSIGNALED(status)) {
+		warnx("%s killed %d", argv[0], WTERMSIG(status));
+	}
+
+close:
+	fclose(req);
+	free(buf);
+}
+
+int main(int argc, char *argv[]) {
+	short port = 0;
+	for (int opt; 0 < (opt = getopt(argc, argv, "p:"));) {
+		switch (opt) {
+			break; case 'p': port = atoi(optarg);
+			break; default:  return EX_USAGE;
+		}
+	}
+	if (optind == argc) errx(EX_USAGE, "script required");
+
+	int server = socket(AF_INET, SOCK_STREAM, 0);
+	if (server < 0) err(EX_OSERR, "socket");
+	fcntl(server, F_SETFD, FD_CLOEXEC);
+
+	struct sockaddr_in addr = {
+		.sin_family = AF_INET,
+		.sin_port = htons(port),
+		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
+	};
+	socklen_t addrlen = sizeof(addr);
+	int error = 0
+		|| bind(server, (struct sockaddr *)&addr, addrlen)
+		|| getsockname(server, (struct sockaddr *)&addr, &addrlen)
+		|| listen(server, -1);
+	if (error) err(EX_UNAVAILABLE, "%hd", port);
+
+	char host[NI_MAXHOST], serv[NI_MAXSERV];
+	error = getnameinfo(
+		(struct sockaddr *)&addr, addrlen,
+		host, sizeof(host), serv, sizeof(serv),
+		NI_NOFQDN
+	);
+	if (error) errx(EX_UNAVAILABLE, "getnameinfo: %s", gai_strerror(error));
+	printf("http://%s:%s/\n", host, serv);
+	fflush(stdout);
+
+	setenv("SERVER_SOFTWARE", "quick (and dirty)", 1);
+	setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
+	setenv("SERVER_NAME", host, 1);
+	setenv("SERVER_PORT", serv, 1);
+	setenv("REMOTE_ADDR", "127.0.0.1", 1);
+	setenv("REMOTE_HOST", host, 1);
+	setenv("SCRIPT_NAME", "/", 1);
+
+	signal(SIGPIPE, SIG_IGN);
+	for (int sock; 0 <= (sock = accept(server, NULL, NULL)); close(sock)) {
+		request(sock, &argv[optind]);
+	}
+	err(EX_IOERR, "accept");
+}