commit 460d9f75e27caaaf8b06a85dcda5833c022913c6
Author: hhvn <dev@hhvn.uk>
Date: Wed, 16 Jun 2021 20:48:29 +0100
makefile mitmd.c arg.h: init
Diffstat:
| A | arg.h | | | 70 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | makefile | | | 6 | ++++++ |
| A | mitmd.c | | | 197 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
3 files changed, 273 insertions(+), 0 deletions(-)
diff --git a/arg.h b/arg.h
@@ -0,0 +1,70 @@
+/*
+ * Copy me if you can.
+ * by 20h
+ *
+ * 2012-2016 Christoph Lohmann <20h at r-36 dot net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef ARG_H__
+#define ARG_H__
+
+extern char *argv0;
+
+/* use main(int argc, char *argv[]) */
+#define ARGBEGIN for (argv0 = *argv, argv++, argc--;\
+ argv[0] && argv[0][0] == '-'\
+ && argv[0][1];\
+ argc--, argv++) {\
+ char argc_;\
+ char **argv_;\
+ int brk_;\
+ if (argv[0][1] == '-' && argv[0][2] == '\0') {\
+ argv++;\
+ argc--;\
+ break;\
+ }\
+ int i_;\
+ for (i_ = 1, brk_ = 0, argv_ = argv;\
+ argv[0][i_] && !brk_;\
+ i_++) {\
+ if (argv_ != argv)\
+ break;\
+ argc_ = argv[0][i_];\
+ switch (argc_)
+
+#define ARGEND }\
+ }
+
+#define ARGC() argc_
+
+#define EARGF(x) ((argv[0][i_+1] == '\0' && argv[1] == NULL)?\
+ ((x), abort(), (char *)0) :\
+ (brk_ = 1, (argv[0][i_+1] != '\0')?\
+ (&argv[0][i_+1]) :\
+ (argc--, argv++, argv[0])))
+
+#define ARGF() ((argv[0][i_+1] == '\0' && argv[1] == NULL)?\
+ (char *)0 :\
+ (brk_ = 1, (argv[0][i_+1] != '\0')?\
+ (&argv[0][i_+1]) :\
+ (argc--, argv++, argv[0])))
+
+#endif
diff --git a/makefile b/makefile
@@ -0,0 +1,6 @@
+BIN = mitmd
+
+build: $(BIN)
+
+.c:
+ $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $<
diff --git a/mitmd.c b/mitmd.c
@@ -0,0 +1,197 @@
+/* Copyright (c) 2021 hhvn <dev@hhvn.uk> */
+
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <libgen.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "arg.h"
+
+#define CQUEUE 255
+#define CLIENT_STYLE "\033[96m>\033[0m"
+#define REMOTE_STYLE "\033[90m<\033[0m"
+
+char *argv0;
+char *myhost = "localhost",
+ *myport = "9999",
+ *host,
+ *port;
+
+void
+die(const int exitc, const char *format, ...) {
+ va_list ap;
+
+ va_start(ap, format);
+ fprintf(stderr, "Fatal: ");
+ vfprintf(stderr, format, ap);
+ va_end(ap);
+
+ exit(exitc);
+}
+
+void
+sighandler(int signal) {
+ switch (signal) {
+ case SIGCHLD:
+ while (waitpid(-1, NULL, WNOHANG) == 0);
+ break;
+ default:
+ exit(EXIT_SUCCESS);
+ }
+}
+
+int
+read_line(int fd, char *dest, size_t len) {
+ size_t i = 0;
+ char c = 0;
+
+ do {
+ if (read(fd, &c, sizeof(char)) != sizeof(char))
+ return 0;
+ dest[i++] = c;
+ } while (c != '\n' && i < len);
+
+ dest[i] = '\0';
+ return 1;
+}
+
+
+int
+getsock(struct addrinfo *hints, char *host, char *port) {
+ struct addrinfo *ai;
+ int sret, sockopt;
+ int fd;
+
+ if ((sret = getaddrinfo(host, port, hints, &ai)) != 0 || ai == NULL)
+ die(1, "getaddrinfo() for %s:%s, %s\n", host, port, gai_strerror(sret));
+
+ fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+ sockopt = 1;
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (int*)&sockopt, sizeof(int)) == -1)
+ die(1, "setsockopt(): %s\n", strerror(errno));
+ if (bind(fd, ai->ai_addr, ai->ai_addrlen) == -1)
+ die(1, "bind(): %s\n", strerror(errno));
+ if (listen(fd, CQUEUE) == -1)
+ die(1, "listen(): %s\n", strerror(errno));
+
+ freeaddrinfo(ai);
+
+ return fd;
+}
+
+void
+mitm(int client, char *host, char *port) {
+ struct addrinfo hints;
+ struct addrinfo *ai;
+ char bufc[NL_TEXTMAX];
+ char bufr[NL_TEXTMAX];
+ int sret, remote;
+ pid_t pid;
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_socktype = SOCK_STREAM;
+
+ if ((sret = getaddrinfo(host, port, &hints, &ai)) != 0 || ai == NULL) {
+ dprintf(client, "%s%s\n", "getaddrinfo(): ", gai_strerror(sret));
+ goto cleanup;
+ }
+ if ((remote = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol)) == 1) {
+ dprintf(client, "%s%s\n", "socket(): ", strerror(errno));
+ goto cleanup;
+ }
+ if (connect(remote, ai->ai_addr, ai->ai_addrlen) == -1) {
+ dprintf(client, "%s%s\n", "connect(): ", strerror(errno));
+ goto cleanup;
+ }
+
+ switch (pid = fork()) {
+ case -1:
+ goto cleanup;
+ case 0:
+ while (read_line(client, bufc, sizeof(bufc)) != 0) {
+ printf("%03d%s%03d %s", client, CLIENT_STYLE, remote, bufc);
+ write(remote, bufc, strlen(bufc));
+ }
+ exit(EXIT_SUCCESS);
+ default:
+ while (read_line(remote, bufr, sizeof(bufr)) != 0) {
+ printf("%03d%s%03d %s", client, REMOTE_STYLE, remote, bufr);
+ write(client, bufr, strlen(bufr));
+ }
+ goto cleanup;
+ }
+
+cleanup:
+ freeaddrinfo(&hints);
+ freeaddrinfo(ai);
+}
+
+void
+usage(void) {
+ fprintf(stderr, "usage: %s [-i myinterface] [-p myport] host port\n", basename(argv0));
+ exit(2);
+}
+
+int
+main(int argc, char *argv[]) {
+ struct sockaddr_storage addr;
+ struct addrinfo hints;
+ socklen_t addrlen;
+ int sock, handle;
+ pid_t pid;
+
+ ARGBEGIN {
+ case 'i':
+ myhost = EARGF(usage());
+ break;
+ case 'p':
+ myport = EARGF(usage());
+ break;
+ default:
+ usage();
+ } ARGEND;
+
+ if (argc != 2)
+ usage();
+
+ host = argv[0];
+ port = argv[1];
+
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_flags = AI_PASSIVE;
+ hints.ai_socktype = SOCK_STREAM;
+ sock = getsock(&hints, myhost, myport);
+
+ signal(SIGCHLD, sighandler);
+
+ for (;;) {
+ addrlen = sizeof(addr);
+ if ((handle = accept(sock, (struct sockaddr *)&addr, &addrlen)) == -1)
+ die(1, "accept(): %s\n", strerror(errno));
+
+ switch (pid = fork()) {
+ case -1:
+ fprintf(stderr, "fork(): %s\n", strerror(errno));
+ shutdown(handle, SHUT_RDWR);
+ close(handle);
+ break;
+ case 0:
+ mitm(handle, host, port);
+ shutdown(handle, SHUT_RDWR);
+ close(handle);
+ exit(EXIT_SUCCESS);
+ }
+ }
+
+ return EXIT_SUCCESS;
+}
