diff options
| -rw-r--r-- | src/libsystemd-network/dhcp-server-internal.h | 6 | ||||
| -rw-r--r-- | src/libsystemd-network/sd-dhcp-server.c | 85 | ||||
| -rw-r--r-- | src/libsystemd-network/test-dhcp-server.c | 27 | ||||
| -rw-r--r-- | src/network/networkd-link.c | 16 | ||||
| -rw-r--r-- | src/systemd/sd-dhcp-server.h | 3 |
5 files changed, 77 insertions, 60 deletions
diff --git a/src/libsystemd-network/dhcp-server-internal.h b/src/libsystemd-network/dhcp-server-internal.h index 268210fc50..5dc3c7aa26 100644 --- a/src/libsystemd-network/dhcp-server-internal.h +++ b/src/libsystemd-network/dhcp-server-internal.h @@ -57,8 +57,9 @@ struct sd_dhcp_server { int ifindex; be32_t address; be32_t netmask; - be32_t pool_start; - size_t pool_size; + be32_t subnet; + uint32_t pool_offset; + uint32_t pool_size; char *timezone; @@ -67,6 +68,7 @@ struct sd_dhcp_server { Hashmap *leases_by_client_id; DHCPLease **bound_leases; + DHCPLease invalid_lease; uint32_t max_lease_time, default_lease_time; }; diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c index 89b9a4c6be..7a8b298b51 100644 --- a/src/libsystemd-network/sd-dhcp-server.c +++ b/src/libsystemd-network/sd-dhcp-server.c @@ -22,6 +22,7 @@ #include <sys/ioctl.h> +#include "in-addr-util.h" #include "siphash24.h" #include "sd-dhcp-server.h" @@ -31,38 +32,63 @@ #define DHCP_DEFAULT_LEASE_TIME_USEC USEC_PER_HOUR #define DHCP_MAX_LEASE_TIME_USEC (USEC_PER_HOUR*12) -int sd_dhcp_server_set_lease_pool(sd_dhcp_server *server, - struct in_addr *address, - size_t size) { +/* configures the server's address and subnet, and optionally the pool's size and offset into the subnet + * the whole pool must fit into the subnet, and may not contain the first (any) nor last (broadcast) address + * moreover, the server's own address may be in the pool, and is in that case reserved in order not to + * accidentally hand it out */ +int sd_dhcp_server_configure_pool(sd_dhcp_server *server, struct in_addr *address, unsigned char prefixlen, uint32_t offset, uint32_t size) { + struct in_addr netmask_addr; + be32_t netmask; + uint32_t server_off, broadcast_off, size_max; + assert_return(server, -EINVAL); assert_return(address, -EINVAL); - assert_return(address->s_addr, -EINVAL); - assert_return(size, -EINVAL); - assert_return(server->pool_start == htobe32(INADDR_ANY), -EBUSY); - assert_return(!server->pool_size, -EBUSY); - assert_return(!server->bound_leases, -EBUSY); + assert_return(address->s_addr != INADDR_ANY, -EINVAL); + assert_return(prefixlen <= 32, -ERANGE); + assert_return(server->address == INADDR_ANY, -EBUSY); + + assert_se(in_addr_prefixlen_to_netmask(&netmask_addr, prefixlen)); + netmask = netmask_addr.s_addr; + + server_off = be32toh(address->s_addr & ~netmask); + broadcast_off = be32toh(~netmask); + + /* the server address cannot be the subnet address */ + assert_return(server_off != 0, -ERANGE); + + /* nor the broadcast address */ + assert_return(server_off != broadcast_off, -ERANGE); + + /* 0 offset means we should set a default, we skip the first (subnet) address + and take the next one */ + if (offset == 0) + offset = 1; + + size_max = (broadcast_off + 1) /* the number of addresses in the subnet */ + - offset /* exclude the addresses before the offset */ + - 1; /* exclude the last (broadcast) address */ + + /* The pool must contain at least one address */ + assert_return(size_max >= 1, -ERANGE); + + if (size != 0) + assert_return(size <= size_max, -ERANGE); + else + size = size_max; server->bound_leases = new0(DHCPLease*, size); if (!server->bound_leases) return -ENOMEM; - server->pool_start = address->s_addr; + server->pool_offset = offset; server->pool_size = size; - return 0; -} - -int sd_dhcp_server_set_address(sd_dhcp_server *server, struct in_addr *address, - unsigned char prefixlen) { - assert_return(server, -EINVAL); - assert_return(address, -EINVAL); - assert_return(address->s_addr, -EINVAL); - assert_return(prefixlen <= 32, -ERANGE); - assert_return(server->address == htobe32(INADDR_ANY), -EBUSY); - assert_return(server->netmask == htobe32(INADDR_ANY), -EBUSY); - server->address = address->s_addr; - server->netmask = htobe32(0xfffffffflu << (32 - prefixlen)); + server->netmask = netmask; + server->subnet = address->s_addr & netmask; + + if (server_off >= offset && server_off - offset < size) + server->bound_leases[server_off - offset] = &server->invalid_lease; return 0; } @@ -661,12 +687,11 @@ static int get_pool_offset(sd_dhcp_server *server, be32_t requested_ip) { if (!server->pool_size) return -EINVAL; - if (be32toh(requested_ip) < be32toh(server->pool_start) || - be32toh(requested_ip) >= be32toh(server->pool_start) + - + server->pool_size) - return -EINVAL; + if (be32toh(requested_ip) < (be32toh(server->subnet) | server->pool_offset) || + be32toh(requested_ip) >= (be32toh(server->subnet) | (server->pool_offset + server->pool_size))) + return -ERANGE; - return be32toh(requested_ip) - be32toh(server->pool_start); + return be32toh(requested_ip & ~server->netmask) - server->pool_offset; } #define HASH_KEY SD_ID128_MAKE(0d,1d,fe,bd,f1,24,bd,b3,47,f1,dd,6e,73,21,93,30) @@ -718,7 +743,7 @@ int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, if (existing_lease) address = existing_lease->address; else { - size_t next_offer; + uint32_t next_offer; /* even with no persistence of leases, we try to offer the same client the same IP address. we do this by using the hash of the client id @@ -728,7 +753,7 @@ int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, for (i = 0; i < server->pool_size; i++) { if (!server->bound_leases[next_offer]) { - address = htobe32(be32toh(server->pool_start) + next_offer); + address = server->subnet | htobe32(server->pool_offset + next_offer); break; } else next_offer = (next_offer + 1) % server->pool_size; @@ -1022,7 +1047,7 @@ int sd_dhcp_server_forcerenew(sd_dhcp_server *server) { for (i = 0; i < server->pool_size; i++) { DHCPLease *lease = server->bound_leases[i]; - if (!lease) + if (!lease || lease == &server->invalid_lease) continue; r = server_send_forcerenew(server, lease->address, diff --git a/src/libsystemd-network/test-dhcp-server.c b/src/libsystemd-network/test-dhcp-server.c index 9f60ab761e..7d8a1f6bd9 100644 --- a/src/libsystemd-network/test-dhcp-server.c +++ b/src/libsystemd-network/test-dhcp-server.c @@ -28,6 +28,14 @@ #include "sd-dhcp-server.h" #include "dhcp-server-internal.h" +static void test_pool(struct in_addr *address, unsigned size, int ret) { + _cleanup_dhcp_server_unref_ sd_dhcp_server *server = NULL; + + assert_se(sd_dhcp_server_new(&server, 1) >= 0); + + assert_se(sd_dhcp_server_configure_pool(server, address, 8, 0, size) == ret); +} + static int test_basic(sd_event *event) { _cleanup_dhcp_server_unref_ sd_dhcp_server *server = NULL; struct in_addr address_lo = { @@ -54,15 +62,14 @@ static int test_basic(sd_event *event) { assert_se(!sd_dhcp_server_unref(server)); assert_se(sd_dhcp_server_start(server) == -EUNATCH); - assert_se(sd_dhcp_server_set_address(server, &address_any, 28) == -EINVAL); - assert_se(sd_dhcp_server_set_address(server, &address_lo, 38) == -ERANGE); - assert_se(sd_dhcp_server_set_address(server, &address_lo, 8) >= 0); - assert_se(sd_dhcp_server_set_address(server, &address_lo, 8) == -EBUSY); - assert_se(sd_dhcp_server_set_lease_pool(server, &address_any, 1) == -EINVAL); - assert_se(sd_dhcp_server_set_lease_pool(server, &address_lo, 0) == -EINVAL); - assert_se(sd_dhcp_server_set_lease_pool(server, &address_lo, 1) >= 0); - assert_se(sd_dhcp_server_set_lease_pool(server, &address_lo, 1) == -EBUSY); + assert_se(sd_dhcp_server_configure_pool(server, &address_any, 28, 0, 0) == -EINVAL); + assert_se(sd_dhcp_server_configure_pool(server, &address_lo, 38, 0, 0) == -ERANGE); + assert_se(sd_dhcp_server_configure_pool(server, &address_lo, 8, 0, 0) >= 0); + assert_se(sd_dhcp_server_configure_pool(server, &address_lo, 8, 0, 0) == -EBUSY); + + test_pool(&address_any, 1, -EINVAL); + test_pool(&address_lo, 1, 0); r = sd_dhcp_server_start(server); @@ -119,12 +126,10 @@ static void test_message_handler(void) { }; assert_se(sd_dhcp_server_new(&server, 1) >= 0); - assert_se(sd_dhcp_server_set_address(server, &address_lo, 8) >= 0); + assert_se(sd_dhcp_server_configure_pool(server, &address_lo, 8, 0, 0) >= 0); assert_se(sd_dhcp_server_attach_event(server, NULL, 0) >= 0); assert_se(sd_dhcp_server_start(server) >= 0); - assert_se(dhcp_server_handle_message(server, (DHCPMessage*)&test, sizeof(test)) == 0); - assert_se(sd_dhcp_server_set_lease_pool(server, &address_lo, 10) >= 0); assert_se(dhcp_server_handle_message(server, (DHCPMessage*)&test, sizeof(test)) == DHCP_OFFER); test.end = 0; diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c index d797a8ded8..74dccfccaf 100644 --- a/src/network/networkd-link.c +++ b/src/network/networkd-link.c @@ -730,7 +730,6 @@ static int link_enter_set_addresses(Link *link) { /* now that we can figure out a default address for the dhcp server, start it */ if (link_dhcp4_server_enabled(link)) { - struct in_addr pool_start; Address *address; Link *uplink = NULL; bool acquired_uplink = false; @@ -742,16 +741,8 @@ static int link_enter_set_addresses(Link *link) { return 0; } - r = sd_dhcp_server_set_address(link->dhcp_server, - &address->in_addr.in, - address->prefixlen); - if (r < 0) - return r; - /* offer 32 addresses starting from the address following the server address */ - pool_start.s_addr = htobe32(be32toh(address->in_addr.in.s_addr) + 1); - r = sd_dhcp_server_set_lease_pool(link->dhcp_server, - &pool_start, 32); + r = sd_dhcp_server_configure_pool(link->dhcp_server, &address->in_addr.in, address->prefixlen, 0, 32); if (r < 0) return r; @@ -760,11 +751,6 @@ static int link_enter_set_addresses(Link *link) { &main_address->in_addr.in); if (r < 0) return r; - - r = sd_dhcp_server_set_prefixlen(link->dhcp_server, - main_address->prefixlen); - if (r < 0) - return r; */ if (link->network->dhcp_server_max_lease_time_usec > 0) { diff --git a/src/systemd/sd-dhcp-server.h b/src/systemd/sd-dhcp-server.h index 7e4f2ffb30..4b0c7a1852 100644 --- a/src/systemd/sd-dhcp-server.h +++ b/src/systemd/sd-dhcp-server.h @@ -44,8 +44,7 @@ bool sd_dhcp_server_is_running(sd_dhcp_server *server); int sd_dhcp_server_start(sd_dhcp_server *server); int sd_dhcp_server_stop(sd_dhcp_server *server); -int sd_dhcp_server_set_address(sd_dhcp_server *server, struct in_addr *address, unsigned char prefixlen); -int sd_dhcp_server_set_lease_pool(sd_dhcp_server *server, struct in_addr *start, size_t size); +int sd_dhcp_server_configure_pool(sd_dhcp_server *server, struct in_addr *address, unsigned char prefixlen, uint32_t offset, uint32_t size); int sd_dhcp_server_set_timezone(sd_dhcp_server *server, const char *timezone); int sd_dhcp_server_set_dns(sd_dhcp_server *server, const struct in_addr ntp[], unsigned n); |