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// SPDX-License-Identifier: GPL-2.0-only
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/epoll.h>
#include <linux/err.h>
#include <linux/in.h>
#include <linux/in6.h>
#include "bpf_util.h"
#include "network_helpers.h"
#define clean_errno() (errno == 0 ? "None" : strerror(errno))
#define log_err(MSG, ...) fprintf(stderr, "(%s:%d: errno: %s) " MSG "\n", \
__FILE__, __LINE__, clean_errno(), ##__VA_ARGS__)
struct ipv4_packet pkt_v4 = {
.eth.h_proto = __bpf_constant_htons(ETH_P_IP),
.iph.ihl = 5,
.iph.protocol = IPPROTO_TCP,
.iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),
.tcp.urg_ptr = 123,
.tcp.doff = 5,
};
struct ipv6_packet pkt_v6 = {
.eth.h_proto = __bpf_constant_htons(ETH_P_IPV6),
.iph.nexthdr = IPPROTO_TCP,
.iph.payload_len = __bpf_constant_htons(MAGIC_BYTES),
.tcp.urg_ptr = 123,
.tcp.doff = 5,
};
int start_server_with_port(int family, int type, __u16 port)
{
struct sockaddr_storage addr = {};
socklen_t len;
int fd;
if (family == AF_INET) {
struct sockaddr_in *sin = (void *)&addr;
sin->sin_family = AF_INET;
sin->sin_port = htons(port);
len = sizeof(*sin);
} else {
struct sockaddr_in6 *sin6 = (void *)&addr;
sin6->sin6_family = AF_INET6;
sin6->sin6_port = htons(port);
len = sizeof(*sin6);
}
fd = socket(family, type | SOCK_NONBLOCK, 0);
if (fd < 0) {
log_err("Failed to create server socket");
return -1;
}
if (bind(fd, (const struct sockaddr *)&addr, len) < 0) {
log_err("Failed to bind socket");
close(fd);
return -1;
}
if (type == SOCK_STREAM) {
if (listen(fd, 1) < 0) {
log_err("Failed to listed on socket");
close(fd);
return -1;
}
}
return fd;
}
int start_server(int family, int type)
{
return start_server_with_port(family, type, 0);
}
static const struct timeval timeo_sec = { .tv_sec = 3 };
static const size_t timeo_optlen = sizeof(timeo_sec);
int connect_to_fd(int family, int type, int server_fd)
{
int fd, save_errno;
fd = socket(family, type, 0);
if (fd < 0) {
log_err("Failed to create client socket");
return -1;
}
if (connect_fd_to_fd(fd, server_fd) < 0 && errno != EINPROGRESS) {
save_errno = errno;
close(fd);
errno = save_errno;
return -1;
}
return fd;
}
int connect_fd_to_fd(int client_fd, int server_fd)
{
struct sockaddr_storage addr;
socklen_t len = sizeof(addr);
int save_errno;
if (setsockopt(client_fd, SOL_SOCKET, SO_RCVTIMEO, &timeo_sec,
timeo_optlen)) {
log_err("Failed to set SO_RCVTIMEO");
return -1;
}
if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) {
log_err("Failed to get server addr");
return -1;
}
if (connect(client_fd, (const struct sockaddr *)&addr, len) < 0) {
if (errno != EINPROGRESS) {
save_errno = errno;
log_err("Failed to connect to server");
errno = save_errno;
}
return -1;
}
return 0;
}
int connect_wait(int fd)
{
struct epoll_event ev = {}, events[2];
int timeout_ms = 1000;
int efd, nfd;
efd = epoll_create1(EPOLL_CLOEXEC);
if (efd < 0) {
log_err("Failed to open epoll fd");
return -1;
}
ev.events = EPOLLRDHUP | EPOLLOUT;
ev.data.fd = fd;
if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ev) < 0) {
log_err("Failed to register fd=%d on epoll fd=%d", fd, efd);
close(efd);
return -1;
}
nfd = epoll_wait(efd, events, ARRAY_SIZE(events), timeout_ms);
if (nfd < 0)
log_err("Failed to wait for I/O event on epoll fd=%d", efd);
close(efd);
return nfd;
}
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