2020-05-08 17:46:08 +00:00
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// SPDX-License-Identifier: GPL-2.0-only
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#include <errno.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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2020-05-14 20:03:48 +00:00
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#include <sys/epoll.h>
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2020-05-08 17:46:08 +00:00
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#include <linux/err.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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2020-05-14 20:03:48 +00:00
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#include "bpf_util.h"
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2020-05-08 17:46:08 +00:00
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#include "network_helpers.h"
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#define clean_errno() (errno == 0 ? "None" : strerror(errno))
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#define log_err(MSG, ...) fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
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__FILE__, __LINE__, clean_errno(), ##__VA_ARGS__)
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2020-05-08 17:46:09 +00:00
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struct ipv4_packet pkt_v4 = {
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.eth.h_proto = __bpf_constant_htons(ETH_P_IP),
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.iph.ihl = 5,
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.iph.protocol = IPPROTO_TCP,
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.iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),
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.tcp.urg_ptr = 123,
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.tcp.doff = 5,
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};
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struct ipv6_packet pkt_v6 = {
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.eth.h_proto = __bpf_constant_htons(ETH_P_IPV6),
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.iph.nexthdr = IPPROTO_TCP,
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.iph.payload_len = __bpf_constant_htons(MAGIC_BYTES),
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.tcp.urg_ptr = 123,
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.tcp.doff = 5,
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};
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2020-05-08 17:46:08 +00:00
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int start_server(int family, int type)
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{
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struct sockaddr_storage addr = {};
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socklen_t len;
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int fd;
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if (family == AF_INET) {
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struct sockaddr_in *sin = (void *)&addr;
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sin->sin_family = AF_INET;
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len = sizeof(*sin);
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} else {
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struct sockaddr_in6 *sin6 = (void *)&addr;
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sin6->sin6_family = AF_INET6;
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len = sizeof(*sin6);
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}
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fd = socket(family, type | SOCK_NONBLOCK, 0);
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if (fd < 0) {
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log_err("Failed to create server socket");
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return -1;
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}
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if (bind(fd, (const struct sockaddr *)&addr, len) < 0) {
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log_err("Failed to bind socket");
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close(fd);
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return -1;
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}
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if (type == SOCK_STREAM) {
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if (listen(fd, 1) < 0) {
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log_err("Failed to listed on socket");
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close(fd);
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return -1;
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}
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}
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return fd;
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}
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static const struct timeval timeo_sec = { .tv_sec = 3 };
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static const size_t timeo_optlen = sizeof(timeo_sec);
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int connect_to_fd(int family, int type, int server_fd)
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{
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2020-05-14 20:03:48 +00:00
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int fd, save_errno;
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2020-05-08 17:46:08 +00:00
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fd = socket(family, type, 0);
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if (fd < 0) {
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log_err("Failed to create client socket");
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return -1;
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}
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2020-05-14 20:03:48 +00:00
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if (connect_fd_to_fd(fd, server_fd) < 0 && errno != EINPROGRESS) {
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save_errno = errno;
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close(fd);
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errno = save_errno;
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return -1;
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}
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return fd;
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}
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int connect_fd_to_fd(int client_fd, int server_fd)
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{
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struct sockaddr_storage addr;
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socklen_t len = sizeof(addr);
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int save_errno;
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if (setsockopt(client_fd, SOL_SOCKET, SO_RCVTIMEO, &timeo_sec,
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timeo_optlen)) {
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2020-05-08 17:46:08 +00:00
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log_err("Failed to set SO_RCVTIMEO");
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2020-05-14 20:03:48 +00:00
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return -1;
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2020-05-08 17:46:08 +00:00
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}
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if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) {
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log_err("Failed to get server addr");
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2020-05-14 20:03:48 +00:00
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return -1;
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2020-05-08 17:46:08 +00:00
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}
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2020-05-14 20:03:48 +00:00
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if (connect(client_fd, (const struct sockaddr *)&addr, len) < 0) {
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if (errno != EINPROGRESS) {
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save_errno = errno;
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log_err("Failed to connect to server");
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errno = save_errno;
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}
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return -1;
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2020-05-08 17:46:08 +00:00
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}
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2020-05-14 20:03:48 +00:00
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return 0;
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}
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int connect_wait(int fd)
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{
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struct epoll_event ev = {}, events[2];
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int timeout_ms = 1000;
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int efd, nfd;
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efd = epoll_create1(EPOLL_CLOEXEC);
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if (efd < 0) {
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log_err("Failed to open epoll fd");
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return -1;
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}
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ev.events = EPOLLRDHUP | EPOLLOUT;
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ev.data.fd = fd;
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if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ev) < 0) {
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log_err("Failed to register fd=%d on epoll fd=%d", fd, efd);
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close(efd);
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return -1;
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}
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nfd = epoll_wait(efd, events, ARRAY_SIZE(events), timeout_ms);
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if (nfd < 0)
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log_err("Failed to wait for I/O event on epoll fd=%d", efd);
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2020-05-08 17:46:08 +00:00
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2020-05-14 20:03:48 +00:00
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close(efd);
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return nfd;
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2020-05-08 17:46:08 +00:00
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}
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