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/*
* fwd - OpenWrt firewall daemon - rtnetlink communication
*
* Copyright (C) 2009 Jo-Philipp Wich <xm@subsignal.org>
*
* The fwd program is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* The fwd program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with the fwd program. If not, see http://www.gnu.org/licenses/.
*/
#include "fwd.h"
#include "fwd_addr.h"
#include "fwd_utils.h"
struct fwd_addr * fwd_get_addrs(int fd, int family)
{
struct {
struct nlmsghdr n;
struct ifaddrmsg r;
} req;
int offlen;
int rtattrlen;
int dump_done;
char buf[16384];
struct rtattr *rta;
struct rtattr *rtatp;
struct nlmsghdr *nlmp;
struct ifaddrmsg *rtmp;
struct fwd_addr *head, *entry;
/* Build request */
memset(&req, 0, sizeof(req));
req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
req.n.nlmsg_type = RTM_GETADDR;
req.r.ifa_family = family;
rta = (struct rtattr *)(((char *)&req) + NLMSG_ALIGN(req.n.nlmsg_len));
rta->rta_len = RTA_LENGTH(family == AF_INET ? 4 : 16);
head = entry = NULL;
/* Send request */
if( send(fd, &req, sizeof(req), 0) <= 0 )
goto error;
/* Receive responses */
for( dump_done = 0; !dump_done; )
{
if( (offlen = recv(fd, buf, sizeof(buf), 0)) <= 0 )
goto error;
/* Parse message */
for(nlmp = (struct nlmsghdr *)buf; offlen > sizeof(*nlmp);)
{
/* Dump finished? */
if( nlmp->nlmsg_type == NLMSG_DONE )
{
dump_done = 1;
break;
}
int len = nlmp->nlmsg_len;
int req_len = len - sizeof(*nlmp);
if( req_len<0 || len>offlen )
goto error;
if( !NLMSG_OK(nlmp, offlen) )
goto error;
rtmp = (struct ifaddrmsg *) NLMSG_DATA(nlmp);
rtatp = (struct rtattr *) IFA_RTA(rtmp);
if( !(entry = fwd_alloc_ptr(struct fwd_addr)) )
goto error;
entry->index = rtmp->ifa_index;
if_indextoname(rtmp->ifa_index, (char *)&entry->ifname);
rtattrlen = IFA_PAYLOAD(nlmp);
for( ; RTA_OK(rtatp, rtattrlen); rtatp = RTA_NEXT(rtatp, rtattrlen) )
{
if( rtatp->rta_type == IFA_ADDRESS )
{
memcpy(&entry->ipaddr.addr, (char *) RTA_DATA(rtatp), rtatp->rta_len);
entry->ipaddr.prefix = rtmp->ifa_prefixlen;
entry->family = family;
}
else if( rtatp->rta_type == IFA_LABEL)
{
memcpy(&entry->label, (char *) RTA_DATA(rtatp), rtatp->rta_len);
}
}
entry->next = head;
head = entry;
offlen -= NLMSG_ALIGN(len);
nlmp = (struct nlmsghdr*)((char*)nlmp + NLMSG_ALIGN(len));
}
}
return head;
error:
fwd_free_addrs(head);
head = entry = NULL;
return NULL;
}
struct fwd_cidr * fwd_lookup_addr(struct fwd_addr *head, const char *ifname)
{
struct fwd_addr *entry;
for( entry = head; entry; entry = entry->next )
if( !strncmp(entry->ifname, ifname, IFNAMSIZ) )
return &entry->ipaddr;
return NULL;
}
void fwd_free_addrs(struct fwd_addr *head)
{
struct fwd_addr *entry = head;
while( entry != NULL )
{
head = entry->next;
free(entry);
entry = head;
}
head = entry = NULL;
}
struct fwd_addr * fwd_append_addrs(struct fwd_addr *head, struct fwd_addr *add)
{
struct fwd_addr *entry = head;
while( entry->next != NULL )
entry = entry->next;
return (entry->next = add);
}
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