diff options
Diffstat (limited to 'src/network/netdev/l2tp-tunnel.c')
| -rw-r--r-- | src/network/netdev/l2tp-tunnel.c | 728 |
1 files changed, 728 insertions, 0 deletions
diff --git a/src/network/netdev/l2tp-tunnel.c b/src/network/netdev/l2tp-tunnel.c new file mode 100644 index 0000000..eeea197 --- /dev/null +++ b/src/network/netdev/l2tp-tunnel.c @@ -0,0 +1,728 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <netinet/in.h> +#include <linux/l2tp.h> +#include <linux/genetlink.h> + +#include "conf-parser.h" +#include "hashmap.h" +#include "l2tp-tunnel.h" +#include "netlink-util.h" +#include "networkd-address.h" +#include "networkd-manager.h" +#include "parse-util.h" +#include "socket-util.h" +#include "string-table.h" +#include "string-util.h" +#include "util.h" + +static const char* const l2tp_l2spec_type_table[_NETDEV_L2TP_L2SPECTYPE_MAX] = { + [NETDEV_L2TP_L2SPECTYPE_NONE] = "none", + [NETDEV_L2TP_L2SPECTYPE_DEFAULT] = "default", +}; + +DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(l2tp_l2spec_type, L2tpL2specType); + +static const char* const l2tp_encap_type_table[_NETDEV_L2TP_ENCAPTYPE_MAX] = { + [NETDEV_L2TP_ENCAPTYPE_UDP] = "udp", + [NETDEV_L2TP_ENCAPTYPE_IP] = "ip", +}; + +DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(l2tp_encap_type, L2tpEncapType); +DEFINE_CONFIG_PARSE_ENUM(config_parse_l2tp_encap_type, l2tp_encap_type, L2tpEncapType, "Failed to parse L2TP Encapsulation Type"); + +static const char* const l2tp_local_address_type_table[_NETDEV_L2TP_LOCAL_ADDRESS_MAX] = { + [NETDEV_L2TP_LOCAL_ADDRESS_AUTO] = "auto", + [NETDEV_L2TP_LOCAL_ADDRESS_STATIC] = "static", + [NETDEV_L2TP_LOCAL_ADDRESS_DYNAMIC] = "dynamic", +}; + +DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(l2tp_local_address_type, L2tpLocalAddressType); + +static void l2tp_session_free(L2tpSession *s) { + if (!s) + return; + + if (s->tunnel && s->section) + ordered_hashmap_remove(s->tunnel->sessions_by_section, s->section); + + network_config_section_free(s->section); + + free(s->name); + + free(s); +} + +DEFINE_NETWORK_SECTION_FUNCTIONS(L2tpSession, l2tp_session_free); + +static int l2tp_session_new_static(L2tpTunnel *t, const char *filename, unsigned section_line, L2tpSession **ret) { + _cleanup_(network_config_section_freep) NetworkConfigSection *n = NULL; + _cleanup_(l2tp_session_freep) L2tpSession *s = NULL; + int r; + + assert(t); + assert(ret); + assert(filename); + assert(section_line > 0); + + r = network_config_section_new(filename, section_line, &n); + if (r < 0) + return r; + + s = ordered_hashmap_get(t->sessions_by_section, n); + if (s) { + *ret = TAKE_PTR(s); + return 0; + } + + s = new(L2tpSession, 1); + if (!s) + return -ENOMEM; + + *s = (L2tpSession) { + .l2tp_l2spec_type = NETDEV_L2TP_L2SPECTYPE_DEFAULT, + .tunnel = t, + .section = TAKE_PTR(n), + }; + + r = ordered_hashmap_ensure_allocated(&t->sessions_by_section, &network_config_hash_ops); + if (r < 0) + return r; + + r = ordered_hashmap_put(t->sessions_by_section, s->section, s); + if (r < 0) + return r; + + *ret = TAKE_PTR(s); + return 0; +} + +static int netdev_l2tp_fill_message_tunnel(NetDev *netdev, union in_addr_union *local_address, sd_netlink_message **ret) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + uint16_t encap_type; + L2tpTunnel *t; + int r; + + assert(netdev); + assert(local_address); + + t = L2TP(netdev); + + assert(t); + + r = sd_genl_message_new(netdev->manager->genl, SD_GENL_L2TP, L2TP_CMD_TUNNEL_CREATE, &m); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Failed to create generic netlink message: %m"); + + r = sd_netlink_message_append_u32(m, L2TP_ATTR_CONN_ID, t->tunnel_id); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_CONN_ID attribute: %m"); + + r = sd_netlink_message_append_u32(m, L2TP_ATTR_PEER_CONN_ID, t->peer_tunnel_id); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_PEER_CONN_ID attribute: %m"); + + r = sd_netlink_message_append_u8(m, L2TP_ATTR_PROTO_VERSION, 3); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_PROTO_VERSION attribute: %m"); + + switch(t->l2tp_encap_type) { + case NETDEV_L2TP_ENCAPTYPE_IP: + encap_type = L2TP_ENCAPTYPE_IP; + break; + case NETDEV_L2TP_ENCAPTYPE_UDP: + default: + encap_type = L2TP_ENCAPTYPE_UDP; + break; + } + + r = sd_netlink_message_append_u16(m, L2TP_ATTR_ENCAP_TYPE, encap_type); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_ENCAP_TYPE attribute: %m"); + + if (t->family == AF_INET) { + r = sd_netlink_message_append_in_addr(m, L2TP_ATTR_IP_SADDR, &local_address->in); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_IP_SADDR attribute: %m"); + + r = sd_netlink_message_append_in_addr(m, L2TP_ATTR_IP_DADDR, &t->remote.in); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_IP_DADDR attribute: %m"); + } else { + r = sd_netlink_message_append_in6_addr(m, L2TP_ATTR_IP6_SADDR, &local_address->in6); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_IP6_SADDR attribute: %m"); + + r = sd_netlink_message_append_in6_addr(m, L2TP_ATTR_IP6_DADDR, &t->remote.in6); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_IP6_DADDR attribute: %m"); + } + + if (encap_type == L2TP_ENCAPTYPE_UDP) { + r = sd_netlink_message_append_u16(m, L2TP_ATTR_UDP_SPORT, t->l2tp_udp_sport); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_UDP_SPORT, attribute: %m"); + + r = sd_netlink_message_append_u16(m, L2TP_ATTR_UDP_DPORT, t->l2tp_udp_dport); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_UDP_DPORT attribute: %m"); + + if (t->udp_csum) { + r = sd_netlink_message_append_u8(m, L2TP_ATTR_UDP_CSUM, t->udp_csum); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_UDP_CSUM attribute: %m"); + } + + if (t->udp6_csum_tx) { + r = sd_netlink_message_append_flag(m, L2TP_ATTR_UDP_ZERO_CSUM6_TX); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_UDP_ZERO_CSUM6_TX attribute: %m"); + } + + if (t->udp6_csum_rx) { + r = sd_netlink_message_append_flag(m, L2TP_ATTR_UDP_ZERO_CSUM6_RX); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_UDP_ZERO_CSUM6_RX attribute: %m"); + } + } + + *ret = TAKE_PTR(m); + + return 0; +} + +static int netdev_l2tp_fill_message_session(NetDev *netdev, L2tpSession *session, sd_netlink_message **ret) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + uint16_t l2_spec_len; + uint8_t l2_spec_type; + int r; + + assert(netdev); + assert(session); + assert(session->tunnel); + + r = sd_genl_message_new(netdev->manager->genl, SD_GENL_L2TP, L2TP_CMD_SESSION_CREATE, &m); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Failed to create generic netlink message: %m"); + + r = sd_netlink_message_append_u32(m, L2TP_ATTR_CONN_ID, session->tunnel->tunnel_id); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_CONN_ID attribute: %m"); + + r = sd_netlink_message_append_u32(m, L2TP_ATTR_PEER_CONN_ID, session->tunnel->peer_tunnel_id); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_PEER_CONN_ID attribute: %m"); + + r = sd_netlink_message_append_u32(m, L2TP_ATTR_SESSION_ID, session->session_id); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_SESSION_ID attribute: %m"); + + r = sd_netlink_message_append_u32(m, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_PEER_SESSION_ID attribute: %m"); + + r = sd_netlink_message_append_u16(m, L2TP_ATTR_PW_TYPE, L2TP_PWTYPE_ETH); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_PW_TYPE attribute: %m"); + + switch (session->l2tp_l2spec_type) { + case NETDEV_L2TP_L2SPECTYPE_NONE: + l2_spec_type = L2TP_L2SPECTYPE_NONE; + l2_spec_len = 0; + break; + case NETDEV_L2TP_L2SPECTYPE_DEFAULT: + default: + l2_spec_type = L2TP_L2SPECTYPE_DEFAULT; + l2_spec_len = 4; + break; + } + + r = sd_netlink_message_append_u8(m, L2TP_ATTR_L2SPEC_TYPE, l2_spec_type); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_L2SPEC_TYPE attribute: %m"); + + r = sd_netlink_message_append_u8(m, L2TP_ATTR_L2SPEC_LEN, l2_spec_len); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_L2SPEC_LEN attribute: %m"); + + r = sd_netlink_message_append_string(m, L2TP_ATTR_IFNAME, session->name); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not append L2TP_ATTR_IFNAME attribute: %m"); + + *ret = TAKE_PTR(m); + + return 0; +} + +static int l2tp_acquire_local_address_one(L2tpTunnel *t, Address *a, union in_addr_union *ret) { + if (a->family != t->family) + return -EINVAL; + + if (in_addr_is_null(a->family, &a->in_addr_peer) <= 0) + return -EINVAL; + + if (t->local_address_type == NETDEV_L2TP_LOCAL_ADDRESS_STATIC && + !FLAGS_SET(a->flags, IFA_F_PERMANENT)) + return -EINVAL; + + if (t->local_address_type == NETDEV_L2TP_LOCAL_ADDRESS_DYNAMIC && + FLAGS_SET(a->flags, IFA_F_PERMANENT)) + return -EINVAL; + + *ret = a->in_addr; + return 0; +} + +static int l2tp_acquire_local_address(L2tpTunnel *t, Link *link, union in_addr_union *ret) { + Address *a; + + assert(t); + assert(link); + assert(ret); + assert(IN_SET(t->family, AF_INET, AF_INET6)); + + if (!in_addr_is_null(t->family, &t->local)) { + /* local address is explicitly specified. */ + *ret = t->local; + return 0; + } + + SET_FOREACH(a, link->addresses) + if (l2tp_acquire_local_address_one(t, a, ret) >= 0) + return 1; + + SET_FOREACH(a, link->addresses_foreign) + if (l2tp_acquire_local_address_one(t, a, ret) >= 0) + return 1; + + return -ENODATA; +} + +static void l2tp_session_destroy_callback(L2tpSession *session) { + if (!session) + return; + + netdev_unref(NETDEV(session->tunnel)); +} + +static int l2tp_create_session_handler(sd_netlink *rtnl, sd_netlink_message *m, L2tpSession *session) { + NetDev *netdev; + int r; + + assert(session); + assert(session->tunnel); + + netdev = NETDEV(session->tunnel); + + r = sd_netlink_message_get_errno(m); + if (r == -EEXIST) + log_netdev_info(netdev, "L2TP session %s exists, using existing without changing its parameters", + session->name); + else if (r < 0) { + log_netdev_warning_errno(netdev, r, "L2TP session %s could not be created: %m", session->name); + return 1; + } + + log_netdev_debug(netdev, "L2TP session %s created", session->name); + return 1; +} + +static int l2tp_create_session(NetDev *netdev, L2tpSession *session) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *n = NULL; + int r; + + r = netdev_l2tp_fill_message_session(netdev, session, &n); + if (r < 0) + return r; + + r = netlink_call_async(netdev->manager->genl, NULL, n, l2tp_create_session_handler, + l2tp_session_destroy_callback, session); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Failed to create L2TP session %s: %m", session->name); + + netdev_ref(netdev); + return 0; +} + +static int l2tp_create_tunnel_handler(sd_netlink *rtnl, sd_netlink_message *m, NetDev *netdev) { + L2tpSession *session; + L2tpTunnel *t; + int r; + + assert(netdev); + assert(netdev->state != _NETDEV_STATE_INVALID); + + t = L2TP(netdev); + + assert(t); + + r = sd_netlink_message_get_errno(m); + if (r == -EEXIST) + log_netdev_info(netdev, "netdev exists, using existing without changing its parameters"); + else if (r < 0) { + log_netdev_warning_errno(netdev, r, "netdev could not be created: %m"); + netdev_drop(netdev); + + return 1; + } + + log_netdev_debug(netdev, "L2TP tunnel is created"); + + ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section) + (void) l2tp_create_session(netdev, session); + + return 1; +} + +static int l2tp_create_tunnel(NetDev *netdev, Link *link) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + union in_addr_union local_address; + L2tpTunnel *t; + int r; + + assert(netdev); + + t = L2TP(netdev); + + assert(t); + + r = l2tp_acquire_local_address(t, link, &local_address); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Could not find local address."); + + if (r > 0 && DEBUG_LOGGING) { + _cleanup_free_ char *str = NULL; + + (void) in_addr_to_string(t->family, &local_address, &str); + log_netdev_debug(netdev, "Local address %s acquired.", strna(str)); + } + + r = netdev_l2tp_fill_message_tunnel(netdev, &local_address, &m); + if (r < 0) + return r; + + r = netlink_call_async(netdev->manager->genl, NULL, m, l2tp_create_tunnel_handler, + netdev_destroy_callback, netdev); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Failed to create L2TP tunnel: %m"); + + netdev_ref(netdev); + + return 0; +} + +int config_parse_l2tp_tunnel_address( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + L2tpTunnel *t = userdata; + union in_addr_union *addr = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(data); + + if (streq(lvalue, "Local")) { + L2tpLocalAddressType addr_type; + + if (isempty(rvalue)) + addr_type = NETDEV_L2TP_LOCAL_ADDRESS_AUTO; + else + addr_type = l2tp_local_address_type_from_string(rvalue); + + if (addr_type >= 0) { + if (in_addr_is_null(t->family, &t->remote) != 0) + /* If Remote= is not specified yet, then also clear family. */ + t->family = AF_UNSPEC; + + t->local = IN_ADDR_NULL; + t->local_address_type = addr_type; + + return 0; + } + } + + if (t->family == AF_UNSPEC) + r = in_addr_from_string_auto(rvalue, &t->family, addr); + else + r = in_addr_from_string(t->family, rvalue, addr); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, + "Invalid L2TP Tunnel address specified in %s='%s', ignoring assignment: %m", lvalue, rvalue); + return 0; + } + + return 0; +} + +int config_parse_l2tp_tunnel_id( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + uint32_t *id = data, k; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(data); + + r = safe_atou32(rvalue, &k); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, + "Failed to parse L2TP tunnel id. Ignoring assignment: %s", rvalue); + return 0; + } + + if (k == 0) { + log_syntax(unit, LOG_WARNING, filename, line, 0, + "Invalid L2TP tunnel id. Ignoring assignment: %s", rvalue); + return 0; + } + + *id = k; + + return 0; +} + +int config_parse_l2tp_session_id( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL; + L2tpTunnel *t = userdata; + uint32_t k; + int r; + + assert(filename); + assert(section); + assert(lvalue); + assert(rvalue); + assert(data); + + r = l2tp_session_new_static(t, filename, section_line, &session); + if (r < 0) + return log_oom(); + + r = safe_atou32(rvalue, &k); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, + "Failed to parse L2TP session id. Ignoring assignment: %s", rvalue); + return 0; + } + + if (k == 0) { + log_syntax(unit, LOG_WARNING, filename, line, 0, + "Invalid L2TP session id. Ignoring assignment: %s", rvalue); + return 0; + } + + if (streq(lvalue, "SessionId")) + session->session_id = k; + else + session->peer_session_id = k; + + session = NULL; + return 0; +} + +int config_parse_l2tp_session_l2spec( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL; + L2tpTunnel *t = userdata; + L2tpL2specType spec; + int r; + + assert(filename); + assert(section); + assert(lvalue); + assert(rvalue); + assert(data); + + r = l2tp_session_new_static(t, filename, section_line, &session); + if (r < 0) + return log_oom(); + + spec = l2tp_l2spec_type_from_string(rvalue); + if (spec < 0) { + log_syntax(unit, LOG_WARNING, filename, line, 0, + "Failed to parse layer2 specific header type. Ignoring assignment: %s", rvalue); + return 0; + } + + session->l2tp_l2spec_type = spec; + + session = NULL; + return 0; +} + +int config_parse_l2tp_session_name( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + _cleanup_(l2tp_session_free_or_set_invalidp) L2tpSession *session = NULL; + L2tpTunnel *t = userdata; + int r; + + assert(filename); + assert(section); + assert(lvalue); + assert(rvalue); + assert(data); + + r = l2tp_session_new_static(t, filename, section_line, &session); + if (r < 0) + return log_oom(); + + if (!ifname_valid(rvalue)) { + log_syntax(unit, LOG_WARNING, filename, line, 0, + "Failed to parse L2TP tunnel session name. Ignoring assignment: %s", rvalue); + return 0; + } + + r = free_and_strdup(&session->name, rvalue); + if (r < 0) + return log_oom(); + + session = NULL; + return 0; +} + +static void l2tp_tunnel_init(NetDev *netdev) { + L2tpTunnel *t; + + assert(netdev); + + t = L2TP(netdev); + + assert(t); + + t->l2tp_encap_type = NETDEV_L2TP_ENCAPTYPE_UDP; + t->udp6_csum_rx = true; + t->udp6_csum_tx = true; +} + +static int l2tp_session_verify(L2tpSession *session) { + NetDev *netdev; + + assert(session); + assert(session->tunnel); + + netdev = NETDEV(session->tunnel); + + if (section_is_invalid(session->section)) + return -EINVAL; + + if (!session->name) + return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), + "%s: L2TP session without name configured. " + "Ignoring [L2TPSession] section from line %u", + session->section->filename, session->section->line); + + if (session->session_id == 0 || session->peer_session_id == 0) + return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), + "%s: L2TP session without session IDs configured. " + "Ignoring [L2TPSession] section from line %u", + session->section->filename, session->section->line); + + return 0; +} + +static int netdev_l2tp_tunnel_verify(NetDev *netdev, const char *filename) { + L2tpTunnel *t; + L2tpSession *session; + + assert(netdev); + assert(filename); + + t = L2TP(netdev); + + assert(t); + + if (!IN_SET(t->family, AF_INET, AF_INET6)) + return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), + "%s: L2TP tunnel with invalid address family configured. Ignoring", + filename); + + if (in_addr_is_null(t->family, &t->remote)) + return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), + "%s: L2TP tunnel without a remote address configured. Ignoring", + filename); + + if (t->tunnel_id == 0 || t->peer_tunnel_id == 0) + return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL), + "%s: L2TP tunnel without tunnel IDs configured. Ignoring", + filename); + + ORDERED_HASHMAP_FOREACH(session, t->sessions_by_section) + if (l2tp_session_verify(session) < 0) + l2tp_session_free(session); + + return 0; +} + +static void l2tp_tunnel_done(NetDev *netdev) { + L2tpTunnel *t; + + assert(netdev); + + t = L2TP(netdev); + + assert(t); + + ordered_hashmap_free_with_destructor(t->sessions_by_section, l2tp_session_free); +} + +const NetDevVTable l2tptnl_vtable = { + .object_size = sizeof(L2tpTunnel), + .init = l2tp_tunnel_init, + .sections = NETDEV_COMMON_SECTIONS "L2TP\0L2TPSession\0", + .create_after_configured = l2tp_create_tunnel, + .done = l2tp_tunnel_done, + .create_type = NETDEV_CREATE_AFTER_CONFIGURED, + .config_verify = netdev_l2tp_tunnel_verify, +}; |