initial commit

1 files changed, 440 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..d08336b
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,440 @@
+/*
+ * Copyright (C) 2021 Soleta Networks <info@soleta.eu>
+ *
+ * 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.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <ev.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/fcntl.h>
+#include <unistd.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <syslog.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <sys/time.h>
+#include <limits.h>
+#include <syslog.h>
+
+#define TIP_TORRENT_PORT	9999
+
+/* number of chunks for files. */
+#define MAX_CHUNKS		4
+
+#define container_of(ptr, type, member) ({			\
+	typeof( ((type *)0)->member ) *__mptr = (ptr);		\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+static const char *filename;
+static const char *addr;
+struct ev_loop *tip_main_loop;
+
+enum {
+	TIP_CLIENT_RECEIVING_HEADER,
+	TIP_CLIENT_RECEIVING_PAYLOAD,
+	TIP_CLIENT_NOTIFY_REDIRECT,
+	TIP_CLIENT_DONE,
+};
+
+struct tip_client {
+	ev_io io;
+	struct sockaddr_in addr;
+	char buf[10240000];
+	uint32_t buf_len;
+	uint64_t data_len;
+	uint64_t content_len;
+	int state;
+	int fd;
+	bool error;
+	bool redirected;
+	const char *payload;
+};
+
+static struct tip_client _cli = {
+	.fd = -1,
+};
+
+struct {
+	uint32_t	direct_from_server;
+	uint32_t	redirects;
+} tip_client_stats;
+
+static int tip_client_recv(struct tip_client *cli, int events)
+{
+	struct ev_io *io = &cli->io;
+	int ret;
+
+	ret = recv(io->fd, cli->buf + cli->buf_len,
+		   sizeof(cli->buf) - cli->buf_len, 0);
+	if (ret < 0) {
+		syslog(LOG_ERR, "error reading from server %s:%hu (%s)\n",
+		       inet_ntoa(cli->addr.sin_addr), ntohs(cli->addr.sin_port),
+		       strerror(errno));
+	}
+
+	return ret;
+}
+
+static void tip_client_close(struct tip_client *cli)
+{
+	ev_io_stop(tip_main_loop, &cli->io);
+	shutdown(cli->io.fd, SHUT_RDWR);
+	close(cli->io.fd);
+	cli->buf_len = 0;
+}
+
+static void tip_client_error(struct tip_client *cli)
+{
+	cli->error = true;
+	tip_client_close(cli);
+}
+
+static int tip_client_connect(const char *addr);
+
+static int tip_client_state_recv_hdr(struct tip_client *cli)
+{
+	char *ptr, *trailer, *payload;
+	char redirect_addr[32];
+	uint32_t payload_len;
+	uint32_t header_len;
+	int ret;
+
+	ptr = strstr(cli->buf, "\r\n\r\n");
+	if (!ptr)
+		return 0;
+
+	if (!strncmp(cli->buf, "HTTP/1.1 404 Not Found", strlen("HTTP/1.1 404 Not Found"))) {
+		syslog(LOG_ERR, "server says file `%s' not found\n", filename);
+		return -1;
+	}
+	if (!strncmp(cli->buf, "HTTP/1.1 301 Moves Permanently", strlen("HTTP/1.1 301 Moves Permanently"))) {
+		ptr = strstr(cli->buf, "Location:");
+		if (!ptr)
+			return -1;
+
+		ret = sscanf(ptr, "Location: http://%31s[^\r\n]",
+			     redirect_addr);
+		if (ret != 1)
+			return -1;
+
+		ptr = strchr(redirect_addr, ':');
+		if (!ptr)
+			return -1;
+
+		ptr[0] = '\0';
+
+		syslog(LOG_INFO, "Redirected to %s to fetch file %s\n",
+		       redirect_addr, filename);
+
+		cli->redirected = true;
+		tip_client_close(cli);
+		tip_client_connect(redirect_addr);
+		cli->state = TIP_CLIENT_RECEIVING_HEADER;
+
+		return 0;
+	}
+
+	trailer = ptr + 4;
+
+	ptr = strstr(cli->buf, "Content-Length: ");
+	if (!ptr)
+		return -1;
+
+	if (sscanf(ptr, "Content-Length: %lu[^\r\n]", &cli->content_len) != 1)
+		return -1;
+	if (cli->content_len < 0)
+		return -1;
+
+	if (cli->content_len == 0) {
+		cli->buf_len = 0;
+		return 1;
+	}
+
+	if (cli->redirected)
+		tip_client_stats.redirects++;
+	else
+		tip_client_stats.direct_from_server++;
+
+	cli->fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+	if (cli->fd < 0)
+		return ret;
+
+	header_len = trailer - cli->buf;
+	payload = cli->buf + header_len;
+	payload_len = cli->buf_len - header_len;
+	cli->data_len += cli->buf_len;
+	cli->buf_len = 0;
+
+	if (payload_len > 0) {
+		ret = write(cli->fd, payload, payload_len);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (payload_len >= cli->content_len)
+		return 0;
+
+	return 1;
+}
+
+static int tip_client_state_recv_payload(struct tip_client *cli)
+{
+	int ret;
+
+	cli->data_len += cli->buf_len;
+
+	ret = write(cli->fd, cli->buf, cli->buf_len);
+	if (ret < 0)
+		return ret;
+
+	cli->buf_len = 0;
+
+	if (cli->data_len >= cli->content_len) {
+		if (cli->redirected) {
+			tip_client_close(cli);
+			tip_client_connect(addr);
+			cli->state = TIP_CLIENT_NOTIFY_REDIRECT;
+
+			return 1;
+		}
+		cli->state = TIP_CLIENT_DONE;
+		return 0;
+	}
+
+	return 1;
+}
+
+static int tip_client_state_notify_redirect(struct tip_client *cli)
+{
+	char *ptr;
+
+	ptr = strstr(cli->buf, "\r\n\r\n");
+	if (!ptr)
+		return 0;
+
+	if (strncmp(cli->buf, "HTTP/1.1 200 OK", strlen("HTTP/1.1 200 OK")))
+		return -1;
+
+	ptr = strstr(cli->buf, "Content-Length: ");
+	if (!ptr)
+		return -1;
+
+	if (sscanf(ptr, "Content-Length: %lu[^\r\n]", &cli->content_len) != 1)
+		return -1;
+	if (cli->content_len < 0)
+		return -1;
+
+	if (cli->content_len != 0)
+		return -1;
+
+	cli->state = TIP_CLIENT_DONE;
+
+	return 0;
+}
+
+static void tip_client_read_cb(struct ev_loop *loop, struct ev_io *io, int events)
+{
+	struct tip_client *cli;
+	int ret;
+
+	cli = container_of(io, struct tip_client, io);
+
+	ret = tip_client_recv(cli, events);
+	if (ret < 0)
+		goto error;
+
+	cli->buf_len += ret;
+
+	switch (cli->state) {
+	case TIP_CLIENT_RECEIVING_HEADER:
+		ret = tip_client_state_recv_hdr(cli);
+		if (ret < 0)
+			goto error;
+		if (!ret)
+			return;
+
+		cli->state = TIP_CLIENT_RECEIVING_PAYLOAD;
+		/* Fall through. */
+	case TIP_CLIENT_RECEIVING_PAYLOAD:
+		ret = tip_client_state_recv_payload(cli);
+		if (ret < 0)
+			goto error;
+		if (ret == 0)
+			goto close;
+		break;
+	case TIP_CLIENT_NOTIFY_REDIRECT:
+		ret = tip_client_state_notify_redirect(cli);
+		if (ret < 0)
+			goto error;
+		if (ret == 0)
+			goto close;
+		break;
+	}
+	return;
+error:
+	tip_client_error(cli);
+	return;
+close:
+	tip_client_close(cli);
+	return;
+}
+
+static void tip_client_connect_cb(struct ev_loop *loop, struct ev_io *io, int events)
+{
+	struct tip_client *cli;
+	char buf[PATH_MAX + 1];
+	int ret, len;
+
+	cli = container_of(io, struct tip_client, io);
+
+	if (events & EV_ERROR)
+		return;
+
+	len = sizeof(cli->addr);
+	ret = connect(cli->io.fd, (struct sockaddr *)&cli->addr, len);
+	if (ret < 0) {
+		if (errno != EINPROGRESS) {
+			perror("connect");
+			tip_client_error(cli);
+			return;
+		}
+	}
+
+	if (cli->state == TIP_CLIENT_NOTIFY_REDIRECT)
+		snprintf(buf, sizeof(buf), "POST /%s HTTP/1.1\r\n\r\n", filename);
+	else
+		snprintf(buf, sizeof(buf), "GET /%s HTTP/1.1\r\n\r\n", filename);
+
+	ret = send(cli->io.fd, buf, strlen(buf), 0);
+	if (ret < 0) {
+		tip_client_error(cli);
+		return;
+	}
+
+	ev_io_stop(tip_main_loop, &cli->io);
+	ev_io_init(&cli->io, tip_client_read_cb, cli->io.fd, EV_READ);
+	ev_io_start(tip_main_loop, &cli->io);
+}
+
+static int tip_client_connect(const char *addr)
+{
+	struct tip_client *cli = &_cli;
+	int remote_fd;
+	int flags;
+	int len;
+	int ret;
+
+	remote_fd = socket(AF_INET, SOCK_STREAM, 0);
+	if (remote_fd < 0)
+		return -1;
+
+	flags = fcntl(remote_fd, F_GETFL);
+	flags |= O_NONBLOCK;
+	ret = fcntl(remote_fd, F_SETFL, flags);
+	if (ret < 0)
+		return ret;
+
+	cli->addr.sin_family = AF_INET;
+	cli->addr.sin_addr.s_addr = inet_addr(addr);
+	cli->addr.sin_port = htons(TIP_TORRENT_PORT);
+
+	len = sizeof(cli->addr);
+	ret = connect(remote_fd, (struct sockaddr *)&cli->addr, len);
+	if (ret < 0 && errno != EINPROGRESS) {
+		perror("connect");
+		return ret;
+	}
+
+	ev_io_init(&cli->io, tip_client_connect_cb, remote_fd, EV_WRITE);
+	ev_io_start(tip_main_loop, &cli->io);
+
+	syslog(LOG_INFO, "connecting to %s to fetch file %s\n", addr, filename);
+
+	return 0;
+}
+
+static uint32_t select_file_chunk(bool *file_chunk)
+{
+	struct timeval tv;
+	uint32_t k;
+	int i;
+
+	gettimeofday(&tv, NULL);
+	srand(tv.tv_usec);
+
+	k = rand() % MAX_CHUNKS;
+	for (i = 0; i < MAX_CHUNKS; i++) {
+		if (!file_chunk[k])
+			break;
+
+		k++;
+		if (k == MAX_CHUNKS)
+			k = 0;
+	}
+
+	return k;
+}
+
+static char _filename[PATH_MAX + 1];
+
+int main(int argc, char *argv[])
+{
+	struct timeval tv_start, tv_stop, tv;
+	bool file_chunk[MAX_CHUNKS] = {};
+	int i, k;
+
+	if (argc != 3) {
+		printf("%s [ip] [file]\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+	addr = argv[1];
+
+	openlog("tiptorrent-client", LOG_PID, LOG_DAEMON);
+
+	signal(SIGPIPE, SIG_IGN);
+
+	tip_main_loop = ev_default_loop(0);
+
+	gettimeofday(&tv_start, NULL);
+
+	for (i = 0; i < MAX_CHUNKS; i++) {
+		memset(&_cli, 0, sizeof(_cli));
+
+		k = select_file_chunk(file_chunk);
+		snprintf(_filename, sizeof(_filename), "%s.%u", argv[2], k);
+		filename = _filename;
+
+		syslog(LOG_INFO, "Requesting file %s to server\n", filename);
+
+		tip_client_connect(argv[1]);
+		_cli.state = TIP_CLIENT_RECEIVING_HEADER;
+
+		while (_cli.state != TIP_CLIENT_DONE || _cli.error)
+			ev_loop(tip_main_loop, 0);
+
+		file_chunk[k] = true;
+	}
+
+	if (_cli.state == TIP_CLIENT_DONE) {
+		gettimeofday(&tv_stop, NULL);
+		timersub(&tv_stop, &tv_start, &tv);
+		printf("Done in %lus.%lums. "
+		       "Direct from server: %u Redirected: %u\n",
+		       tv.tv_sec, tv.tv_usec,
+		       tip_client_stats.direct_from_server,
+		       tip_client_stats.redirects);
+		return EXIT_SUCCESS;
+	}
+
+	printf("Failure, see syslog for details.\n");
+	return EXIT_FAILURE;
+}