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import of dnsmasq-2.48.tar.gz

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This commit is contained in:
Simon Kelley
2009-06-04 20:32:05 +01:00
parent 73a08a248d
commit 7622fc06ab
37 changed files with 7873 additions and 6709 deletions
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99
src/netlink.c
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@@ -31,6 +31,7 @@
#endif
static struct iovec iov;
static u32 netlink_pid;
static void nl_err(struct nlmsghdr *h);
static void nl_routechange(struct nlmsghdr *h);
@@ -38,6 +39,7 @@ static void nl_routechange(struct nlmsghdr *h);
void netlink_init(void)
{
struct sockaddr_nl addr;
socklen_t slen = sizeof(addr);
addr.nl_family = AF_NETLINK;
addr.nl_pad = 0;
@@ -59,48 +61,63 @@ void netlink_init(void)
}
}
if (daemon->netlinkfd == -1)
if (daemon->netlinkfd == -1 ||
getsockname(daemon->netlinkfd, (struct sockaddr *)&addr, &slen) == 1)
die(_("cannot create netlink socket: %s"), NULL, EC_MISC);
/* save pid assigned by bind() and retrieved by getsockname() */
netlink_pid = addr.nl_pid;
iov.iov_len = 200;
iov.iov_len = 100;
iov.iov_base = safe_malloc(iov.iov_len);
}
static ssize_t netlink_recv(void)
{
struct msghdr msg;
struct sockaddr_nl nladdr;
ssize_t rc;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
while (1)
{
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_name = &nladdr;
msg.msg_namelen = sizeof(nladdr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK)) == -1 && errno == EINTR);
/* 2.2.x doesn't suport MSG_PEEK at all, returning EOPNOTSUPP, so we just grab a
big buffer and pray in that case. */
if (rc == -1 && errno == EOPNOTSUPP)
while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK | MSG_TRUNC)) == -1 && errno == EINTR);
/* make buffer big enough */
if (rc != -1 && (msg.msg_flags & MSG_TRUNC))
{
if (!expand_buf(&iov, 2000))
return -1;
break;
/* Very new Linux kernels return the actual size needed, older ones always return truncated size */
if ((size_t)rc == iov.iov_len)
{
if (expand_buf(&iov, rc + 100))
continue;
}
else
expand_buf(&iov, rc);
}
if (rc == -1 || !(msg.msg_flags & MSG_TRUNC))
break;
if (!expand_buf(&iov, iov.iov_len + 100))
return -1;
}
/* finally, read it for real */
while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && errno == EINTR);
/* read it for real */
msg.msg_flags = 0;
while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && errno == EINTR);
/* Make sure this is from the kernel */
if (rc == -1 || nladdr.nl_pid == 0)
break;
}
/* discard stuff which is truncated at this point (expand_buf() may fail) */
if (msg.msg_flags & MSG_TRUNC)
{
rc = -1;
errno = ENOMEM;
}
return rc;
}
@@ -141,13 +158,20 @@ int iface_enumerate(void *parm, int (*ipv4_callback)(), int (*ipv6_callback)())
while (1)
{
if ((len = netlink_recv()) == -1)
return 0;
{
if (errno == ENOBUFS)
{
sleep(1);
goto again;
}
return 0;
}
for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
if (h->nlmsg_type == NLMSG_ERROR)
nl_err(h);
else if (h->nlmsg_seq != seq)
if (h->nlmsg_seq != seq || h->nlmsg_pid != netlink_pid)
nl_routechange(h); /* May be multicast arriving async */
else if (h->nlmsg_type == NLMSG_ERROR)
nl_err(h);
else if (h->nlmsg_type == NLMSG_DONE)
{
#ifdef HAVE_IPV6
@@ -208,10 +232,17 @@ int iface_enumerate(void *parm, int (*ipv4_callback)(), int (*ipv6_callback)())
}
}
void netlink_multicast(void)
{
ssize_t len;
struct nlmsghdr *h;
int flags;
/* don't risk blocking reading netlink messages here. */
if ((flags = fcntl(daemon->netlinkfd, F_GETFL)) == -1 ||
fcntl(daemon->netlinkfd, F_SETFL, flags | O_NONBLOCK) == -1)
return;
if ((len = netlink_recv()) != -1)
{
@@ -221,11 +252,15 @@ void netlink_multicast(void)
else
nl_routechange(h);
}
/* restore non-blocking status */
fcntl(daemon->netlinkfd, F_SETFL, flags);
}
static void nl_err(struct nlmsghdr *h)
{
struct nlmsgerr *err = NLMSG_DATA(h);
if (err->error != 0)
my_syslog(LOG_ERR, _("netlink returns error: %s"), strerror(-(err->error)));
}
@@ -234,10 +269,10 @@ static void nl_err(struct nlmsghdr *h)
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. */
failing. Note that we only accept these messages from the kernel (pid == 0) */
static void nl_routechange(struct nlmsghdr *h)
{
if (h->nlmsg_type == RTM_NEWROUTE)
if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE)
{
struct rtmsg *rtm = NLMSG_DATA(h);
int fd;