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// SPDX-License-Identifier: GPL-2.0-or-later
/* NHRP daemon Linux specific glue
* Copyright (c) 2014-2015 Timo Teräs
*/
#include "zebra.h"
#include <fcntl.h>
#include <errno.h>
#include <linux/if_packet.h>
#include "nhrp_protocol.h"
#include "os.h"
#ifndef HAVE_STRLCPY
size_t strlcpy(char *__restrict dest,
const char *__restrict src, size_t destsize);
#endif
static int nhrp_socket_fd = -1;
int os_socket(void)
{
if (nhrp_socket_fd < 0)
nhrp_socket_fd =
socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_NHRP));
return nhrp_socket_fd;
}
int os_sendmsg(const uint8_t *buf, size_t len, int ifindex, const uint8_t *addr,
size_t addrlen, uint16_t protocol)
{
struct sockaddr_ll lladdr;
struct iovec iov = {
.iov_base = (void *)buf, .iov_len = len,
};
struct msghdr msg = {
.msg_name = &lladdr,
.msg_namelen = sizeof(lladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
int status, fd;
if (addrlen > sizeof(lladdr.sll_addr))
return -1;
memset(&lladdr, 0, sizeof(lladdr));
lladdr.sll_family = AF_PACKET;
lladdr.sll_protocol = htons(protocol);
lladdr.sll_ifindex = ifindex;
lladdr.sll_halen = addrlen;
memcpy(lladdr.sll_addr, addr, addrlen);
fd = os_socket();
if (fd < 0)
return -1;
status = sendmsg(fd, &msg, 0);
if (status < 0)
return -errno;
return status;
}
int os_recvmsg(uint8_t *buf, size_t *len, int *ifindex, uint8_t *addr,
size_t *addrlen)
{
struct sockaddr_ll lladdr;
struct iovec iov = {
.iov_base = buf, .iov_len = *len,
};
struct msghdr msg = {
.msg_name = &lladdr,
.msg_namelen = sizeof(lladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
int r;
r = recvmsg(nhrp_socket_fd, &msg, MSG_DONTWAIT);
if (r < 0)
return r;
*len = r;
*ifindex = lladdr.sll_ifindex;
if (*addrlen <= (size_t)lladdr.sll_addr) {
if (memcmp(lladdr.sll_addr, "\x00\x00\x00\x00", 4) != 0) {
memcpy(addr, lladdr.sll_addr, lladdr.sll_halen);
*addrlen = lladdr.sll_halen;
} else {
*addrlen = 0;
}
}
return 0;
}
static int linux_icmp_redirect_off(const char *iface)
{
char fname[PATH_MAX];
int fd, ret = -1;
snprintf(fname, sizeof(fname),
"/proc/sys/net/ipv4/conf/%s/send_redirects", iface);
fd = open(fname, O_WRONLY);
if (fd < 0)
return -1;
if (write(fd, "0\n", 2) == 2)
ret = 0;
close(fd);
return ret;
}
int os_configure_dmvpn(unsigned int ifindex, const char *ifname, int af)
{
int ret = 0;
switch (af) {
case AF_INET:
ret |= linux_icmp_redirect_off("all");
ret |= linux_icmp_redirect_off(ifname);
break;
}
return ret;
}
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