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/* 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 <err.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <poll.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[]) {
struct pollfd pfd = { .fd = sock, .events = POLLIN };
int nfds = poll(&pfd, 1, -1);
if (nfds < 0) err(EX_OSERR, "poll");
char buf[4096];
ssize_t len = recv(sock, buf, sizeof(buf)-1, MSG_PEEK);
if (len < 0) {
warn("recv");
return;
}
char *blank = memmem(buf, len, "\r\n\r\n", 4);
if (!blank) {
warnx("can't find end of request headers in peek");
return;
}
len = recv(sock, buf, &blank[4] - buf, 0);
if (len < 0) {
warn("recv");
return;
}
buf[len] = '\0';
char *ptr = buf;
char *req = strsep(&ptr, "\r\n");
char *method = strsep(&req, " ");
char *query = strsep(&req, " ");
char *path = strsep(&query, "?");
char *proto = strsep(&req, " ");
if (!method || !path || !proto) {
warnx("invalid request line");
return;
}
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");
while (ptr) {
char *value = strsep(&ptr, "\r\n");
if (!value[0]) continue;
char *header = strsep(&value, ":");
if (!header || !value++) {
warnx("invalid header");
return;
}
if (!strcasecmp(header, "Content-Type")) {
setenv("CONTENT_TYPE", value, 1);
} else if (!strcasecmp(header, "Content-Length")) {
setenv("CONTENT_LENGTH", value, 1);
} else if (!strcasecmp(header, "Host")) {
setenv("HTTP_HOST", value, 1);
}
}
dprintf(sock, "HTTP/1.1 200 OK\nConnection: close\n");
pid_t pid = fork();
if (pid < 0) err(EX_OSERR, "fork");
if (!pid) {
dup2(sock, STDIN_FILENO);
dup2(sock, STDOUT_FILENO);
execv(argv[0], argv);
warn("%s", argv[0]);
_exit(127);
}
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));
}
}
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);
int on = 1;
setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
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 | NI_NUMERICSERV
);
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);
for (int sock; 0 <= (sock = accept(server, NULL, NULL)); close(sock)) {
fcntl(sock, F_SETFD, FD_CLOEXEC);
request(sock, &argv[optind]);
}
err(EX_IOERR, "accept");
}
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