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Router Advertisement

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This commit is contained in:
Simon Kelley
2012-02-24 16:06:20 +00:00
parent 270dc2e199
commit c5ad4e7998
15 changed files with 758 additions and 121 deletions
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6
Makefile
View File

@@ -47,9 +47,11 @@ VERSION= -DVERSION='\"`../bld/get-version`\"'
OBJS = cache.o rfc1035.o util.o option.o forward.o network.o \
dnsmasq.o dhcp.o lease.o rfc2131.o netlink.o dbus.o bpf.o \
helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o dhcp-common.o
helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o \
dhcp-common.o outpacket.o radv.o
HDRS = dnsmasq.h config.h dhcp_protocol.h dhcp6_protocol.h dns_protocol.h
HDRS = dnsmasq.h config.h dhcp_protocol.h dhcp6_protocol.h \
dns_protocol.h radv_protocol.h
all : $(BUILDDIR)

3
bld/Android.mk
View File

@@ -7,7 +7,8 @@ LOCAL_SRC_FILES := bpf.c cache.c dbus.c dhcp.c dnsmasq.c \
forward.c helper.c lease.c log.c \
netlink.c network.c option.c rfc1035.c \
rfc2131.c tftp.c util.c conntrack.c \
dhcp6.c rfc3315.c dhcp-common.c
dhcp6.c rfc3315.c dhcp-common.c outpacket.c \
radv.c
LOCAL_MODULE := dnsmasq

30
man/dnsmasq.8
View File

@@ -529,14 +529,18 @@ The optional
sets an alphanumeric label which marks this network so that
dhcp options may be specified on a per-network basis.
When it is prefixed with 'tag:' instead, then its meaning changes from setting
a tag to matching it. Only one tag may be set, but more than one tag may be matched.
a tag to matching it. Only one tag may be set, but more than one tag
may be matched.
The end address may be replaced by the keyword
.B static
which tells dnsmasq to enable DHCP for the network specified, but not
to dynamically allocate IP addresses: only hosts which have static
addresses given via
.B dhcp-host
or from /etc/ethers will be served. The end address may be replaced by
or from /etc/ethers will be served.
The end address may be replaced by
the keyword
.B proxy
in which case dnsmasq will provide proxy-DHCP on the specified
@@ -546,6 +550,14 @@ and
.B pxe-service
for details, applies to IPv4 only.)
The end address may be replaced by
the keyword
.B ra-only
which tells dnsmasq to offer Router Advertisement only on this subnet,
and not DHCP. This applies to IPv6 only, see
.B enable-ra
for details.
The interface:<interface name> section is not normally used. See the
NOTES section for details of this.
.TP
@@ -1234,6 +1246,20 @@ added into dnsmasq's DNS view. This flag suppresses that behaviour,
this is useful, for instance, to allow Windows clients to update
Active Directory servers. See RFC 4702 for details.
.TP
.B --enable-ra
Enable dnsmasq's IPv6 Router Advertisement feature. DHCPv6 doesn't
handle complete network configuration in the same way as DHCPv4. Router
discovery and (possibly) prefix discovery for autonomous address
creation are handled by a different protocol. When DHCP is in use,
only a subset of this is needed, and dnsmasq can handle it, using
existing DHCP configuration to provide most data. When RA is enabled,
dnsmasq will advertise a prefix for each dhcp-range, with default
router and recursive DNS server as the relevant link-local address on
the machine running dnsmasq. The "managed address" bits are set,
except for a dhcp-range which is marked as "ra-only". In which case RA
is provided by no DHCPv6 service and the managed address bits are
cleared.
.TP
.B --enable-tftp[=<interface>]
Enable the TFTP server function. This is deliberately limited to that
needed to net-boot a client. Only reading is allowed; the tsize and

3
src/bpf.c
View File

@@ -199,7 +199,8 @@ int iface_enumerate(int family, void *parm, int (*callback)())
{
/* Assume ethernet again here */
struct sockaddr_dl *sdl = (struct sockaddr_dl *)&ifr->ifr_addr;
if (sdl->sdl_alen != 0 && !((*callback)(ARPHRD_ETHER, LLADDR(sdl), sdl->sdl_alen, parm)))
if (sdl->sdl_alen != 0 && !((*callback)((int)if_nametoindex(ifr->ifr_name),
ARPHRD_ETHER, LLADDR(sdl), sdl->sdl_alen, parm)))
goto err;
}
#endif

6
src/dhcp-common.c
View File

@@ -53,14 +53,14 @@ ssize_t recv_dhcp_packet(int fd, struct msghdr *msg)
/* Very new Linux kernels return the actual size needed,
older ones always return truncated size */
if ((size_t)sz == daemon->dhcp_packet.iov_len)
if ((size_t)sz == msg->msg_iov->iov_len)
{
if (!expand_buf(&daemon->dhcp_packet, sz + 100))
if (!expand_buf(msg->msg_iov, sz + 100))
return -1;
}
else
{
expand_buf(&daemon->dhcp_packet, sz);
expand_buf(msg->msg_iov, sz);
break;
}
}

20
src/dhcp6.c
View File

@@ -35,7 +35,7 @@ static int join_multicast(struct in6_addr *local, int prefix,
static int complete_context6(struct in6_addr *local, int prefix,
int scope, int if_index, int dad, void *vparam);
static int make_duid1(unsigned int type, char *mac, size_t maclen, void *parm);
static int make_duid1(int index, unsigned int type, char *mac, size_t maclen, void *parm);
void dhcp6_init(void)
{
@@ -101,6 +101,13 @@ static int join_multicast(struct in6_addr *local, int prefix,
if (if_index == listenp->fd_or_iface)
return 1;
mreq.ipv6mr_interface = if_index;
inet_pton(AF_INET6, ALL_ROUTERS, &mreq.ipv6mr_multiaddr);
if (daemon->icmp6fd != -1 &&
setsockopt(daemon->icmp6fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
return 0;
if (!indextoname(fd, if_index, ifrn_name))
return 0;
@@ -120,7 +127,6 @@ static int join_multicast(struct in6_addr *local, int prefix,
if (!context)
return 1;
mreq.ipv6mr_interface = if_index;
inet_pton(AF_INET6, ALL_RELAY_AGENTS_AND_SERVERS, &mreq.ipv6mr_multiaddr);
if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
@@ -151,7 +157,7 @@ void dhcp6_packet(time_t now)
struct cmsghdr align; /* this ensures alignment */
char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
} control_u;
union mysockaddr from;
struct sockaddr_in6 from;
struct all_addr dest;
ssize_t sz;
struct ifreq ifr;
@@ -215,8 +221,8 @@ void dhcp6_packet(time_t now)
lease_prune(NULL, now); /* lose any expired leases */
msg.msg_iov = &daemon->dhcp_packet;
sz = dhcp6_reply(parm.current, if_index, ifr.ifr_name, &parm.fallback, sz, IN6_IS_ADDR_MULTICAST(&from.in6.sin6_addr), now);
sz = dhcp6_reply(parm.current, if_index, ifr.ifr_name, &parm.fallback,
sz, IN6_IS_ADDR_MULTICAST(&from.sin6_addr), now);
lease_update_file(now);
lease_update_dns();
@@ -455,13 +461,15 @@ void make_duid(time_t now)
die("Cannot create DHCPv6 server DUID: %s", NULL, EC_MISC);
}
static int make_duid1(unsigned int type, char *mac, size_t maclen, void *parm)
static int make_duid1(int index, unsigned int type, char *mac, size_t maclen, void *parm)
{
/* create DUID as specified in RFC3315. We use the MAC of the
first interface we find that isn't loopback or P-to-P */
unsigned char *p;
(void)index;
daemon->duid = p = safe_malloc(maclen + 8);
daemon->duid_len = maclen + 8;

44
src/dnsmasq.c
View File

@@ -157,8 +157,14 @@ int main (int argc, char **argv)
if (daemon->dhcp)
dhcp_init();
#ifdef HAVE_DHCP6
daemon->icmp6fd = -1;
if (daemon->dhcp6)
dhcp6_init();
{
/* ra_init before dhcp6_init, so dhcp6_init can setup multicast listening */
if (option_bool(OPT_RA))
ra_init(now);
dhcp6_init();
}
#endif
}
#endif
@@ -495,6 +501,9 @@ int main (int argc, char **argv)
if (daemon->max_logs != 0)
my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs);
if (option_bool(OPT_RA))
my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled"));
#ifdef HAVE_DHCP
if (daemon->dhcp || daemon->dhcp6)
@@ -525,6 +534,8 @@ int main (int argc, char **argv)
my_syslog(MS_DHCP | LOG_INFO,
(dhcp_tmp->flags & CONTEXT_STATIC) ?
_("DHCP, static leases only on %.0s%s, lease time %s") :
(dhcp_tmp->flags & CONTEXT_RA_ONLY) ?
_("router advertisement only on %.0s%s, lifetime %s") :
(dhcp_tmp->flags & CONTEXT_PROXY) ?
_("DHCP, proxy on subnet %.0s%s%.0s") :
_("DHCP, IP range %s -- %s, lease time %s"),
@@ -535,7 +546,10 @@ int main (int argc, char **argv)
if (family == AF_INET)
{
family = AF_INET6;
dhcp_tmp = daemon->dhcp6;
if (daemon->ra_contexts)
dhcp_tmp = daemon->ra_contexts;
else
dhcp_tmp = daemon->dhcp6;
goto again;
}
#endif
@@ -652,7 +666,13 @@ int main (int argc, char **argv)
if (daemon->dhcp6)
{
FD_SET(daemon->dhcp6fd, &rset);
bump_maxfd(daemon->dhcp6fd, &maxfd);
bump_maxfd(daemon->dhcp6fd, &maxfd);
if (daemon->icmp6fd != -1)
{
FD_SET(daemon->icmp6fd, &rset);
bump_maxfd(daemon->icmp6fd, &maxfd);
}
}
#endif
@@ -756,6 +776,9 @@ int main (int argc, char **argv)
{
if (FD_ISSET(daemon->dhcp6fd, &rset))
dhcp6_packet(now);
if (daemon->icmp6fd != -1 && FD_ISSET(daemon->icmp6fd, &rset))
icmp6_packet();
}
#endif
@@ -1372,7 +1395,15 @@ int icmp_ping(struct in_addr addr)
FD_SET(fd, &rset);
set_dns_listeners(now, &rset, &maxfd);
set_log_writer(&wset, &maxfd);
#ifdef HAVE_DHCP6
if (daemon->icmp6fd != -1)
{
FD_SET(daemon->icmp6fd, &rset);
bump_maxfd(daemon->icmp6fd, &maxfd);
}
#endif
if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0)
{
FD_ZERO(&rset);
@@ -1384,6 +1415,11 @@ int icmp_ping(struct in_addr addr)
check_log_writer(&wset);
check_dns_listeners(&rset, now);
#ifdef HAVE_DHCP6
if (daemon->icmp6fd != -1 && FD_ISSET(daemon->icmp6fd, &rset))
icmp6_packet();
#endif
#ifdef HAVE_TFTP
check_tftp_listeners(&rset, now);
#endif

32
src/dnsmasq.h
View File

@@ -60,6 +60,7 @@ typedef unsigned long long u64;
#include "dhcp_protocol.h"
#ifdef HAVE_DHCP6
#include "dhcp6_protocol.h"
#include "radv_protocol.h"
#endif
#define gettext_noop(S) (S)
@@ -215,7 +216,8 @@ struct event_desc {
#define OPT_CONSEC_ADDR 34
#define OPT_CONNTRACK 35
#define OPT_FQDN_UPDATE 36
#define OPT_LAST 37
#define OPT_RA 37
#define OPT_LAST 38
/* extra flags for my_syslog, we use a couple of facilities since they are known
not to occupy the same bits as priorities, no matter how syslog.h is set up. */
@@ -605,6 +607,7 @@ struct dhcp_context {
struct in6_addr start6, end6; /* range of available addresses */
struct in6_addr local6;
int prefix;
time_t ra_time;
#endif
int flags;
char *interface;
@@ -616,6 +619,8 @@ struct dhcp_context {
#define CONTEXT_NETMASK 2
#define CONTEXT_BRDCAST 4
#define CONTEXT_PROXY 8
#define CONTEXT_RA_ONLY 16
#define CONTEXT_RA_DONE 32
struct ping_result {
struct in_addr addr;
@@ -694,7 +699,7 @@ extern struct daemon {
int port, query_port, min_port;
unsigned long local_ttl, neg_ttl, max_ttl;
struct hostsfile *addn_hosts;
struct dhcp_context *dhcp, *dhcp6;
struct dhcp_context *dhcp, *dhcp6, *ra_contexts;
struct dhcp_config *dhcp_conf;
struct dhcp_opt *dhcp_opts, *dhcp_match, *dhcp_opts6, *dhcp_match6;
struct dhcp_vendor *dhcp_vendors;
@@ -754,7 +759,7 @@ extern struct daemon {
int duid_len;
unsigned char *duid;
struct iovec outpacket;
int dhcp6fd;
int dhcp6fd, icmp6fd;
#endif
/* DBus stuff */
/* void * here to avoid depending on dbus headers outside dbus.c */
@@ -1054,3 +1059,24 @@ int match_bytes(struct dhcp_opt *o, unsigned char *p, int len);
void dhcp_update_configs(struct dhcp_config *configs);
void check_dhcp_hosts(int fatal);
#endif
/* outpacket.c */
#ifdef HAVE_DHCP6
void end_opt6(int container);
int save_counter(int newval);
void *expand(size_t headroom);
int new_opt6(int opt);
void *put_opt6(void *data, size_t len);
void put_opt6_long(unsigned int val);
void put_opt6_short(unsigned int val);
void put_opt6_char(unsigned int val);
void put_opt6_string(char *s);
#endif
/* radv.c */
#ifdef HAVE_DHCP6
void ra_init(time_t now);
void icmp6_packet(void);
time_t periodic_ra(time_t now);
void ra_start_unsolicted(time_t now);
#endif

10
src/lease.c
View File

@@ -313,7 +313,15 @@ void lease_update_file(time_t now)
}
/* Set alarm for when the first lease expires + slop. */
for (next_event = 0, lease = leases; lease; lease = lease->next)
next_event = 0;
#ifdef HAVE_DHCP6
/* do timed RAs and determine when the next is */
if (option_bool(OPT_RA))
next_event = periodic_ra(now);
#endif
for (lease = leases; lease; lease = lease->next)
if (lease->expires != 0 &&
(next_event == 0 || difftime(next_event, lease->expires + 10) > 0.0))
next_event = lease->expires + 10;

13
src/netlink.c
View File

@@ -284,7 +284,7 @@ int iface_enumerate(int family, void *parm, int (*callback)())
}
if (mac && callback_ok && !((link->ifi_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) &&
!((*callback)((unsigned int)link->ifi_type, mac, maclen, parm)))
!((*callback)((int)link->ifi_index, (unsigned int)link->ifi_type, mac, maclen, parm)))
callback_ok = 0;
}
#endif
@@ -341,6 +341,17 @@ static void nl_routechange(struct nlmsghdr *h)
/* Force re-reading resolv file right now, for luck. */
daemon->last_resolv = 0;
#ifdef HAVE_DHCP6
/* force RAs to sync new network and pick up new interfaces. */
if (option_bool(OPT_RA))
{
ra_start_unsolicted(dnsmasq_time());
/* cause lease_update_file to run after we return, in case we were called from
iface_enumerate and can't re-enter it now */
alarm(1);
}
#endif
if (daemon->srv_save)
{
if (daemon->srv_save->sfd)

22
src/option.c
View File

@@ -114,6 +114,7 @@ struct myoption {
#define LOPT_CONNTRACK 303
#define LOPT_FQDN 304
#define LOPT_LUASCRIPT 305
#define LOPT_RA 306
#ifdef HAVE_GETOPT_LONG
static const struct option opts[] =
@@ -233,6 +234,7 @@ static const struct myoption opts[] =
{ "conntrack", 0, 0, LOPT_CONNTRACK },
{ "dhcp-client-update", 0, 0, LOPT_FQDN },
{ "dhcp-luascript", 1, 0, LOPT_LUASCRIPT },
{ "enable-ra", 0, 0, LOPT_RA },
{ NULL, 0, 0, 0 }
};
@@ -359,6 +361,7 @@ static struct {
{ LOPT_INCR_ADDR, OPT_CONSEC_ADDR, NULL, gettext_noop("Attempt to allocate sequential IP addresses to DHCP clients."), NULL },
{ LOPT_CONNTRACK, OPT_CONNTRACK, NULL, gettext_noop("Copy connection-track mark from queries to upstream connections."), NULL },
{ LOPT_FQDN, OPT_FQDN_UPDATE, NULL, gettext_noop("Allow DHCP clients to do their own DDNS updates."), NULL },
{ LOPT_RA, OPT_RA, NULL, gettext_noop("Send router-advertisements for interfaces doing DHCPv6"), NULL },
{ 0, 0, NULL, NULL, NULL }
};
@@ -2330,17 +2333,32 @@ static char *one_opt(int option, char *arg, char *gen_prob, int command_line)
#ifdef HAVE_DHCP6
else if (inet_pton(AF_INET6, a[0], &new->start6))
{
new->next = daemon->dhcp6;
new->prefix = 64; /* default */
daemon->dhcp6 = new;
if (strcmp(a[1], "static") == 0)
{
memcpy(&new->end6, &new->start6, IN6ADDRSZ);
new->flags |= CONTEXT_STATIC;
}
else if (strcmp(a[1], "ra-only") == 0)
{
memcpy(&new->end6, &new->start6, IN6ADDRSZ);
new->flags |= CONTEXT_RA_ONLY;
}
else if (!inet_pton(AF_INET6, a[1], &new->end6))
option = '?';
if (new->flags & CONTEXT_RA_ONLY)
{
new->next = daemon->ra_contexts;
daemon->ra_contexts = new;
}
else
{
new->next = daemon->dhcp6;
daemon->dhcp6 = new;
}
/* bare integer < 128 is prefix value */
if (option != '?' && k >= 3)
{

108
src/outpacket.c Normal file
View File

@@ -0,0 +1,108 @@
/* dnsmasq is Copyright (c) 2000-2012 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
the Free Software Foundation; version 2 dated June, 1991, or
(at your option) version 3 dated 29 June, 2007.
This 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "dnsmasq.h"
#ifdef HAVE_DHCP6
static size_t outpacket_counter;
void end_opt6(int container)
{
void *p = daemon->outpacket.iov_base + container + 2;
u16 len = outpacket_counter - container - 4 ;
PUTSHORT(len, p);
}
int save_counter(int newval)
{
int ret = outpacket_counter;
if (newval != -1)
outpacket_counter = newval;
return ret;
}
void *expand(size_t headroom)
{
void *ret;
if (expand_buf(&daemon->outpacket, outpacket_counter + headroom))
{
ret = daemon->outpacket.iov_base + outpacket_counter;
outpacket_counter += headroom;
return ret;
}
return NULL;
}
int new_opt6(int opt)
{
int ret = outpacket_counter;
void *p;
if ((p = expand(4)))
{
PUTSHORT(opt, p);
PUTSHORT(0, p);
}
return ret;
}
void *put_opt6(void *data, size_t len)
{
void *p;
if ((p = expand(len)))
memcpy(p, data, len);
return p;
}
void put_opt6_long(unsigned int val)
{
void *p;
if ((p = expand(4)))
PUTLONG(val, p);
}
void put_opt6_short(unsigned int val)
{
void *p;
if ((p = expand(2)))
PUTSHORT(val, p);
}
void put_opt6_char(unsigned int val)
{
unsigned char *p;
if ((p = expand(1)))
*p = val;
}
void put_opt6_string(char *s)
{
put_opt6(s, strlen(s));
}
#endif

433
src/radv.c Normal file
View File

@@ -0,0 +1,433 @@
/* dnsmasq is Copyright (c) 2000-2012 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
the Free Software Foundation; version 2 dated June, 1991, or
(at your option) version 3 dated 29 June, 2007.
This 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* NB. This code may be called during a DHCPv4 transaction which is in ping-wait
It therefore cannot use any DHCP buffer resources except outpacket, which is
not used by DHCPv4 code. */
#include "dnsmasq.h"
#include <netinet/icmp6.h>
#ifdef HAVE_DHCP6
struct ra_param {
int ind, managed, found_context, first;
char *if_name;
struct in6_addr link_local;
};
struct search_param {
time_t now; int iface;
};
static void send_ra(int iface, char *iface_name, struct in6_addr *dest);
static int add_prefixes(struct in6_addr *local, int prefix,
int scope, int if_index, int dad, void *vparam);
static int iface_search(struct in6_addr *local, int prefix,
int scope, int if_index, int dad, void *vparam);
static int add_lla(int index, unsigned int type, char *mac, size_t maclen, void *parm);
static int unicast_hop_limit, multicast_hop_limit;
static time_t ra_short_period_start;
void ra_init(time_t now)
{
struct dhcp_context *context;
struct icmp6_filter filter;
int fd;
#if defined(IP_TOS) && defined(IPTOS_CLASS_CS6)
int class = IPTOS_CLASS_CS6;
#endif
int val = 255; /* radvd uses this value */
size_t len1 = sizeof(int);
size_t len2 = sizeof(int);
ICMP6_FILTER_SETBLOCKALL(&filter);
ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filter);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filter);
if ((fd = socket(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) == -1 ||
getsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &unicast_hop_limit, &len1) ||
getsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &multicast_hop_limit, &len2) ||
#if defined(IP_TOS) && defined(IPTOS_CLASS_CS6)
setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, &class, sizeof(class)) == -1 ||
#endif
!fix_fd(fd) ||
!set_ipv6pktinfo(fd) ||
setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val)) ||
setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val)) ||
setsockopt(fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filter, sizeof(filter)) == -1)
die (_("cannot create ICMPv6 socket: %s"), NULL, EC_BADNET);
daemon->icmp6fd = fd;
/* link the DHCP6 contexts to the ra-only ones so we can traverse them all
from ->ra_contexts, but only the non-ra-onlies from ->dhcp6 */
if (!daemon->ra_contexts)
daemon->ra_contexts = daemon->dhcp6;
else
{
for (context = daemon->ra_contexts; context->next; context = context->next);
context->next = daemon->dhcp6;
}
if (!daemon->dhcp6)
die(_("cannot do router advertisement unless DHCPv6 is enabled"), NULL, EC_BADCONF);
ra_start_unsolicted(now);
}
void ra_start_unsolicted(time_t now)
{
struct dhcp_context *context;
/* init timers so that we do ra's for all soon. some ra_times will end up zeroed
if it's not appropriate to advertise those contexts.
This gets re-called on a netlink route-change to re-do the advertisement
and pick up new interfaces */
/* range 0 - 5 */
for (context = daemon->ra_contexts; context; context = context->next)
context->ra_time = now + (rand16()/13000);
/* re-do ras after a short time, in case the first gets lost.
This is reset once that's done. */
ra_short_period_start = now;
}
void icmp6_packet(void)
{
char interface[IF_NAMESIZE+1];
ssize_t sz;
int if_index = 0;
struct cmsghdr *cmptr;
struct msghdr msg;
union {
struct cmsghdr align; /* this ensures alignment */
char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
} control_u;
struct sockaddr_in6 from;
unsigned char *p;
char *mac = "";
struct iname *tmp;
struct dhcp_context *context;
/* Note: use outpacket for input buffer */
msg.msg_control = control_u.control6;
msg.msg_controllen = sizeof(control_u);
msg.msg_flags = 0;
msg.msg_name = &from;
msg.msg_namelen = sizeof(from);
msg.msg_iov = &daemon->outpacket;
msg.msg_iovlen = 1;
if ((sz = recv_dhcp_packet(daemon->icmp6fd, &msg)) == -1 || sz < 8)
return;
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo)
{
union {
unsigned char *c;
struct in6_pktinfo *p;
} p;
p.c = CMSG_DATA(cmptr);
if_index = p.p->ipi6_ifindex;
}
if (!indextoname(daemon->icmp6fd, if_index, interface))
return;
if (!iface_check(AF_LOCAL, NULL, interface))
return;
for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
if (tmp->name && (strcmp(tmp->name, interface) == 0))
return;
/* weird libvirt-inspired access control */
for (context = daemon->dhcp6; context; context = context->next)
if (!context->interface || strcmp(context->interface, interface) == 0)
break;
if (!context)
return;
p = (unsigned char *)daemon->outpacket.iov_base;
if (p[0] != ICMP6_ROUTER_SOLICIT || p[1] != 0)
return;
/* look for link-layer address option for logging */
if (sz >= 16 && p[8] == ICMP6_OPT_SOURCE_MAC && (p[9] * 8) + 8 <= sz)
{
print_mac(daemon->namebuff, &p[10], (p[9] * 8) - 2);
mac = daemon->namebuff;
}
my_syslog(MS_DHCP | LOG_INFO, "RTR-SOLICIT(%s) %s", interface, mac);
send_ra(if_index, interface, &from.sin6_addr);
}
static void send_ra(int iface, char *iface_name, struct in6_addr *dest)
{
struct ra_packet *ra;
struct ra_param parm;
struct ifreq ifr;
struct sockaddr_in6 addr;
struct dhcp_context *context;
save_counter(0);
ra = expand(sizeof(struct ra_packet));
ra->type = ICMP6_ROUTER_ADVERT;
ra->code = 0;
ra->hop_limit = dest ? unicast_hop_limit : multicast_hop_limit;
ra->flags = 0;
ra->lifetime = htons(1800); /* AdvDefaultLifetime*/
ra->reachable_time = 0;
ra->retrans_time = 0;
parm.ind = iface;
parm.managed = 0;
parm.found_context = 0;
parm.if_name = iface_name;
parm.first = 1;
for (context = daemon->ra_contexts; context; context = context->next)
context->flags &= ~CONTEXT_RA_DONE;
if (!iface_enumerate(AF_INET6, &parm, add_prefixes) ||
!parm.found_context)
return;
strncpy(ifr.ifr_name, iface_name, IF_NAMESIZE);
if (ioctl(daemon->icmp6fd, SIOCGIFMTU, &ifr) != -1)
{
put_opt6_char(ICMP6_OPT_MTU);
put_opt6_char(1);
put_opt6_short(0);
put_opt6_long(ifr.ifr_mtu);
}
iface_enumerate(AF_LOCAL, &iface, add_lla);
/* RDNSS, RFC 6106 */
put_opt6_char(ICMP6_OPT_RDNSS);
put_opt6_char(3);
put_opt6_short(0);
put_opt6_long(1800); /* lifetime - twice RA retransmit */
put_opt6(&parm.link_local, IN6ADDRSZ);
/* set managed bits unless we're providing only RA on this link */
if (parm.managed)
ra->flags = 0xc0;
/* decide where we're sending */
memset(&addr, 0, sizeof(addr));
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(IPPROTO_ICMPV6);
if (dest)
{
memcpy(&addr.sin6_addr, dest, sizeof(struct in6_addr));
if (IN6_IS_ADDR_LINKLOCAL(dest) ||
IN6_IS_ADDR_MC_LINKLOCAL(dest))
addr.sin6_scope_id = iface;
}
else
inet_pton(AF_INET6, ALL_HOSTS, &addr.sin6_addr);
send_from(daemon->icmp6fd, 0, daemon->outpacket.iov_base, save_counter(0),
(union mysockaddr *)&addr, (struct all_addr *)&parm.link_local, iface);
}
static int add_prefixes(struct in6_addr *local, int prefix,
int scope, int if_index, int dad, void *vparam)
{
struct dhcp_context *context, *tmp;
struct ra_param *param = vparam;
struct prefix_opt *opt;
(void)scope; /* warning */
(void)dad;
if (if_index == param->ind)
{
if (IN6_IS_ADDR_LINKLOCAL(local))
param->link_local = *local;
else if (!IN6_IS_ADDR_LOOPBACK(local) &&
!IN6_IS_ADDR_LINKLOCAL(local) &&
!IN6_IS_ADDR_MULTICAST(local))
{
for (context = daemon->ra_contexts; context; context = context->next)
if (prefix == context->prefix &&
is_same_net6(local, &context->start6, prefix) &&
is_same_net6(local, &context->end6, prefix))
{
if (!(context->flags & CONTEXT_RA_ONLY))
param->managed = 1;
if (context->flags & CONTEXT_RA_DONE)
continue;
/* subsequent prefixes on the same interface don't need timers */
if (!param->first)
context->ra_time = 0;
param->first = 0;
param->found_context = 1;
context->flags |= CONTEXT_RA_DONE;
/* mark this subnet and duplicates: as done. */
for (tmp = context->next; tmp; tmp = tmp->next)
if (tmp->prefix == prefix &&
is_same_net6(local, &tmp->start6, prefix) &&
is_same_net6(local, &tmp->end6, prefix))
{
tmp->flags |= CONTEXT_RA_DONE;
context->ra_time = 0;
}
if ((opt = expand(sizeof(struct prefix_opt))))
{
u64 addrpart = addr6part(&context->start6);
u64 mask = (prefix == 64) ? (u64)-1LL : (1LLU << (128 - prefix)) - 1LLU;
unsigned int time = context->lease_time;
/* lifetimes must be min 2 hrs, by RFC 2462 */
if (time < 7200)
time = 7200;
opt->type = ICMP6_OPT_PREFIX;
opt->len = 4;
opt->prefix_len = prefix;
/* autonomous only is we're not doing dhcp */
opt->flags = (context->flags & CONTEXT_RA_ONLY) ? 0xc0 : 0x00;
opt->valid_lifetime = opt->preferred_lifetime = htonl(time);
opt->reserved = 0;
opt->prefix = context->start6;
setaddr6part(&opt->prefix, addrpart & ~mask);
inet_ntop(AF_INET6, &opt->prefix, daemon->addrbuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s", param->if_name, daemon->addrbuff);
}
}
}
}
return 1;
}
static int add_lla(int index, unsigned int type, char *mac, size_t maclen, void *parm)
{
(void)type;
if (index == *((int *)parm))
{
/* size is in units of 8 octets and includes type and length (2 bytes)
add 7 to round up */
int len = (maclen + 9) >> 3;
unsigned char *p = expand(len << 3);
memset(p, 0, len << 3);
*p++ = ICMP6_OPT_SOURCE_MAC;
*p++ = len;
memcpy(p, mac, maclen);
return 0;
}
return 1;
}
time_t periodic_ra(time_t now)
{
struct search_param param;
struct dhcp_context *context;
time_t next_event;
char interface[IF_NAMESIZE+1];
param.now = now;
while (1)
{
/* find overdue events, and time of first future event */
for (next_event = 0, context = daemon->ra_contexts; context; context = context->next)
if (context->ra_time != 0)
{
if (difftime(context->ra_time, now) < 0.0)
break; /* overdue */
if (next_event == 0 || difftime(next_event, context->ra_time + 2) > 0.0)
next_event = context->ra_time + 2;
}
/* none overdue */
if (!context)
break;
/* There's a context overdue, but we can't find an interface
associated with it, because it's for a subnet we dont
have an interface on. Probably we're doing DHCP on
a remote subnet via a relay. Zero the timer, since we won't
ever be able to send ra's and satistfy it. */
if (iface_enumerate(AF_INET6, &param, iface_search))
context->ra_time = 0;
else if (indextoname(daemon->icmp6fd, param.iface, interface))
send_ra(param.iface, interface, NULL);
}
return next_event;
}
static int iface_search(struct in6_addr *local, int prefix,
int scope, int if_index, int dad, void *vparam)
{
struct search_param *param = vparam;
struct dhcp_context *context, *tmp;
(void)scope;
(void)dad;
for (context = daemon->ra_contexts; context; context = context->next)
if (prefix == context->prefix &&
is_same_net6(local, &context->start6, prefix) &&
is_same_net6(local, &context->end6, prefix))
if (context->ra_time != 0 && difftime(context->ra_time, param->now) < 0.0)
{
/* found an interface that's overdue for RA determine new
timeout value and zap other contexts on the same interface
so they don't timeout independently .*/
param->iface = if_index;
if (difftime(param->now, ra_short_period_start) < 60.0)
/* range 5 - 20 */
context->ra_time = param->now + 5 + (rand16()/4400);
else
/* range 450 - 600 */
context->ra_time = param->now + 450 + (rand16()/440);
return 0; /* found, abort */
}
return 1; /* keep searching */
}
#endif

44
src/radv_protocol.h Normal file
View File

@@ -0,0 +1,44 @@
/* dnsmasq is Copyright (c) 2000-2012 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
the Free Software Foundation; version 2 dated June, 1991, or
(at your option) version 3 dated 29 June, 2007.
This 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define ALL_HOSTS "FF02::1"
#define ALL_ROUTERS "FF02::2"
struct ra_packet {
u8 type, code;
u16 checksum;
u8 hop_limit, flags;
u16 lifetime;
u32 reachable_time;
u32 retrans_time;
};
struct prefix_opt {
u8 type, len, prefix_len, flags;
u32 valid_lifetime, preferred_lifetime, reserved;
struct in6_addr prefix;
};
#define ICMP6_ROUTER_SOLICIT 133
#define ICMP6_ROUTER_ADVERT 134
#define ICMP6_OPT_SOURCE_MAC 1
#define ICMP6_OPT_PREFIX 3
#define ICMP6_OPT_MTU 5
#define ICMP6_OPT_RDNSS 25

105
src/rfc3315.c
View File

@@ -19,17 +19,6 @@
#ifdef HAVE_DHCP6
static size_t outpacket_counter;
static void end_opt6(int container);
static int save_counter(int newval);
static void *expand(size_t headroom);
static int new_opt6(int opt);
static void *put_opt6(void *data, size_t len);
static void put_opt6_short(unsigned int val);
static void put_opt6_long(unsigned int val);
static void put_opt6_string(char *s);
static int dhcp6_maybe_relay(struct in6_addr *link_address, struct dhcp_netid **relay_tagsp, struct dhcp_context *context,
int interface, char *iface_name, struct in6_addr *fallback, void *inbuff, size_t sz, int is_unicast, time_t now);
static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dhcp_netid *tags, struct dhcp_context *context,
@@ -55,10 +44,10 @@ size_t dhcp6_reply(struct dhcp_context *context, int interface, char *iface_name
for (vendor = daemon->dhcp_vendors; vendor; vendor = vendor->next)
vendor->netid.next = &vendor->netid;
outpacket_counter = 0;
save_counter(0);
if (dhcp6_maybe_relay(NULL, &relay_tags, context, interface, iface_name, fallback, daemon->dhcp_packet.iov_base, sz, is_unicast, now))
return outpacket_counter;
return save_counter(0);
return 0;
}
@@ -1274,12 +1263,14 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
len += strlen(send_domain) + 1;
o = new_opt6(OPTION6_FQDN);
p = expand(len + 3);
*(p++) = fqdn_flags;
p = do_rfc1035_name(p, hostname);
if (send_domain)
p = do_rfc1035_name(p, send_domain);
*p = 0;
if ((p = expand(len + 3)))
{
*(p++) = fqdn_flags;
p = do_rfc1035_name(p, hostname);
if (send_domain)
p = do_rfc1035_name(p, send_domain);
*p = 0;
}
end_opt6(o);
}
@@ -1422,80 +1413,4 @@ static unsigned int opt6_uint(unsigned char *opt, int offset, int size)
return ret;
}
static void end_opt6(int container)
{
void *p = daemon->outpacket.iov_base + container + 2;
u16 len = outpacket_counter - container - 4 ;
PUTSHORT(len, p);
}
static int save_counter(int newval)
{
int ret = outpacket_counter;
if (newval != -1)
outpacket_counter = newval;
return ret;
}
static void *expand(size_t headroom)
{
void *ret;
if (expand_buf(&daemon->outpacket, outpacket_counter + headroom))
{
ret = daemon->outpacket.iov_base + outpacket_counter;
outpacket_counter += headroom;
return ret;
}
return NULL;
}
static int new_opt6(int opt)
{
int ret = outpacket_counter;
void *p;
if ((p = expand(4)))
{
PUTSHORT(opt, p);
PUTSHORT(0, p);
}
return ret;
}
static void *put_opt6(void *data, size_t len)
{
void *p;
if ((p = expand(len)))
memcpy(p, data, len);
return p;
}
static void put_opt6_long(unsigned int val)
{
void *p;
if ((p = expand(4)))
PUTLONG(val, p);
}
static void put_opt6_short(unsigned int val)
{
void *p;
if ((p = expand(2)))
PUTSHORT(val, p);
}
static void put_opt6_string(char *s)
{
put_opt6(s, strlen(s));
}
#endif