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Advertise lost prefixes with pref_time == 0 for 2 hours.

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This commit is contained in:
Simon Kelley
2013-07-26 13:59:03 +01:00
parent d9fb0be8c7
commit ef1a94abaa
7 changed files with 154 additions and 49 deletions
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8
CHANGELOG
View File

@@ -71,6 +71,14 @@ version 2.67
Make --clear-on-reload apply to setting upstream servers
via DBus too.
When the address which triggered the construction of an
advertised IPv6 prefix disappears, continue to advertise
the prefix for up to 2 hours, with the preferred lifetime
set to zero. This satisfies RFC 6204 4.3 L-13 and makes
things work better if a prefix disappears without being
deprecated first. Thanks to Uwe Schindler for persuasively
arguing for this.
version 2.66
Add the ability to act as an authoritative DNS

9
src/dhcp-common.c
View File

@@ -720,7 +720,7 @@ void log_context(int family, struct dhcp_context *context)
p += sprintf(p, ", ");
if (indextoname(daemon->doing_dhcp6 ? daemon->dhcp6fd : daemon->icmp6fd, context->if_index, ifrn_name))
sprintf(p, "constructed for %s", ifrn_name);
sprintf(p, "%s for %s", (context->flags & CONTEXT_OLD) ? "old prefix" : "constructed", ifrn_name);
}
else if (context->flags & CONTEXT_TEMPLATE)
{
@@ -731,7 +731,8 @@ void log_context(int family, struct dhcp_context *context)
}
#endif
if ((context->flags & CONTEXT_DHCP) || family == AF_INET)
if (!(context->flags & CONTEXT_OLD) &&
((context->flags & CONTEXT_DHCP) || family == AF_INET))
{
inet_ntop(family, start, daemon->dhcp_buff, 256);
inet_ntop(family, end, daemon->dhcp_buff3, 256);
@@ -748,9 +749,9 @@ void log_context(int family, struct dhcp_context *context)
}
#ifdef HAVE_DHCP6
if (context->flags & CONTEXT_RA_NAME)
if ((context->flags & CONTEXT_RA_NAME) && !(context->flags & CONTEXT_OLD))
my_syslog(MS_DHCP | LOG_INFO, _("DHCPv4-derived IPv6 names on %s%s"), daemon->addrbuff, template);
if ((context->flags & CONTEXT_RA) || (option_bool(OPT_RA) && (context->flags & CONTEXT_DHCP) && family == AF_INET6))
my_syslog(MS_DHCP | LOG_INFO, _("router advertisement on %s%s"), daemon->addrbuff, template);
#endif

56
src/dhcp6.c
View File

@@ -220,7 +220,7 @@ static int complete_context6(struct in6_addr *local, int prefix,
for (context = daemon->dhcp6; context; context = context->next)
{
if ((context->flags & CONTEXT_DHCP) &&
!(context->flags & CONTEXT_TEMPLATE) &&
!(context->flags & (CONTEXT_TEMPLATE | CONTEXT_OLD)) &&
prefix == context->prefix &&
is_same_net6(local, &context->start6, prefix) &&
is_same_net6(local, &context->end6, prefix))
@@ -552,7 +552,10 @@ static int construct_worker(struct in6_addr *local, int prefix,
IN6_ARE_ADDR_EQUAL(&start6, &context->start6) &&
IN6_ARE_ADDR_EQUAL(&end6, &context->end6))
{
context->flags &= ~CONTEXT_GC;
int flags = context->flags;
context->flags &= ~(CONTEXT_GC | CONTEXT_OLD);
if (flags & CONTEXT_OLD)
log_context(AF_INET6, context);
break;
}
@@ -565,6 +568,7 @@ static int construct_worker(struct in6_addr *local, int prefix,
context->flags |= CONTEXT_CONSTRUCTED;
context->if_index = if_index;
context->local6 = *local;
context->saved_valid = 0;
context->next = daemon->dhcp6;
daemon->dhcp6 = context;
@@ -587,35 +591,53 @@ static int construct_worker(struct in6_addr *local, int prefix,
void dhcp_construct_contexts(time_t now)
{
struct dhcp_context *tmp, *context, **up;
struct dhcp_context *context, *tmp, **up;
struct cparam param;
param.newone = 0;
param.newname = 0;
param.now = now;
for (context = daemon->dhcp6; context; context = context->next)
{
context->if_index = 0;
if (context->flags & CONTEXT_CONSTRUCTED)
context->flags |= CONTEXT_GC;
}
if (context->flags & CONTEXT_CONSTRUCTED)
context->flags |= CONTEXT_GC;
iface_enumerate(AF_INET6, &param, construct_worker);
for (up = &daemon->dhcp6, context = daemon->dhcp6; context; context = tmp)
{
tmp = context->next;
if (context->flags & CONTEXT_GC)
tmp = context->next;
if (context->flags & CONTEXT_GC && !(context->flags & CONTEXT_OLD))
{
*up = context->next;
param.newone = 1; /* include deletion */
if (context->flags & CONTEXT_RA_NAME)
param.newname = 1;
free(context);
if ((context->flags & (CONTEXT_RA_ONLY | CONTEXT_RA_NAME | CONTEXT_RA_STATELESS)) ||
option_bool(OPT_RA))
{
/* previously constructed context has gone. advertise it's demise */
context->flags |= CONTEXT_OLD;
context->address_lost_time = now;
if (context->saved_valid > 7200) /* 2 hours */
context->saved_valid = 7200;
ra_start_unsolicted(now, context);
param.newone = 1; /* include deletion */
if (context->flags & CONTEXT_RA_NAME)
param.newname = 1;
log_context(AF_INET6, context);
up = &context->next;
}
else
{
/* we were never doing RA for this, so free now */
*up = context->next;
free(context);
}
}
else
up = &context->next;
up = &context->next;
}
if (param.newone)

6
src/dnsmasq.h
View File

@@ -706,8 +706,8 @@ struct dhcp_context {
struct in6_addr start6, end6; /* range of available addresses */
struct in6_addr local6;
int prefix, if_index;
unsigned int valid, preferred;
time_t ra_time, ra_short_period_start;
unsigned int valid, preferred, saved_valid;
time_t ra_time, ra_short_period_start, address_lost_time;
char *template_interface;
#endif
int flags;
@@ -732,6 +732,8 @@ struct dhcp_context {
#define CONTEXT_CONF_USED 16384
#define CONTEXT_USED 32768
#define CONTEXT_NOAUTH 65536
#define CONTEXT_OLD 131072
struct ping_result {
struct in_addr addr;

116
src/radv.c
View File

@@ -47,6 +47,7 @@ static int iface_search(struct in6_addr *local, int prefix,
int scope, int if_index, int flags,
int prefered, int valid, void *vparam);
static int add_lla(int index, unsigned int type, char *mac, size_t maclen, void *parm);
static void new_timeout(struct dhcp_context *context, time_t now);
static int hop_limit;
@@ -187,9 +188,8 @@ static void send_ra(time_t now, int iface, char *iface_name, struct in6_addr *de
{
struct ra_packet *ra;
struct ra_param parm;
struct ifreq ifr;
struct sockaddr_in6 addr;
struct dhcp_context *context;
struct dhcp_context *context, *tmp, **up;
struct dhcp_netid iface_id;
struct dhcp_opt *opt_cfg;
int done_dns = 0;
@@ -228,12 +228,66 @@ static void send_ra(time_t now, int iface, char *iface_name, struct in6_addr *de
context->netid.next = &context->netid;
}
if (!iface_enumerate(AF_INET6, &parm, add_prefixes) ||
!parm.found_context)
if (!iface_enumerate(AF_INET6, &parm, add_prefixes))
return;
strncpy(ifr.ifr_name, iface_name, IF_NAMESIZE);
/* Look for constructed contexts associated with addresses which have gone,
and advertise them with preferred_time == 0 RFC 6204 4.3 L-13 */
for (up = &daemon->dhcp6, context = daemon->dhcp6; context; context = tmp)
{
tmp = context->next;
if (context->if_index == iface && (context->flags & CONTEXT_OLD))
{
unsigned int old = difftime(now, context->address_lost_time);
if (old > context->saved_valid)
{
/* We've advertised this enough, time to go */
*up = context->next;
free(context);
}
else
{
struct prefix_opt *opt;
struct in6_addr local = context->start6;
int do_slaac = 0;
parm.found_context = 1;
/* zero net part of address */
setaddr6part(&local, addr6part(&local) & ~((context->prefix == 64) ? (u64)-1LL : (1LLU << (128 - context->prefix)) - 1LLU));
if ((context->flags &
(CONTEXT_RA_ONLY | CONTEXT_RA_NAME | CONTEXT_RA_STATELESS)))
do_slaac = 1;
if ((opt = expand(sizeof(struct prefix_opt))))
{
opt->type = ICMP6_OPT_PREFIX;
opt->len = 4;
opt->prefix_len = context->prefix;
/* autonomous only if we're not doing dhcp, always set "on-link" */
opt->flags = do_slaac ? 0xC0 : 0x80;
opt->valid_lifetime = htonl(context->saved_valid - old);
opt->preferred_lifetime = htonl(0);
opt->reserved = 0;
opt->prefix = local;
inet_ntop(AF_INET6, &local, daemon->addrbuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s old prefix", iface_name, daemon->addrbuff);
}
up = &context->next;
}
}
else
up = &context->next;
}
if (!parm.found_context)
return;
#ifdef HAVE_LINUX_NETWORK
/* Note that IPv6 MTU is not necessarilly the same as the IPv4 MTU
available from SIOCGIFMTU */
@@ -361,11 +415,13 @@ static int add_prefixes(struct in6_addr *local, int prefix,
struct dhcp_context *context;
for (context = daemon->dhcp6; context; context = context->next)
if (!(context->flags & CONTEXT_TEMPLATE) &&
if (!(context->flags & (CONTEXT_TEMPLATE | CONTEXT_OLD)) &&
prefix == context->prefix &&
is_same_net6(local, &context->start6, prefix) &&
is_same_net6(local, &context->end6, prefix))
{
context->saved_valid = valid;
if ((context->flags &
(CONTEXT_RA_ONLY | CONTEXT_RA_NAME | CONTEXT_RA_STATELESS)))
{
@@ -466,6 +522,7 @@ static int add_prefixes(struct in6_addr *local, int prefix,
inet_ntop(AF_INET6, local, daemon->addrbuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_INFO, "RTR-ADVERT(%s) %s", param->if_name, daemon->addrbuff);
}
}
}
}
@@ -520,16 +577,25 @@ time_t periodic_ra(time_t now)
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))
if ((context->flags & CONTEXT_OLD) && context->if_index != 0)
{
/* A context for an old address. We'll not find the interface by
looking for addresses, but we know it anyway, as long as we
sent at least one RA whilst the address was current. */
param.iface = context->if_index;
new_timeout(context, now);
}
else if (iface_enumerate(AF_INET6, &param, iface_search))
/* 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. */
context->ra_time = 0;
else if (param.iface != 0 &&
indextoname(daemon->icmp6fd, param.iface, interface) &&
iface_check(AF_LOCAL, NULL, interface, NULL))
if (param.iface != 0 &&
indextoname(daemon->icmp6fd, param.iface, interface) &&
iface_check(AF_LOCAL, NULL, interface, NULL))
{
struct iname *tmp;
for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
@@ -554,7 +620,7 @@ static int iface_search(struct in6_addr *local, int prefix,
(void)valid;
for (context = daemon->dhcp6; context; context = context->next)
if (!(context->flags & CONTEXT_TEMPLATE) &&
if (!(context->flags & (CONTEXT_TEMPLATE | CONTEXT_OLD)) &&
prefix == context->prefix &&
is_same_net6(local, &context->start6, prefix) &&
is_same_net6(local, &context->end6, prefix) &&
@@ -568,12 +634,7 @@ static int iface_search(struct in6_addr *local, int prefix,
if (!(flags & IFACE_TENTATIVE))
param->iface = if_index;
if (difftime(param->now, context->ra_short_period_start) < 60.0)
/* range 5 - 20 */
context->ra_time = param->now + 5 + (rand16()/4400);
else
/* range 3/4 - 1 times RA_INTERVAL */
context->ra_time = param->now + (3 * RA_INTERVAL)/4 + ((RA_INTERVAL * (unsigned int)rand16()) >> 18);
new_timeout(context, param->now);
/* zero timers for other contexts on the same subnet, so they don't timeout
independently */
@@ -588,6 +649,15 @@ static int iface_search(struct in6_addr *local, int prefix,
return 1; /* keep searching */
}
static void new_timeout(struct dhcp_context *context, time_t now)
{
if (difftime(now, context->ra_short_period_start) < 60.0)
/* range 5 - 20 */
context->ra_time = now + 5 + (rand16()/4400);
else
/* range 3/4 - 1 times RA_INTERVAL */
context->ra_time = now + (3 * RA_INTERVAL)/4 + ((RA_INTERVAL * (unsigned int)rand16()) >> 18);
}
#endif

2
src/rfc3315.c
View File

@@ -120,7 +120,7 @@ static int dhcp6_maybe_relay(struct in6_addr *link_address, struct dhcp_netid **
!IN6_IS_ADDR_MULTICAST(link_address))
for (c = daemon->dhcp6; c; c = c->next)
if ((c->flags & CONTEXT_DHCP) &&
!(c->flags & CONTEXT_TEMPLATE) &&
!(c->flags & (CONTEXT_TEMPLATE | CONTEXT_OLD)) &&
is_same_net6(link_address, &c->start6, c->prefix) &&
is_same_net6(link_address, &c->end6, c->prefix))
{

6
src/slaac.c
View File

@@ -38,7 +38,9 @@ void slaac_add_addrs(struct dhcp_lease *lease, time_t now, int force)
lease->slaac_address = NULL;
for (context = daemon->dhcp6; context; context = context->next)
if ((context->flags & CONTEXT_RA_NAME) && lease->last_interface == context->if_index)
if ((context->flags & CONTEXT_RA_NAME) &&
!(context->flags & CONTEXT_OLD) &&
lease->last_interface == context->if_index)
{
struct in6_addr addr = context->start6;
if (lease->hwaddr_len == 6 &&
@@ -123,7 +125,7 @@ time_t periodic_slaac(time_t now, struct dhcp_lease *leases)
time_t next_event = 0;
for (context = daemon->dhcp6; context; context = context->next)
if ((context->flags & CONTEXT_RA_NAME))
if ((context->flags & CONTEXT_RA_NAME) && !(context->flags & CONTEXT_OLD))
break;
/* nothing configured */