/*
Copyright (c) 2013, Kenneth MacKay
Copyright (c) 2014, Emergya (Cloud4all, FP7/2007-2013 grant agreement n° 289016)
All rights reserved.
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "ifaddrs.h"
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/socket.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
typedef struct NetlinkList
{
struct NetlinkList *m_next;
struct nlmsghdr *m_data;
unsigned int m_size;
} NetlinkList;
static int netlink_socket(void)
{
struct sockaddr_nl l_addr;
int l_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if(l_socket < 0)
{
return -1;
}
memset(&l_addr, 0, sizeof(l_addr));
l_addr.nl_family = AF_NETLINK;
if(bind(l_socket, (struct sockaddr *)&l_addr, sizeof(l_addr)) < 0)
{
close(l_socket);
return -1;
}
return l_socket;
}
static int netlink_send(int p_socket, int p_request)
{
char l_buffer[NLMSG_ALIGN(sizeof(struct nlmsghdr)) + NLMSG_ALIGN(sizeof(struct rtgenmsg))];
struct nlmsghdr *l_hdr;
struct rtgenmsg *l_msg;
struct sockaddr_nl l_addr;
memset(l_buffer, 0, sizeof(l_buffer));
l_hdr = (struct nlmsghdr *)l_buffer;
l_msg = (struct rtgenmsg *)NLMSG_DATA(l_hdr);
l_hdr->nlmsg_len = NLMSG_LENGTH(sizeof(*l_msg));
l_hdr->nlmsg_type = p_request;
l_hdr->nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
l_hdr->nlmsg_pid = 0;
l_hdr->nlmsg_seq = p_socket;
l_msg->rtgen_family = AF_UNSPEC;
memset(&l_addr, 0, sizeof(l_addr));
l_addr.nl_family = AF_NETLINK;
return (sendto(p_socket, l_hdr, l_hdr->nlmsg_len, 0, (struct sockaddr *)&l_addr, sizeof(l_addr)));
}
static int netlink_recv(int p_socket, void *p_buffer, size_t p_len)
{
struct sockaddr_nl l_addr;
struct msghdr l_msg;
struct iovec l_iov;
l_iov.iov_base = p_buffer;
l_iov.iov_len = p_len;
for(;;)
{
int l_result;
l_msg.msg_name = (void *)&l_addr;
l_msg.msg_namelen = sizeof(l_addr);
l_msg.msg_iov = &l_iov;
l_msg.msg_iovlen = 1;
l_msg.msg_control = NULL;
l_msg.msg_controllen = 0;
l_msg.msg_flags = 0;
l_result = recvmsg(p_socket, &l_msg, 0);
if(l_result < 0)
{
if(errno == EINTR)
{
continue;
}
return -2;
}
/* Buffer was too small */
if(l_msg.msg_flags & MSG_TRUNC)
{
return -1;
}
return l_result;
}
}
static struct nlmsghdr *getNetlinkResponse(int p_socket, int *p_size, int *p_done)
{
size_t l_size = 4096;
void *l_buffer = NULL;
for(;;)
{
int l_read;
free(l_buffer);
l_buffer = malloc(l_size);
if (l_buffer == NULL)
{
return NULL;
}
l_read = netlink_recv(p_socket, l_buffer, l_size);
*p_size = l_read;
if(l_read == -2)
{
free(l_buffer);
return NULL;
}
if(l_read >= 0)
{
pid_t l_pid = getpid();
struct nlmsghdr *l_hdr;
for(l_hdr = (struct nlmsghdr *)l_buffer; NLMSG_OK(l_hdr, (unsigned int)l_read); l_hdr = (struct nlmsghdr *)NLMSG_NEXT(l_hdr, l_read))
{
if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
{
continue;
}
if(l_hdr->nlmsg_type == NLMSG_DONE)
{
*p_done = 1;
break;
}
if(l_hdr->nlmsg_type == NLMSG_ERROR)
{
free(l_buffer);
return NULL;
}
}
return l_buffer;
}
l_size *= 2;
}
}
static NetlinkList *newListItem(struct nlmsghdr *p_data, unsigned int p_size)
{
NetlinkList *l_item = malloc(sizeof(NetlinkList));
if (l_item == NULL)
{
return NULL;
}
l_item->m_next = NULL;
l_item->m_data = p_data;
l_item->m_size = p_size;
return l_item;
}
static void freeResultList(NetlinkList *p_list)
{
NetlinkList *l_cur;
while(p_list)
{
l_cur = p_list;
p_list = p_list->m_next;
free(l_cur->m_data);
free(l_cur);
}
}
static NetlinkList *getResultList(int p_socket, int p_request)
{
int l_size;
int l_done;
NetlinkList *l_list;
NetlinkList *l_end;
if(netlink_send(p_socket, p_request) < 0)
{
return NULL;
}
l_list = NULL;
l_end = NULL;
l_done = 0;
while(!l_done)
{
NetlinkList *l_item;
struct nlmsghdr *l_hdr = getNetlinkResponse(p_socket, &l_size, &l_done);
/* Error */
if(!l_hdr)
{
freeResultList(l_list);
return NULL;
}
l_item = newListItem(l_hdr, l_size);
if (!l_item)
{
freeResultList(l_list);
return NULL;
}
if(!l_list)
{
l_list = l_item;
}
else
{
l_end->m_next = l_item;
}
l_end = l_item;
}
return l_list;
}
static size_t maxSize(size_t a, size_t b)
{
return (a > b ? a : b);
}
static size_t calcAddrLen(sa_family_t p_family, int p_dataSize)
{
switch(p_family)
{
case AF_INET:
return sizeof(struct sockaddr_in);
case AF_INET6:
return sizeof(struct sockaddr_in6);
case AF_PACKET:
return maxSize(sizeof(struct sockaddr_ll), offsetof(struct sockaddr_ll, sll_addr) + p_dataSize);
default:
return maxSize(sizeof(struct sockaddr), offsetof(struct sockaddr, sa_data) + p_dataSize);
}
}
static void makeSockaddr(sa_family_t p_family, struct sockaddr *p_dest, void *p_data, size_t p_size)
{
switch(p_family)
{
case AF_INET:
memcpy(&((struct sockaddr_in*)p_dest)->sin_addr, p_data, p_size);
break;
case AF_INET6:
memcpy(&((struct sockaddr_in6*)p_dest)->sin6_addr, p_data, p_size);
break;
case AF_PACKET:
memcpy(((struct sockaddr_ll*)p_dest)->sll_addr, p_data, p_size);
((struct sockaddr_ll*)p_dest)->sll_halen = p_size;
break;
default:
memcpy(p_dest->sa_data, p_data, p_size);
break;
}
p_dest->sa_family = p_family;
}
static void addToEnd(struct ifaddrs **p_resultList, struct ifaddrs *p_entry)
{
if(!*p_resultList)
{
*p_resultList = p_entry;
}
else
{
struct ifaddrs *l_cur = *p_resultList;
while(l_cu
