Pi-Hole/dnsmasq
1
0
Fork 0
mirror of https://github.com/pi-hole/dnsmasq.git synced 2025-12-19 18:28:25 +00:00
Code Issues Packages Projects Releases Wiki Activity

import of dnsmasq-2.27.tar.gz

Browse Source
This commit is contained in:
Simon Kelley
2006-03-16 20:16:06 +00:00
parent aedef83058
commit cdeda28f82
27 changed files with 2427 additions and 1966 deletions
Download Patch File Download Diff File Expand all files Collapse all files

114
src/netlink.c
View File

@@ -1,4 +1,4 @@
/* dnsmasq is Copyright (c) 2000-2005 Simon Kelley
/* dnsmasq is Copyright (c) 2000-2006 Simon Kelley
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -10,8 +10,6 @@
GNU General Public License for more details.
*/
/* Author's email: simon@thekelleys.org.uk */
#include "dnsmasq.h"
#ifdef HAVE_RTNETLINK
@@ -20,35 +18,74 @@
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
int netlink_init(void)
static struct iovec iov[1];
void netlink_init(struct daemon *daemon)
{
struct sockaddr_nl addr;
int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
daemon->netlinkfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (sock < 0)
return -1; /* no kernel support */
if (daemon->netlinkfd < 0)
return; /* no kernel support */
addr.nl_family = AF_NETLINK;
addr.nl_pad = 0;
addr.nl_pid = getpid();
addr.nl_groups = 0;
#ifdef HAVE_IPV6
addr.nl_groups = RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR | RTMGRP_IPV4_ROUTE | RTMGRP_IPV6_ROUTE;
#else
addr.nl_groups = RTMGRP_IPV4_IFADDR | RTMGRP_IPV4_ROUTE;
#endif
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)
if (bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
die(_("cannot bind netlink socket: %s"), NULL);
return sock;
iov[0].iov_len = 200;
iov[0].iov_base = safe_malloc(iov[0].iov_len);
}
static ssize_t netlink_recv(struct daemon *daemon)
{
struct msghdr msg;
ssize_t rc;
/* We borrow the DNS packet buffer here. (The DHCP one already has a packet in it)
Since it's used only within this routine, that's fine, just remember
that calling icmp_echo() will trash it */
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = iov;
msg.msg_iovlen = 1;
retry:
while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK)) == -1 && retry_send());
if (rc == -1)
return -1;
if (msg.msg_flags & MSG_TRUNC)
{
size_t newsz = iov[0].iov_len + 100;
void *new = realloc(iov[0].iov_base, newsz);
if (!new)
return -1;
iov[0].iov_len = newsz;
iov[0].iov_base = new;
goto retry;
}
while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && retry_send());
return rc;
}
int netlink_process(struct daemon *daemon, int index, struct in_addr relay,
struct in_addr primary, struct dhcp_context **retp)
{
struct sockaddr_nl addr;
struct nlmsghdr *h;
int len, found_primary = 0;
int found_primary = 0;
ssize_t len;
struct dhcp_context *ret = NULL;
static unsigned int seq = 0;
@@ -88,17 +125,11 @@ int netlink_process(struct daemon *daemon, int index, struct in_addr relay,
}
get_next:
while((len = recvfrom(daemon->netlinkfd, daemon->packet, daemon->packet_buff_sz,
MSG_WAITALL, NULL, 0)) == -1 && retry_send());
if (len == -1)
if ((len = netlink_recv(daemon)) == -1)
return 0;
h = (struct nlmsghdr *)daemon->packet;
while (NLMSG_OK(h, (unsigned int)len))
for (h = (struct nlmsghdr *)iov[0].iov_base; NLMSG_OK(h, (unsigned int)len); h = NLMSG_NEXT(h, len))
{
if (h->nlmsg_seq != seq)
goto get_next;
@@ -110,8 +141,7 @@ int netlink_process(struct daemon *daemon, int index, struct in_addr relay,
if (h->nlmsg_type == RTM_NEWADDR)
{
struct ifaddrmsg *ifa = NLMSG_DATA(h);
struct ifaddrmsg *ifa = NLMSG_DATA(h);
if (ifa->ifa_index == index && ifa->ifa_family == AF_INET)
{
struct rtattr *rta = IFA_RTA(ifa);
@@ -140,15 +170,43 @@ int netlink_process(struct daemon *daemon, int index, struct in_addr relay,
}
}
}
h = NLMSG_NEXT(h, len);
}
*retp = ret;
return found_primary;
}
/* We arrange to receive netlink multicast messages whenever the network config changes.
If this happens and we still have a DNS packet in the buffer, we re-send it.
This helps on DoD links, where frequently the packet which triggers dialling is
a DNS query, which then gets lost. By re-sending, we can avoid the lookup
failing. */
void netlink_multicast(struct daemon *daemon)
{
ssize_t len;
struct nlmsghdr *h;
if ((len = netlink_recv(daemon)) == -1)
return;
if (!daemon->srv_save)
return;
for (h = (struct nlmsghdr *)iov[0].iov_base; NLMSG_OK(h, (unsigned int)len); h = NLMSG_NEXT(h, len))
{
if (h->nlmsg_type == NLMSG_DONE || h->nlmsg_type == NLMSG_ERROR)
break;
if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_NEWROUTE)
{
while(sendto(daemon->srv_save->sfd->fd, daemon->packet, daemon->packet_len, 0,
&daemon->srv_save->addr.sa, sa_len(&daemon->srv_save->addr)) == -1 && retry_send());
break;
}
}
}
#endif