From c8d6ce89f19aaa459d5a86c7909d3f3b6aac15d4 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Sat, 2 Sep 2023 18:36:29 +0200
Subject: cmd: add socksfs

---
 src/cmd/socksfs/socksfs.c | 165 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 165 insertions(+)
 create mode 100644 src/cmd/socksfs/socksfs.c

(limited to 'src/cmd/socksfs')

diff --git a/src/cmd/socksfs/socksfs.c b/src/cmd/socksfs/socksfs.c
new file mode 100644
index 0000000..4f530f4
--- /dev/null
+++ b/src/cmd/socksfs/socksfs.c
@@ -0,0 +1,165 @@
+#include <camellia/flags.h>
+#include <camellia/syscalls.h>
+#include <camellia/fs/misc.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <camellia.h>
+#include <sys/param.h>
+
+typedef struct {
+	hid_t sock;
+} Handle;
+
+static char *socks_addr;
+
+static void*
+fs_open(char *path, int flags) {
+	char *tokp;
+
+	if (*path++ != '/') {
+		return errno = ENOENT, NULL;
+	}
+	if (!OPEN_WRITEABLE(flags)) {
+		return errno = EACCES, NULL;
+	}
+
+	const char *verb = strtok_r(path, "/", &tokp);
+	if (!verb) {
+		return errno = ENOENT, NULL;
+	}
+	if (strcmp(verb, "connect") != 0) {
+		return errno = ENOSYS, NULL; // unimpl.
+	}
+
+	// TODO ip parsing in stdlib
+	// uint32_t srcip;
+	//if (ip_parse(strtok_r(NULL, "/", &tokp), &srcip) < 0 || srcip != 0) {
+	//	return errno = ENOENT, NULL;
+	//}
+	strtok_r(NULL, "/", &tokp);
+
+	char *dest = strtok_r(NULL, "/", &tokp);
+	if (!dest) return errno = ENOENT, NULL;
+	size_t destlen = strlen(dest);
+	if (destlen >= 256) return errno = ENAMETOOLONG, NULL;
+	// let's assume it's a domain
+
+	char *proto = strtok_r(NULL, "/", &tokp);
+	if (!proto) return errno = ENOENT, NULL;
+	if (strcmp(proto, "tcp") != 0) {
+		return errno = ENOSYS, NULL; // unimpl.
+	}
+	
+	char *port_s = strtok_r(NULL, "/", &tokp);
+	if (!port_s) return errno = ENOENT, NULL;
+	uint16_t port = strtol(port_s, NULL, 0);
+
+	Handle *h;
+	h = calloc(1, sizeof(*h));
+	if (!h) return errno = ENOMEM, NULL;
+
+	h->sock = camellia_open(socks_addr, OPEN_READ | OPEN_WRITE);
+	if (h->sock < 0) {
+		goto err;
+	}
+
+	/* 0x05    version 5
+	 * 0x01    one authentication method:
+	 *   0x00  no auth */
+	char buf[512];
+	sleep(1); // TODO fix the netstack
+	write(h->sock, "\x05\x01\x00", 3);
+
+	errno = EGENERIC;
+	ssize_t ret = read(h->sock, buf, 2);
+	if (ret != 2) goto err; // yeah yeah i know
+	if (memcmp(buf, "\x05\x00", 2) != 0) goto err;
+
+	int p = 0;
+	buf[p++] = 5; /* v5 */
+	buf[p++] = 1; /* tcp connection */
+	buf[p++] = 0; /* reserved */
+	buf[p++] = 3; /* addr type, 3 = domain */
+	buf[p++] = destlen; /* length, max 255 */
+	memcpy(buf + p, dest, destlen);
+	p += destlen;
+	buf[p++] = port >> 8;
+	buf[p++] = port;
+
+	write(h->sock, buf, p);
+
+	ret = read(h->sock, buf, 10);
+	// just comparing to what tor replies, i have bigger issues than making this general
+	if (ret != 10 || memcmp(buf, "\x05\x00\x00\x01\x00\x00\x00\x00\x00\x00", 10) != 0) {
+		goto err;
+	}
+
+	return h;
+
+err:
+	close(h->sock);
+	free(h);
+	return NULL;
+}
+
+int main(int argc, char *argv[]) {
+	const size_t buflen = 4096;
+	char *buf = malloc(buflen);
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: socksfs /net/connect/.../\n");
+		return 1;
+	}
+	socks_addr = argv[1];
+
+	struct ufs_request req;
+	hid_t reqh;
+	// TODO an fs_wait flag to only wait for OPENs, and then to only wait for a given handle
+	// then i can use proper threads
+	while ((reqh = ufs_wait(buf, buflen, &req))) {
+		Handle *h = req.id;
+		switch (req.op) {
+			case VFSOP_OPEN: {
+				void *ret = fs_open(buf, req.flags);
+				if (ret) {
+					_sys_fs_respond(reqh, ret, 0, 0);
+				} else {
+					_sys_fs_respond(reqh, NULL, -errno, 0);
+				}
+				break;
+			}
+			case VFSOP_READ: {
+				if (_sys_fork(FORK_NOREAP, NULL) == 0) {
+					int len = MIN(buflen, req.capacity);
+					len = _sys_read(h->sock, buf, len, -1);
+					_sys_fs_respond(reqh, buf, len, 0);
+					exit(0);
+				} else {
+					close(reqh);
+				}
+				break;
+			}
+			case VFSOP_WRITE: {
+				if (_sys_fork(FORK_NOREAP, NULL) == 0) {
+					int len = _sys_write(h->sock, buf, req.len, -1, 0);
+					_sys_fs_respond(reqh, NULL, len, 0);
+					exit(0);
+				} else {
+					close(reqh);
+				}
+				break;
+			}
+			case VFSOP_CLOSE:
+				close(h->sock);
+				free(h);
+				_sys_fs_respond(reqh, NULL, -1, 0);
+				break;
+			default:
+				_sys_fs_respond(reqh, NULL, -1, 0);
+				break;
+		}
+	}
+}
-- 
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