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Update decline address handling in DHCPv6 for new multi-address world.

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When dhcp-host options can have many IPv6 addresses, we need
to deal with one of them being declined by a client. The other
addresses are still valid.

It seems that this logic never worked, even with only one address, since
the DECLINED flag was never tested.
This commit is contained in:
Simon Kelley
2020-03-05 17:10:14 +00:00
parent e39c484ebd
commit c125c1dfee
2 changed files with 48 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/dnsmasq.h
View File

@@ -384,10 +384,12 @@ struct ds_config {
#define ADDRLIST_REVONLY 4
#define ADDRLIST_PREFIX 8
#define ADDRLIST_WILDCARD 16
#define ADDRLIST_DECLINED 32
struct addrlist {
union all_addr addr;
int flags, prefixlen;
int flags, prefixlen;
time_t decline_time;
struct addrlist *next;
};

87
src/rfc3315.c
View File

@@ -49,8 +49,8 @@ static void end_ia(int t1cntr, unsigned int min_time, int do_fuzz);
static void mark_context_used(struct state *state, struct in6_addr *addr);
static void mark_config_used(struct dhcp_context *context, struct in6_addr *addr);
static int check_address(struct state *state, struct in6_addr *addr);
static int config_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr, struct state *state);
static int config_implies(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr);
static int config_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr, struct state *state, time_t now);
static struct addrlist *config_implies(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr);
static void add_address(struct state *state, struct dhcp_context *context, unsigned int lease_time, void *ia_option,
unsigned int *min_time, struct in6_addr *addr, time_t now);
static void update_leases(struct state *state, struct dhcp_context *context, struct in6_addr *addr, unsigned int lease_time, time_t now);
@@ -679,7 +679,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
/* If the client asks for an address on the same network as a configured address,
offer the configured address instead, to make moving to newly-configured
addresses automatic. */
if (!(c->flags & CONTEXT_CONF_USED) && config_valid(config, c, &addr, state))
if (!(c->flags & CONTEXT_CONF_USED) && config_valid(config, c, &addr, state, now))
{
req_addr = addr;
mark_config_used(c, &addr);
@@ -703,7 +703,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
for (c = state->context; c; c = c->current)
if (!(c->flags & CONTEXT_CONF_USED) &&
match_netid(c->filter, solicit_tags, plain_range) &&
config_valid(config, c, &addr, state))
config_valid(config, c, &addr, state, now))
{
mark_config_used(state->context, &addr);
if (have_config(config, CONFIG_TIME))
@@ -847,7 +847,7 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
memcpy(&req_addr, opt6_ptr(ia_option, 0), IN6ADDRSZ);
if ((c = address6_valid(state->context, &req_addr, tagif, 1)))
config_ok = config_implies(config, c, &req_addr);
config_ok = (config_implies(config, c, &req_addr) != NULL);
if ((dynamic = address6_available(state->context, &req_addr, tagif, 1)) || c)
{
@@ -1186,18 +1186,19 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
{
struct dhcp_lease *lease;
struct in6_addr addr;
struct addrlist *addr_list;
/* align */
memcpy(&addr, opt6_ptr(ia_option, 0), IN6ADDRSZ);
if (have_config(config, CONFIG_ADDR6) && IN6_ARE_ADDR_EQUAL(&config->addr6, &addr))
if ((addr_list = config_implies(config, state->context, &addr)))
{
prettyprint_time(daemon->dhcp_buff3, DECLINE_BACKOFF);
inet_ntop(AF_INET6, &addr, daemon->addrbuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_WARNING, _("disabling DHCP static address %s for %s"),
daemon->addrbuff, daemon->dhcp_buff3);
config->flags |= CONFIG_DECLINED;
config->decline_time = now;
addr_list->flags |= ADDRLIST_DECLINED;
addr_list->decline_time = now;
}
else
/* make sure this host gets a different address next time. */
@@ -1669,14 +1670,14 @@ static int check_address(struct state *state, struct in6_addr *addr)
/* return true of *addr could have been generated from config. */
static int config_implies(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr)
static struct addrlist *config_implies(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr)
{
int prefix;
struct in6_addr wild_addr;
struct addrlist *addr_list;
if (!config || !(config->flags & CONFIG_ADDR6))
return 0;
return NULL;
for (addr_list = config->addr6; addr_list; addr_list = addr_list->next)
{
@@ -1692,13 +1693,13 @@ static int config_implies(struct dhcp_config *config, struct dhcp_context *conte
continue;
if (is_same_net6(&wild_addr, addr, prefix))
return 1;
return addr_list;
}
return 0;
return NULL;
}
static int config_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr, struct state *state)
static int config_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr, struct state *state, time_t now)
{
u64 addrpart, i, addresses;
struct addrlist *addr_list;
@@ -1707,34 +1708,36 @@ static int config_valid(struct dhcp_config *config, struct dhcp_context *context
return 0;
for (addr_list = config->addr6; addr_list; addr_list = addr_list->next)
{
addrpart = addr6part(&addr_list->addr.addr6);
addresses = 1;
if (addr_list->flags & ADDRLIST_PREFIX)
addresses = 1<<(128-addr_list->prefixlen);
if ((addr_list->flags & ADDRLIST_WILDCARD))
{
if (context->prefix != 64)
continue;
*addr = context->start6;
}
else if (is_same_net6(&context->start6, &addr_list->addr.addr6, context->prefix))
*addr = addr_list->addr.addr6;
else
continue;
for (i = 0 ; i < addresses; i++)
{
setaddr6part(addr, addrpart+i);
if (check_address(state, addr))
return 1;
}
}
if (!(addr_list->flags && ADDRLIST_DECLINED) ||
difftime(now, addr_list->decline_time) >= (float)DECLINE_BACKOFF)
{
addrpart = addr6part(&addr_list->addr.addr6);
addresses = 1;
if (addr_list->flags & ADDRLIST_PREFIX)
addresses = 1<<(128-addr_list->prefixlen);
if ((addr_list->flags & ADDRLIST_WILDCARD))
{
if (context->prefix != 64)
continue;
*addr = context->start6;
}
else if (is_same_net6(&context->start6, &addr_list->addr.addr6, context->prefix))
*addr = addr_list->addr.addr6;
else
continue;
for (i = 0 ; i < addresses; i++)
{
setaddr6part(addr, addrpart+i);
if (check_address(state, addr))
return 1;
}
}
return 0;
}