You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

120 lines
3.2 KiB

From 2675f2061525bc954be14988d64384b74aa7bf8b Mon Sep 17 00:00:00 2001
From: Beniamino Galvani <bgalvani@redhat.com>
Date: Sun, 28 Aug 2016 20:44:05 +0100
Subject: [PATCH] Handle binding upstream servers to an interface
(--server=1.2.3.4@eth0) when the named interface is destroyed and recreated
in the kernel.
---
CHANGELOG | 5 +++++
src/dnsmasq.h | 1 +
src/network.c | 31 +++++++++++++++++++++++++++++--
3 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index 27385a9..f239ce5 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -488,6 +488,7 @@ struct serverfd {
int fd;
union mysockaddr source_addr;
char interface[IF_NAMESIZE+1];
+ unsigned int ifindex, used;
struct serverfd *next;
};
diff --git a/src/network.c b/src/network.c
index e7722fd..ddf8d31 100644
--- a/src/network.c
+++ b/src/network.c
@@ -1204,6 +1204,7 @@ int local_bind(int fd, union mysockaddr *addr, char *intname, int is_tcp)
static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname)
{
struct serverfd *sfd;
+ unsigned int ifindex = 0;
int errsave;
/* when using random ports, servers which would otherwise use
@@ -1224,11 +1225,15 @@ static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname)
return NULL;
#endif
}
+
+ if (intname && strlen(intname) != 0)
+ ifindex = if_nametoindex(intname); /* index == 0 when not binding to an interface */
/* may have a suitable one already */
for (sfd = daemon->sfds; sfd; sfd = sfd->next )
if (sockaddr_isequal(&sfd->source_addr, addr) &&
- strcmp(intname, sfd->interface) == 0)
+ strcmp(intname, sfd->interface) == 0 &&
+ ifindex == sfd->ifindex)
return sfd;
/* need to make a new one. */
@@ -1250,11 +1255,13 @@ static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname)
errno = errsave;
return NULL;
}
-
+
strcpy(sfd->interface, intname);
sfd->source_addr = *addr;
sfd->next = daemon->sfds;
+ sfd->ifindex = ifindex;
daemon->sfds = sfd;
+
return sfd;
}
@@ -1429,12 +1436,16 @@ void check_servers(void)
{
struct irec *iface;
struct server *serv;
+ struct serverfd *sfd, *tmp, **up;
int port = 0, count;
/* interface may be new since startup */
if (!option_bool(OPT_NOWILD))
enumerate_interfaces(0);
+ for (sfd = daemon->sfds; sfd; sfd = sfd->next)
+ sfd->used = 0;
+
#ifdef HAVE_DNSSEC
/* Disable DNSSEC validation when using server=/domain/.... servers
unless there's a configured trust anchor. */
@@ -1505,6 +1516,8 @@ void check_servers(void)
serv->flags |= SERV_MARK;
continue;
}
+
+ serv->sfd->used = 1;
}
if (!(serv->flags & SERV_NO_REBIND) && !(serv->flags & SERV_LITERAL_ADDRESS))
@@ -1547,6 +1560,20 @@ void check_servers(void)
if (count - 1 > SERVERS_LOGGED)
my_syslog(LOG_INFO, _("using %d more nameservers"), count - SERVERS_LOGGED - 1);
+ /* Remove unused sfds */
+ for (sfd = daemon->sfds, up = &daemon->sfds; sfd; sfd = tmp)
+ {
+ tmp = sfd->next;
+ if (!sfd->used)
+ {
+ *up = sfd->next;
+ close(sfd->fd);
+ free(sfd);
+ }
+ else
+ up = &sfd->next;
+ }
+
cleanup_servers();
}
--
2.7.4