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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

2
src/dnsmasq.h
View File

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

29
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_context_used(struct state *state, struct in6_addr *addr);
static void mark_config_used(struct dhcp_context *context, 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 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_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr, struct state *state, time_t now);
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);
static void add_address(struct state *state, struct dhcp_context *context, unsigned int lease_time, void *ia_option, 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); 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); 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, /* 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 offer the configured address instead, to make moving to newly-configured
addresses automatic. */ 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; req_addr = addr;
mark_config_used(c, &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) for (c = state->context; c; c = c->current)
if (!(c->flags & CONTEXT_CONF_USED) && if (!(c->flags & CONTEXT_CONF_USED) &&
match_netid(c->filter, solicit_tags, plain_range) && 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); mark_config_used(state->context, &addr);
if (have_config(config, CONFIG_TIME)) 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); memcpy(&req_addr, opt6_ptr(ia_option, 0), IN6ADDRSZ);
if ((c = address6_valid(state->context, &req_addr, tagif, 1))) 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) 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 dhcp_lease *lease;
struct in6_addr addr; struct in6_addr addr;
struct addrlist *addr_list;
/* align */ /* align */
memcpy(&addr, opt6_ptr(ia_option, 0), IN6ADDRSZ); 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); prettyprint_time(daemon->dhcp_buff3, DECLINE_BACKOFF);
inet_ntop(AF_INET6, &addr, daemon->addrbuff, ADDRSTRLEN); inet_ntop(AF_INET6, &addr, daemon->addrbuff, ADDRSTRLEN);
my_syslog(MS_DHCP | LOG_WARNING, _("disabling DHCP static address %s for %s"), my_syslog(MS_DHCP | LOG_WARNING, _("disabling DHCP static address %s for %s"),
daemon->addrbuff, daemon->dhcp_buff3); daemon->addrbuff, daemon->dhcp_buff3);
config->flags |= CONFIG_DECLINED; addr_list->flags |= ADDRLIST_DECLINED;
config->decline_time = now; addr_list->decline_time = now;
} }
else else
/* make sure this host gets a different address next time. */ /* 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. */ /* 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; int prefix;
struct in6_addr wild_addr; struct in6_addr wild_addr;
struct addrlist *addr_list; struct addrlist *addr_list;
if (!config || !(config->flags & CONFIG_ADDR6)) if (!config || !(config->flags & CONFIG_ADDR6))
return 0; return NULL;
for (addr_list = config->addr6; addr_list; addr_list = addr_list->next) 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; continue;
if (is_same_net6(&wild_addr, addr, prefix)) 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; u64 addrpart, i, addresses;
struct addrlist *addr_list; struct addrlist *addr_list;
@@ -1707,6 +1708,8 @@ static int config_valid(struct dhcp_config *config, struct dhcp_context *context
return 0; return 0;
for (addr_list = config->addr6; addr_list; addr_list = addr_list->next) for (addr_list = config->addr6; addr_list; addr_list = addr_list->next)
if (!(addr_list->flags && ADDRLIST_DECLINED) ||
difftime(now, addr_list->decline_time) >= (float)DECLINE_BACKOFF)
{ {
addrpart = addr6part(&addr_list->addr.addr6); addrpart = addr6part(&addr_list->addr.addr6);
addresses = 1; addresses = 1;