/** * @file kernel_interface.c * * @brief Implementation of kernel_interface_t. * */ /* * Copyright (C) 2006-2007 Fabian Hartmann, Noah Heusser * Copyright (C) 2006-2007 Tobias Brunner * Copyright (C) 2006 Daniel Roethlisberger * Copyright (C) 2005-2006 Martin Willi * Copyright (C) 2005 Jan Hutter * Hochschule fuer Technik Rapperswil * Copyright (C) 2003 Herbert Xu. * * Contains modified parts from pluto. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. See . * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kernel_interface.h" #include #include #include #include #include /** kernel level protocol identifiers */ #define KERNEL_ESP 50 #define KERNEL_AH 51 /** default priority of installed policies */ #define PRIO_LOW 3000 #define PRIO_HIGH 2000 #define BUFFER_SIZE 1024 /** * returns a pointer to the first rtattr following the nlmsghdr *nlh and the * 'usual' netlink data x like 'struct xfrm_usersa_info' */ #define XFRM_RTA(nlh, x) ((struct rtattr*)(NLMSG_DATA(nlh) + NLMSG_ALIGN(sizeof(x)))) /** * returns a pointer to the next rtattr following rta. * !!! do not use this to parse messages. use RTA_NEXT and RTA_OK instead !!! */ #define XFRM_RTA_NEXT(rta) ((struct rtattr*)(((char*)(rta)) + RTA_ALIGN((rta)->rta_len))) /** * returns the total size of attached rta data * (after 'usual' netlink data x like 'struct xfrm_usersa_info') */ #define XFRM_PAYLOAD(nlh, x) NLMSG_PAYLOAD(nlh, sizeof(x)) typedef struct kernel_algorithm_t kernel_algorithm_t; /** * Mapping from the algorithms defined in IKEv2 to * kernel level algorithm names and their key length */ struct kernel_algorithm_t { /** * Identifier specified in IKEv2 */ int ikev2_id; /** * Name of the algorithm, as used as kernel identifier */ char *name; /** * Key length in bits, if fixed size */ u_int key_size; }; #define END_OF_LIST -1 /** * Algorithms for encryption */ kernel_algorithm_t encryption_algs[] = { /* {ENCR_DES_IV64, "***", 0}, */ {ENCR_DES, "des", 64}, {ENCR_3DES, "des3_ede", 192}, /* {ENCR_RC5, "***", 0}, */ /* {ENCR_IDEA, "***", 0}, */ {ENCR_CAST, "cast128", 0}, {ENCR_BLOWFISH, "blowfish", 0}, /* {ENCR_3IDEA, "***", 0}, */ /* {ENCR_DES_IV32, "***", 0}, */ {ENCR_NULL, "cipher_null", 0}, {ENCR_AES_CBC, "aes", 0}, /* {ENCR_AES_CTR, "***", 0}, */ {END_OF_LIST, NULL, 0}, }; /** * Algorithms for integrity protection */ kernel_algorithm_t integrity_algs[] = { {AUTH_HMAC_MD5_96, "md5", 128}, {AUTH_HMAC_SHA1_96, "sha1", 160}, /* {AUTH_DES_MAC, "***", 0}, */ /* {AUTH_KPDK_MD5, "***", 0}, */ /* {AUTH_AES_XCBC_96, "***", 0}, */ {END_OF_LIST, NULL, 0}, }; /** * Look up a kernel algorithm name and its key size */ char* lookup_algorithm(kernel_algorithm_t *kernel_algo, algorithm_t *ikev2_algo, u_int *key_size) { while (kernel_algo->ikev2_id != END_OF_LIST) { if (ikev2_algo->algorithm == kernel_algo->ikev2_id) { /* match, evaluate key length */ if (ikev2_algo->key_size) { /* variable length */ *key_size = ikev2_algo->key_size; } else { /* fixed length */ *key_size = kernel_algo->key_size; } return kernel_algo->name; } kernel_algo++; } return NULL; } typedef struct rt_refcount_t rt_refcount_t; struct rt_refcount_t { /** Index of the interface the route is bound to */ int if_index; /** Source ip of the route */ host_t *src_ip; /** Destination net */ chunk_t dst_net; /** Destination net prefixlen */ u_int8_t prefixlen; }; typedef struct kernel_policy_t kernel_policy_t; /** * Installed kernel policy. */ struct kernel_policy_t { /** direction of this policy: in, out, forward */ u_int8_t direction; /** reqid of the policy */ u_int32_t reqid; /** parameters of installed policy */ struct xfrm_selector sel; /** associated route installed for this policy */ rt_refcount_t *route; /** by how many CHILD_SA's this policy is used */ u_int refcount; }; typedef struct vip_refcount_t vip_refcount_t; /** * Reference counter for for virtual ips. */ struct vip_refcount_t { /** Index of the interface the ip is bound to */ u_int8_t if_index; /** The ip address */ host_t *ip; /** Number of times this ip is used */ u_int refcount; }; typedef struct private_kernel_interface_t private_kernel_interface_t; /** * Private variables and functions of kernel_interface class. */ struct private_kernel_interface_t { /** * Public part of the kernel_interface_t object. */ kernel_interface_t public; /** * List of installed policies (kernel_policy_t) */ linked_list_t *policies; /** * Mutex locks access to policies list. */ pthread_mutex_t pol_mutex; /** * Netlink communication socket for XFRM IPsec. */ int xfrm_socket; /** * Netlink communication socket for routing & addresses. */ int rt_socket; /** * Process id of kernel thread */ pid_t pid; /** * Sequence number for messages. */ u_int32_t seq; /** * List of responded messages. */ linked_list_t *responses; /** * Thread which receives xfrm messages. */ pthread_t xfrm_thread; /** * Thread which receives rt messages. */ pthread_t rt_thread; /** * Mutex locks access to replies list. */ pthread_mutex_t rep_mutex; /** * Condvar allows signaling of threads waiting for a reply. */ pthread_cond_t condvar; /** * List of reference counter objects for all virtual ips. */ linked_list_t *vips; /** * Mutex to lock access to vip list. */ pthread_mutex_t vip_mutex; }; /** * Sends a message down to the kernel and waits for its response */ static status_t send_message(private_kernel_interface_t *this, struct nlmsghdr *request, struct nlmsghdr **response, int socket) { size_t length; struct sockaddr_nl addr; request->nlmsg_seq = ++this->seq; request->nlmsg_pid = getpid(); memset(&addr, 0, sizeof(struct sockaddr_nl)); addr.nl_family = AF_NETLINK; addr.nl_pid = 0; addr.nl_groups = 0; length = sendto(socket,(void *)request, request->nlmsg_len, 0, (struct sockaddr *)&addr, sizeof(addr)); if (length < 0) { return FAILED; } else if (length != request->nlmsg_len) { DBG1(DBG_KNL, "error sending to netlink socket: %m"); return FAILED; } pthread_mutex_lock(&(this->rep_mutex)); DBG3(DBG_KNL, "waiting for netlink message with seq: %d", request->nlmsg_seq); while (TRUE) { iterator_t *iterator; struct nlmsghdr *listed_response; bool found = FALSE; /* search list, break if found */ iterator = this->responses->create_iterator(this->responses, TRUE); while (iterator->iterate(iterator, (void**)&listed_response)) { if (listed_response->nlmsg_seq == request->nlmsg_seq) { /* matches our request, this is the reply */ *response = listed_response; iterator->remove(iterator); found = TRUE; break; } } iterator->destroy(iterator); if (found) { break; } /* TODO: we should time out, if something goes wrong!??? */ pthread_cond_wait(&(this->condvar), &(this->rep_mutex)); } pthread_mutex_unlock(&(this->rep_mutex)); return SUCCESS; } static int supersocket; /** * Reads from a netlink socket and returns the message in a buffer. */ static void netlink_package_receiver(int socket, unsigned char *response, int response_size) { while (TRUE) { struct sockaddr_nl addr; socklen_t addr_length; size_t length; addr_length = sizeof(addr); length = recvfrom(socket, response, response_size, 0, (struct sockaddr*)&addr, &addr_length); if (length < 0) { if (errno == EINTR) { /* interrupted, try again */ DBG1(DBG_IKE, "wtf1"); continue; } charon->kill(charon, "receiving from netlink socket failed\n"); } if (!NLMSG_OK((struct nlmsghdr *)response, length)) { /* bad netlink message */ continue; } if (addr.nl_pid != 0) { /* not from kernel. not interested, try another one */ continue; } /* good message, handle it */ return; } } /** * Takes a Netlink package from the response buffer and writes it to this->responses. * Then it signals all waiting threads. */ static void add_to_package_list(private_kernel_interface_t *this, unsigned char *response) { struct nlmsghdr *hdr = (struct nlmsghdr*)response; /* add response to queue */ struct nlmsghdr *listed_response = malloc(hdr->nlmsg_len); memcpy(listed_response, response, hdr->nlmsg_len); pthread_mutex_lock(&(this->rep_mutex)); this->responses->insert_last(this->responses, (void*)listed_response); pthread_mutex_unlock(&(this->rep_mutex)); /* signal ALL waiting threads */ pthread_cond_broadcast(&(this->condvar)); } /** * Receives packages from this->xfrm_socket and puts them to this->package_list */ static void receive_xfrm_messages(private_kernel_interface_t *this) { while(TRUE) { unsigned char response[BUFFER_SIZE]; struct nlmsghdr *hdr; netlink_package_receiver(this->xfrm_socket, response, sizeof(response)); /* we handle ACQUIRE and EXPIRE messages directly */ hdr = (struct nlmsghdr*)response; if (hdr->nlmsg_type == XFRM_MSG_ACQUIRE) { u_int32_t reqid = 0; job_t *job; struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_user_acquire); size_t rtsize = XFRM_PAYLOAD(hdr, struct xfrm_user_tmpl); if (RTA_OK(rthdr, rtsize)) { if (rthdr->rta_type == XFRMA_TMPL) { struct xfrm_user_tmpl* tmpl = (struct xfrm_user_tmpl*)RTA_DATA(rthdr); reqid = tmpl->reqid; } } if (reqid == 0) { DBG1(DBG_KNL, "received a XFRM_MSG_ACQUIRE, but no reqid found"); } else { DBG2(DBG_KNL, "received a XFRM_MSG_ACQUIRE"); DBG1(DBG_KNL, "creating acquire job for CHILD_SA with reqid %d", reqid); job = (job_t*)acquire_job_create(reqid); charon->job_queue->add(charon->job_queue, job); } } else if (hdr->nlmsg_type == XFRM_MSG_EXPIRE) { job_t *job; protocol_id_t protocol; u_int32_t spi, reqid; struct xfrm_user_expire *expire; expire = (struct xfrm_user_expire*)NLMSG_DATA(hdr); protocol = expire->state.id.proto == KERNEL_ESP ? PROTO_ESP : PROTO_AH; spi = expire->state.id.spi; reqid = expire->state.reqid; DBG2(DBG_KNL, "received a XFRM_MSG_EXPIRE"); DBG1(DBG_KNL, "creating %s job for %N CHILD_SA 0x%x (reqid %d)", expire->hard ? "delete" : "rekey", protocol_id_names, protocol, ntohl(spi), reqid); if (expire->hard) { job = (job_t*)delete_child_sa_job_create(reqid, protocol, spi); } else { job = (job_t*)rekey_child_sa_job_create(reqid, protocol, spi); } charon->job_queue->add(charon->job_queue, job); } /* NLMSG_ERROR is sent back for acknowledge (or on error). * XFRM_MSG_NEWSA is returned when we alloc spis and when * updating SAs. * XFRM_MSG_NEWPOLICY is returned when we query a policy. */ else if (hdr->nlmsg_type == NLMSG_ERROR || hdr->nlmsg_type == XFRM_MSG_NEWSA || hdr->nlmsg_type == XFRM_MSG_NEWPOLICY) { add_to_package_list(this, response); } /* we are not interested in anything other. * anyway, move on to the next message */ continue; } } /** * Receives packages from this->rt_socket and puts them to this->package_list */ static void receive_rt_messages(private_kernel_interface_t *this) { while(TRUE) { unsigned char response[BUFFER_SIZE*3]; struct nlmsghdr *hdr; supersocket = this->rt_socket; netlink_package_receiver(this->rt_socket,response, sizeof(response)); hdr = (struct nlmsghdr*)response; /* NLMSG_ERROR is sent back for acknowledge (or on error). * RTM_NEWROUTE is returned when we add a route. */ if (hdr->nlmsg_type == NLMSG_ERROR || hdr->nlmsg_type == RTM_NEWROUTE || hdr->nlmsg_type == RTM_NEWLINK || hdr->nlmsg_type == RTM_NEWADDR) { add_to_package_list(this, response); } /* we are not interested in anything other. * anyway, move on to the next message. */ continue; } } /** * convert a host_t to a struct xfrm_address */ static void host2xfrm(host_t *host, xfrm_address_t *xfrm) { chunk_t chunk = host->get_address(host); memcpy(xfrm, chunk.ptr, min(chunk.len, sizeof(xfrm_address_t))); } /** * Implementation of kernel_interface_t.get_spi. */ static status_t get_spi(private_kernel_interface_t *this, host_t *src, host_t *dst, protocol_id_t protocol, u_int32_t reqid, u_int32_t *spi) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; struct nlmsghdr *hdr; struct xfrm_userspi_info *userspi; memset(&request, 0, sizeof(request)); status_t status = SUCCESS; DBG2(DBG_KNL, "getting spi"); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST; hdr->nlmsg_type = XFRM_MSG_ALLOCSPI; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userspi_info)); userspi = (struct xfrm_userspi_info*)NLMSG_DATA(hdr); host2xfrm(src, &userspi->info.saddr); host2xfrm(dst, &userspi->info.id.daddr); userspi->info.id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH; userspi->info.mode = TRUE; /* tunnel mode */ userspi->info.reqid = reqid; userspi->info.family = src->get_family(src); userspi->min = 0xc0000000; userspi->max = 0xcFFFFFFF; if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type == NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_ALLOCSPI got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); status = FAILED; } else if (response->nlmsg_type != XFRM_MSG_NEWSA) { DBG1(DBG_KNL, "netlink request XFRM_MSG_ALLOCSPI got a unknown reply"); status = FAILED; } else if (response->nlmsg_len < NLMSG_LENGTH(sizeof(struct xfrm_usersa_info))) { DBG1(DBG_KNL, "netlink request XFRM_MSG_ALLOCSPI got an invalid reply"); status = FAILED; } else { *spi = ((struct xfrm_usersa_info*)NLMSG_DATA(response))->id.spi; DBG2(DBG_KNL, "SPI is 0x%x", *spi); } free(response); return status; } /** * Implementation of kernel_interface_t.add_sa. */ static status_t add_sa(private_kernel_interface_t *this, host_t *src, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int32_t reqid, u_int64_t expire_soft, u_int64_t expire_hard, algorithm_t *enc_alg, algorithm_t *int_alg, prf_plus_t *prf_plus, natt_conf_t *natt, mode_t mode, bool replace) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; char *alg_name; u_int key_size; struct nlmsghdr *hdr; struct xfrm_usersa_info *sa; memset(&request, 0, sizeof(request)); status_t status = SUCCESS; DBG2(DBG_KNL, "adding SA"); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; hdr->nlmsg_type = replace ? XFRM_MSG_UPDSA : XFRM_MSG_NEWSA; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info)); sa = (struct xfrm_usersa_info*)NLMSG_DATA(hdr); host2xfrm(src, &sa->saddr); host2xfrm(dst, &sa->id.daddr); sa->id.spi = spi; sa->id.proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH; sa->family = src->get_family(src); sa->mode = mode; sa->replay_window = 32; sa->reqid = reqid; /* we currently do not expire SAs by volume/packet count */ sa->lft.soft_byte_limit = XFRM_INF; sa->lft.hard_byte_limit = XFRM_INF; sa->lft.soft_packet_limit = XFRM_INF; sa->lft.hard_packet_limit = XFRM_INF; /* we use lifetimes since added, not since used */ sa->lft.soft_add_expires_seconds = expire_soft; sa->lft.hard_add_expires_seconds = expire_hard; sa->lft.soft_use_expires_seconds = 0; sa->lft.hard_use_expires_seconds = 0; struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_usersa_info); if (enc_alg->algorithm != ENCR_UNDEFINED) { rthdr->rta_type = XFRMA_ALG_CRYPT; alg_name = lookup_algorithm(encryption_algs, enc_alg, &key_size); if (alg_name == NULL) { DBG1(DBG_KNL, "algorithm %N not supported by kernel!", encryption_algorithm_names, enc_alg->algorithm); return FAILED; } DBG2(DBG_KNL, " using encryption algorithm %N with key size %d", encryption_algorithm_names, enc_alg->algorithm, key_size); rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo) + key_size); hdr->nlmsg_len += rthdr->rta_len; if (hdr->nlmsg_len > sizeof(request)) { return FAILED; } struct xfrm_algo* algo = (struct xfrm_algo*)RTA_DATA(rthdr); algo->alg_key_len = key_size; strcpy(algo->alg_name, alg_name); prf_plus->get_bytes(prf_plus, key_size / 8, algo->alg_key); rthdr = XFRM_RTA_NEXT(rthdr); } if (int_alg->algorithm != AUTH_UNDEFINED) { rthdr->rta_type = XFRMA_ALG_AUTH; alg_name = lookup_algorithm(integrity_algs, int_alg, &key_size); if (alg_name == NULL) { DBG1(DBG_KNL, "algorithm %N not supported by kernel!", integrity_algorithm_names, int_alg->algorithm); return FAILED; } DBG2(DBG_KNL, " using integrity algorithm %N with key size %d", integrity_algorithm_names, int_alg->algorithm, key_size); rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo) + key_size); hdr->nlmsg_len += rthdr->rta_len; if (hdr->nlmsg_len > sizeof(request)) { return FAILED; } struct xfrm_algo* algo = (struct xfrm_algo*)RTA_DATA(rthdr); algo->alg_key_len = key_size; strcpy(algo->alg_name, alg_name); prf_plus->get_bytes(prf_plus, key_size / 8, algo->alg_key); rthdr = XFRM_RTA_NEXT(rthdr); } /* TODO: add IPComp here */ if (natt) { rthdr->rta_type = XFRMA_ENCAP; rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_encap_tmpl)); hdr->nlmsg_len += rthdr->rta_len; if (hdr->nlmsg_len > sizeof(request)) { return FAILED; } struct xfrm_encap_tmpl* encap = (struct xfrm_encap_tmpl*)RTA_DATA(rthdr); encap->encap_type = UDP_ENCAP_ESPINUDP; encap->encap_sport = htons(natt->sport); encap->encap_dport = htons(natt->dport); memset(&encap->encap_oa, 0, sizeof (xfrm_address_t)); /* encap_oa could probably be derived from the * traffic selectors [rfc4306, p39]. In the netlink kernel implementation * pluto does the same as we do here but it uses encap_oa in the * pfkey implementation. BUT as /usr/src/linux/net/key/af_key.c indicates * the kernel ignores it anyway * -> does that mean that NAT-T encap doesn't work in transport mode? * No. The reason the kernel ignores NAT-OA is that it recomputes * (or, rather, just ignores) the checksum. If packets pass * the IPsec checks it marks them "checksum ok" so OA isn't needed. */ rthdr = XFRM_RTA_NEXT(rthdr); } if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type != NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_NEWSA not acknowledged"); status = FAILED; } else if (((struct nlmsgerr*)NLMSG_DATA(response))->error) { DBG1(DBG_KNL, "netlink request XFRM_MSG_NEWSA got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); status = FAILED; } free(response); return status; } /** * Implementation of kernel_interface_t.update_sa. */ static status_t update_sa( private_kernel_interface_t *this, host_t *src, host_t *dst, host_t *new_src, host_t *new_dst, host_diff_t src_changes, host_diff_t dst_changes, u_int32_t spi, protocol_id_t protocol) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *update, *response; struct nlmsghdr *hdr; struct xfrm_usersa_id *sa_id; memset(&request, 0, sizeof(request)); status_t status = SUCCESS; DBG2(DBG_KNL, "getting SA"); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST; hdr->nlmsg_type = XFRM_MSG_GETSA; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_id)); sa_id = (struct xfrm_usersa_id*)NLMSG_DATA(hdr); host2xfrm(dst, &sa_id->daddr); sa_id->spi = spi; sa_id->proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH; sa_id->family = dst->get_family(dst); if (send_message(this, hdr, &update, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (update->nlmsg_type == NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETSA got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(update))->error)); free(update); return FAILED; } else if (update->nlmsg_type != XFRM_MSG_NEWSA) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETSA got a unknown reply"); free(update); return FAILED; } else if (update->nlmsg_len < NLMSG_LENGTH(sizeof(struct xfrm_usersa_info))) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETSA got an invalid reply"); free(update); return FAILED; } DBG2(DBG_KNL, "updating SA"); update->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; update->nlmsg_type = XFRM_MSG_UPDSA; struct xfrm_usersa_info *sa = (struct xfrm_usersa_info*)NLMSG_DATA(update); if (src_changes & HOST_DIFF_ADDR) { host2xfrm(new_src, &sa->saddr); } if (dst_changes & HOST_DIFF_ADDR) { DBG2(DBG_KNL, "destination address changed! replacing SA"); update->nlmsg_type = XFRM_MSG_NEWSA; host2xfrm(new_dst, &sa->id.daddr); } if (src_changes & HOST_DIFF_PORT || dst_changes & HOST_DIFF_PORT) { struct rtattr *rthdr = XFRM_RTA(update, struct xfrm_usersa_info); size_t rtsize = XFRM_PAYLOAD(update, struct xfrm_usersa_info); while (RTA_OK(rthdr, rtsize)) { if (rthdr->rta_type == XFRMA_ENCAP) { struct xfrm_encap_tmpl* encap = (struct xfrm_encap_tmpl*)RTA_DATA(rthdr); encap->encap_sport = ntohs(new_src->get_port(new_src)); encap->encap_dport = ntohs(new_dst->get_port(new_dst)); break; } rthdr = RTA_NEXT(rthdr, rtsize); } } if (send_message(this, update, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); free(update); return FAILED; } else if (response->nlmsg_type != NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_XXXSA not acknowledged"); status = FAILED; } else if (((struct nlmsgerr*)NLMSG_DATA(response))->error) { DBG1(DBG_KNL, "netlink request XFRM_MSG_XXXSA got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); status = FAILED; } else if (dst_changes & HOST_DIFF_ADDR) { DBG2(DBG_KNL, "deleting old SA"); status = this->public.del_sa(&this->public, dst, spi, protocol); } free(update); free(response); return status; } /** * Implementation of kernel_interface_t.query_sa. */ static status_t query_sa(private_kernel_interface_t *this, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int32_t *use_time) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; struct nlmsghdr *hdr; struct xfrm_usersa_id *sa_id; struct xfrm_usersa_info *sa_info; DBG2(DBG_KNL, "querying SA"); memset(&request, 0, sizeof(request)); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST; hdr->nlmsg_type = XFRM_MSG_GETSA; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info)); sa_id = (struct xfrm_usersa_id*)NLMSG_DATA(hdr); host2xfrm(dst, &sa_id->daddr); sa_id->spi = spi; sa_id->proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH; sa_id->family = dst->get_family(dst); if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type != XFRM_MSG_NEWSA) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETSA not acknowledged"); free(response); return FAILED; } else if (response->nlmsg_len < NLMSG_LENGTH(sizeof(struct xfrm_usersa_info))) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETSA got an invalid reply"); free(response); return FAILED; } sa_info = (struct xfrm_usersa_info*)NLMSG_DATA(response); *use_time = sa_info->curlft.use_time; free(response); return SUCCESS; } /** * Implementation of kernel_interface_t.del_sa. */ static status_t del_sa(private_kernel_interface_t *this, host_t *dst, u_int32_t spi, protocol_id_t protocol) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; struct nlmsghdr *hdr; struct xfrm_usersa_id *sa_id; memset(&request, 0, sizeof(request)); status_t status = SUCCESS; DBG2(DBG_KNL, "deleting SA"); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; hdr->nlmsg_type = XFRM_MSG_DELSA; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_id)); sa_id = (struct xfrm_usersa_id*)NLMSG_DATA(hdr); host2xfrm(dst, &sa_id->daddr); sa_id->spi = spi; sa_id->proto = (protocol == PROTO_ESP) ? KERNEL_ESP : KERNEL_AH; sa_id->family = dst->get_family(dst); if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type != NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_DELSA not acknowledged"); status = FAILED; } else if (((struct nlmsgerr*)NLMSG_DATA(response))->error) { DBG1(DBG_KNL, "netlink request XFRM_MSG_DELSA got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); status = FAILED; } free(response); return status; } /** * convert a traffic selector address range to subnet and its mask. */ static void ts2subnet(traffic_selector_t* ts, xfrm_address_t *net, u_int8_t *mask) { /* there is no way to do this cleanly, as the address range may * be anything else but a subnet. We use from_addr as subnet * and try to calculate a usable subnet mask. */ int byte, bit; bool found = FALSE; chunk_t from, to; size_t size = (ts->get_type(ts) == TS_IPV4_ADDR_RANGE) ? 4 : 16; from = ts->get_from_address(ts); to = ts->get_to_address(ts); *mask = (size * 8); /* go trough all bits of the addresses, beginning in the front. * as long as they are equal, the subnet gets larger */ for (byte = 0; byte < size; byte++) { for (bit = 7; bit >= 0; bit--) { if ((1<get_from_port(ts); to = ts->get_to_port(ts); if (from == to) { *port = htons(from); *mask = ~0; } else { *port = 0; *mask = 0; } } /** * convert a pair of traffic_selectors to a xfrm_selector */ static struct xfrm_selector ts2selector(traffic_selector_t *src, traffic_selector_t *dst) { struct xfrm_selector sel; memset(&sel, 0, sizeof(sel)); sel.family = src->get_type(src) == TS_IPV4_ADDR_RANGE ? AF_INET : AF_INET6; /* src or dest proto may be "any" (0), use more restrictive one */ sel.proto = max(src->get_protocol(src), dst->get_protocol(dst)); ts2subnet(dst, &sel.daddr, &sel.prefixlen_d); ts2subnet(src, &sel.saddr, &sel.prefixlen_s); ts2ports(dst, &sel.dport, &sel.dport_mask); ts2ports(src, &sel.sport, &sel.sport_mask); sel.ifindex = 0; sel.user = 0; return sel; } /** * Tries to find an ip address of a local interface that is included in the * supplied traffic selector. */ static status_t find_addr_by_ts(traffic_selector_t *ts, host_t **ip) { host_t *try = NULL, *local; int family; /* if we have a family which includes localhost, we do not * search for an IP, we use the default */ family = ts->get_type(ts) == TS_IPV4_ADDR_RANGE ? AF_INET : AF_INET6; if (family == AF_INET) { local = host_create_from_string("127.0.0.1", 0); } else { local = host_create_from_string("::1", 0); } if (ts->includes(ts, local)) { *ip = host_create_any(family); local->destroy(local); return SUCCESS; } local->destroy(local); #ifdef HAVE_GETIFADDRS struct ifaddrs *list; struct ifaddrs *cur; if (getifaddrs(&list) < 0) { return FAILED; } for (cur = list; cur != NULL; cur = cur->ifa_next) { if (!(cur->ifa_flags & IFF_UP) || !cur->ifa_addr) { /* ignore interfaces which are down or have no address assigned */ continue; } try = host_create_from_sockaddr(cur->ifa_addr); if (try && ts->includes(ts, try)) { if (ip) { *ip = try; } freeifaddrs(list); return SUCCESS; } DESTROY_IF(try); } freeifaddrs(list); return FAILED; #else /* !HAVE_GETIFADDRS */ /* only IPv4 supported yet */ if (ts->get_type(ts) != TS_IPV4_ADDR_RANGE) { return FAILED; } int skt = socket(PF_INET, SOCK_DGRAM, 0); struct ifconf conf; struct ifreq reqs[16]; conf.ifc_len = sizeof(reqs); conf.ifc_req = reqs; if (ioctl(skt, SIOCGIFCONF, &conf) == -1) { DBG1(DBG_NET, "checking address using ioctl() failed: %m"); close(skt); return FAILED; } close(skt); while (conf.ifc_len >= sizeof(struct ifreq)) { /* only IPv4 supported yet */ if (conf.ifc_req->ifr_addr.sa_family != AF_INET) { continue; } try = host_create_from_sockaddr(&conf.ifc_req->ifr_addr); if (try && ts->includes(ts, try)) { if (ip) { *ip = try; } return SUCCESS; } DESTROY_IF(try); conf.ifc_len -= sizeof(struct ifreq); conf.ifc_req++; } return FAILED; #endif /* HAVE_GETIFADDRS */ } /** * forward declarations */ static status_t manage_srcroute(private_kernel_interface_t*,int,int,rt_refcount_t*); static int get_iface(private_kernel_interface_t*,host_t*); static void rt_refcount_destroy(rt_refcount_t*); /** * Implementation of kernel_interface_t.add_policy. */ static status_t add_policy(private_kernel_interface_t *this, host_t *src, host_t *dst, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, protocol_id_t protocol, u_int32_t reqid, bool high_prio, mode_t mode, bool update) { iterator_t *iterator; kernel_policy_t *current, *policy; bool found = FALSE; unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; struct xfrm_userpolicy_info *policy_info; struct nlmsghdr *hdr; /* create a policy */ policy = malloc_thing(kernel_policy_t); memset(policy, 0, sizeof(kernel_policy_t)); policy->sel = ts2selector(src_ts, dst_ts); policy->direction = direction; /* find the policy, which matches EXACTLY */ pthread_mutex_lock(&this->pol_mutex); iterator = this->policies->create_iterator(this->policies, TRUE); while (iterator->iterate(iterator, (void**)¤t)) { if (memcmp(¤t->sel, &policy->sel, sizeof(struct xfrm_selector)) == 0 && policy->direction == current->direction) { free(policy); /* use existing policy */ if (!update) { current->refcount++; DBG2(DBG_KNL, "policy already exists, increasing refcount"); if (!high_prio) { /* if added policy is for a ROUTED child_sa, do not * overwrite existing INSTALLED policy */ iterator->destroy(iterator); pthread_mutex_unlock(&this->pol_mutex); return SUCCESS; } } policy = current; found = TRUE; break; } } iterator->destroy(iterator); if (!found) { /* apply the new one, if we have no such policy */ this->policies->insert_last(this->policies, policy); policy->refcount = 1; } DBG2(DBG_KNL, "adding policy"); memset(&request, 0, sizeof(request)); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; hdr->nlmsg_type = XFRM_MSG_UPDPOLICY; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_info)); policy_info = (struct xfrm_userpolicy_info*)NLMSG_DATA(hdr); policy_info->sel = policy->sel; policy_info->dir = policy->direction; /* calculate priority based on source selector size, small size = high prio */ policy_info->priority = high_prio ? PRIO_HIGH : PRIO_LOW; policy_info->priority -= policy->sel.prefixlen_s * 10; policy_info->priority -= policy->sel.proto ? 2 : 0; policy_info->priority -= policy->sel.sport_mask ? 1 : 0; policy_info->action = XFRM_POLICY_ALLOW; policy_info->share = XFRM_SHARE_ANY; pthread_mutex_unlock(&this->pol_mutex); /* policies don't expire */ policy_info->lft.soft_byte_limit = XFRM_INF; policy_info->lft.soft_packet_limit = XFRM_INF; policy_info->lft.hard_byte_limit = XFRM_INF; policy_info->lft.hard_packet_limit = XFRM_INF; policy_info->lft.soft_add_expires_seconds = 0; policy_info->lft.hard_add_expires_seconds = 0; policy_info->lft.soft_use_expires_seconds = 0; policy_info->lft.hard_use_expires_seconds = 0; struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_userpolicy_info); rthdr->rta_type = XFRMA_TMPL; rthdr->rta_len = sizeof(struct xfrm_user_tmpl); rthdr->rta_len = RTA_LENGTH(rthdr->rta_len); hdr->nlmsg_len += rthdr->rta_len; if (hdr->nlmsg_len > sizeof(request)) { return FAILED; } struct xfrm_user_tmpl *tmpl = (struct xfrm_user_tmpl*)RTA_DATA(rthdr); tmpl->reqid = reqid; tmpl->id.proto = (protocol == PROTO_AH) ? KERNEL_AH : KERNEL_ESP; tmpl->aalgos = tmpl->ealgos = tmpl->calgos = ~0; tmpl->mode = mode; tmpl->family = src->get_family(src); host2xfrm(src, &tmpl->saddr); host2xfrm(dst, &tmpl->id.daddr); if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type != NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_UPDPOLICY not acknowledged"); free(response); return FAILED; } else if (((struct nlmsgerr*)NLMSG_DATA(response))->error) { DBG1(DBG_KNL, "netlink request XFRM_MSG_UPDPOLICY got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); free(response); return FAILED; } if (direction == POLICY_FWD) { policy->route = malloc_thing(rt_refcount_t); if (find_addr_by_ts(dst_ts, &policy->route->src_ip) == SUCCESS) { policy->route->if_index = get_iface(this, dst); policy->route->dst_net = chunk_alloc(policy->sel.family == AF_INET ? 4 : 16); memcpy(policy->route->dst_net.ptr, &policy->sel.saddr, policy->route->dst_net.len); policy->route->prefixlen = policy->sel.prefixlen_s; if (manage_srcroute(this, RTM_NEWROUTE, NLM_F_CREATE | NLM_F_EXCL, policy->route) != SUCCESS) { DBG1(DBG_KNL, "error installing route"); rt_refcount_destroy(policy->route); policy->route = NULL; } } else { free(policy->route); policy->route = NULL; } } free(response); return SUCCESS; } /** * Implementation of kernel_interface_t.query_policy. */ static status_t query_policy(private_kernel_interface_t *this, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, u_int32_t *use_time) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; struct nlmsghdr *hdr; struct xfrm_userpolicy_id *policy_id; struct xfrm_userpolicy_info *policy; memset(&request, 0, sizeof(request)); status_t status = SUCCESS; DBG2(DBG_KNL, "querying policy"); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST; hdr->nlmsg_type = XFRM_MSG_GETPOLICY; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_id)); policy_id = (struct xfrm_userpolicy_id*)NLMSG_DATA(hdr); policy_id->sel = ts2selector(src_ts, dst_ts); policy_id->dir = direction; if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type == NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETPOLICY got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); free(response); return FAILED; } else if (response->nlmsg_type != XFRM_MSG_NEWPOLICY) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETPOLICY got an unknown reply"); free(response); return FAILED; } else if (response->nlmsg_len < NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_info))) { DBG1(DBG_KNL, "netlink request XFRM_MSG_GETPOLICY got an invalid reply"); free(response); return FAILED; } policy = (struct xfrm_userpolicy_info*)NLMSG_DATA(response); *use_time = (time_t)policy->curlft.use_time; free(response); return status; } /** * Implementation of kernel_interface_t.del_policy. */ static status_t del_policy(private_kernel_interface_t *this, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction) { kernel_policy_t *current, policy, *to_delete = NULL; rt_refcount_t *route; unsigned char request[BUFFER_SIZE]; struct nlmsghdr *response; struct nlmsghdr *hdr; struct xfrm_userpolicy_id *policy_id; iterator_t *iterator; DBG2(DBG_KNL, "deleting policy"); /* create a policy */ memset(&policy, 0, sizeof(kernel_policy_t)); policy.sel = ts2selector(src_ts, dst_ts); policy.direction = direction; /* find the policy */ pthread_mutex_lock(&this->pol_mutex); iterator = this->policies->create_iterator(this->policies, TRUE); while (iterator->iterate(iterator, (void**)¤t)) { if (memcmp(¤t->sel, &policy.sel, sizeof(struct xfrm_selector)) == 0 && policy.direction == current->direction) { to_delete = current; if (--to_delete->refcount > 0) { /* is used by more SAs, keep in kernel */ DBG2(DBG_KNL, "is used by other SAs, not removed"); iterator->destroy(iterator); pthread_mutex_unlock(&this->pol_mutex); return SUCCESS; } /* remove if last reference */ iterator->remove(iterator); break; } } iterator->destroy(iterator); pthread_mutex_unlock(&this->pol_mutex); if (!to_delete) { DBG1(DBG_KNL, "no such policy found"); return NOT_FOUND; } memset(&request, 0, sizeof(request)); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; hdr->nlmsg_type = XFRM_MSG_DELPOLICY; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_userpolicy_id)); policy_id = (struct xfrm_userpolicy_id*)NLMSG_DATA(hdr); policy_id->sel = to_delete->sel; policy_id->dir = direction; route = to_delete->route; free(to_delete); if (send_message(this, hdr, &response, this->xfrm_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (response->nlmsg_type != NLMSG_ERROR) { DBG1(DBG_KNL, "netlink request XFRM_MSG_DELPOLICY not acknowledged"); free(response); return FAILED; } else if (((struct nlmsgerr*)NLMSG_DATA(response))->error) { DBG1(DBG_KNL, "netlink request XFRM_MSG_DELPOLICY got an error: %s", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error)); free(response); return FAILED; } if (route) { if (manage_srcroute(this, RTM_DELROUTE, 0, route) != SUCCESS) { DBG1(DBG_KNL, "error uninstalling route"); } rt_refcount_destroy(route); } free(response); return SUCCESS; } /** * Sends an RT_NETLINK request to the kernel. */ static status_t send_rtrequest(private_kernel_interface_t *this, struct nlmsghdr *hdr) { struct nlmsghdr *response; if (send_message(this, hdr, &response, this->rt_socket) != SUCCESS) { DBG1(DBG_KNL, "netlink communication failed"); return FAILED; } else if (((struct nlmsgerr*)NLMSG_DATA(response))->error) { DBG1(DBG_KNL, "netlink request got an error: %s (%d)", strerror(-((struct nlmsgerr*)NLMSG_DATA(response))->error), -((struct nlmsgerr*)NLMSG_DATA(response))->error); free(response); return FAILED; } free(response); return SUCCESS; } /** * Creates an rtattr and adds it to the netlink message. */ static status_t add_rtattr(struct nlmsghdr *hdr, int max_len, int rta_type, void *data, int data_len) { struct rtattr *rta; if (NLMSG_ALIGN(hdr->nlmsg_len) + RTA_ALIGN(data_len) > max_len) { DBG1(DBG_KNL, "netlink message exceeded bound of %d", max_len); return FAILED; } rta = (struct rtattr*)(((char*)hdr) + NLMSG_ALIGN(hdr->nlmsg_len)); rta->rta_type = rta_type; rta->rta_len = RTA_LENGTH(data_len); memcpy(RTA_DATA(rta), data, data_len); hdr->nlmsg_len = NLMSG_ALIGN(hdr->nlmsg_len) + rta->rta_len; return SUCCESS; } /** * Manages the creation and deletion of ip addresses on an interface. * By setting the appropriate nlmsg_type, the ip will be set or unset. */ static status_t manage_ipaddr(private_kernel_interface_t *this, int nlmsg_type, int flags, int if_index, host_t *ip) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *hdr; struct ifaddrmsg *msg; chunk_t chunk; DBG2(DBG_KNL, "adding virtual IP %H to interface %d", ip, if_index); memset(&request, 0, sizeof(request)); chunk = ip->get_address(ip); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; hdr->nlmsg_type = nlmsg_type; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)); msg = (struct ifaddrmsg*)NLMSG_DATA(hdr); msg->ifa_family = ip->get_family(ip); msg->ifa_flags = 0; msg->ifa_prefixlen = 8 * chunk.len; msg->ifa_scope = RT_SCOPE_UNIVERSE; msg->ifa_index = if_index; if (add_rtattr(hdr, sizeof(request), IFA_LOCAL, chunk.ptr, chunk.len) != SUCCESS) { return FAILED; } return send_rtrequest(this, hdr); } /** * send a netlink message and wait for a reply */ static status_t netlink_send(int socket, struct nlmsghdr *in, struct nlmsghdr **out, size_t *out_len) { int len, addr_len; struct sockaddr_nl addr; chunk_t result = chunk_empty, tmp; struct nlmsghdr *msg, peek; static int seq = 200; static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; pthread_mutex_lock(&mutex); in->nlmsg_seq = ++seq; in->nlmsg_pid = getpid(); memset(&addr, 0, sizeof(addr)); addr.nl_family = AF_NETLINK; addr.nl_pid = 0; addr.nl_groups = 0; while (TRUE) { len = sendto(socket, in, in->nlmsg_len, 0, (struct sockaddr*)&addr, sizeof(addr)); if (len != in->nlmsg_len) { if (errno == EINTR) { /* interrupted, try again */ continue; } pthread_mutex_unlock(&mutex); DBG1(DBG_KNL, "error sending to netlink socket: %m"); return FAILED; } break; } for(;;) { tmp = chunk_alloca(2048); msg = (struct nlmsghdr*)tmp.ptr; len = recvfrom(socket, tmp.ptr, tmp.len, 0, (struct sockaddr*)&addr, &addr_len); if (len < 0) { if (errno == EINTR) { /* interrupted, try again */ continue; } DBG1(DBG_IKE, "error reading from netlink socket: %m"); pthread_mutex_unlock(&mutex); return FAILED; } if (!NLMSG_OK(msg, len)) { DBG1(DBG_IKE, "received corrupted netlink message"); pthread_mutex_unlock(&mutex); return FAILED; } if (msg->nlmsg_seq != seq) { DBG1(DBG_IKE, "received invalid netlink sequence number"); if (msg->nlmsg_seq < seq) { continue; } pthread_mutex_unlock(&mutex); return FAILED; } tmp.len = len; result = chunk_cata("cc", result, tmp); /* NLM_F_MULTI flag does not seem to be set correctly, we use sequence * numbers to detect multi header messages */ len = recvfrom(socket, &peek, sizeof(peek), MSG_PEEK | MSG_DONTWAIT, (struct sockaddr*)&addr, &addr_len); if (len == sizeof(peek) && peek.nlmsg_seq == seq) { /* seems to be multipart */ continue; } break; } *out_len = result.len; *out = (struct nlmsghdr*)clalloc(result.ptr, result.len); pthread_mutex_unlock(&mutex); return SUCCESS; } static int get_iface(private_kernel_interface_t *this, host_t* ip) { unsigned char request[BUFFER_SIZE]; struct nlmsghdr *hdr, *tofree; struct rtgenmsg *msg; int ifindex = 0; size_t len; chunk_t target, current; memset(&request, 0, sizeof(request)); hdr = (struct nlmsghdr*)request; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)); hdr->nlmsg_type = RTM_GETADDR; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_MATCH | NLM_F_ROOT; msg = (struct rtgenmsg*)NLMSG_DATA(hdr); msg->rtgen_family = AF_UNSPEC; target = ip->get_address(ip); if (netlink_send(this->rt_socket, hdr, &hdr, &len) == SUCCESS) { tofree = hdr; while (NLMSG_OK(hdr, len)) { switch (hdr->nlmsg_type) { case RTM_NEWADDR: { struct ifaddrmsg* msg = (struct ifaddrmsg*)(NLMSG_DATA(hdr)); struct rtattr *rta = IFA_RTA(msg); size_t rtasize = IFA_PAYLOAD (hdr); while(RTA_OK(rta, rtasize)) { if (rta->rta_type == IFA_ADDRESS) { current.len = rta->rta_len - 4; current.ptr = RTA_DATA(rta); if (chunk_equals(current, target)) { ifindex = msg->ifa_index; break; } } rta = RTA_NEXT(rta, rtasize); } hdr = NLMSG_NEXT(hdr, len); continue; } default: hdr = NLMSG_NEXT(hdr, len); continue; case NLMSG_DONE: break; } break; } free(tofree); } else { DBG1(DBG_IKE, "unable to get interface address for %H", ip); } return ifindex; } /** * Manages source routes in the routing table. * By setting the appropriate nlmsg_type, the route will be set or unset. */ static status_t manage_srcroute(private_kernel_interface_t *this, int nlmsg_type, int flags, rt_refcount_t *route) { struct nlmsghdr *hdr; struct rtmsg *msg; unsigned char request[BUFFER_SIZE]; chunk_t src; /* if route is 0.0.0.0/0, we can't install it, as it would * overwrite the default route. Instead, we add two routes: * 0.0.0.0/1 and 128.0.0.0/1 */ if (route->prefixlen == 0) { rt_refcount_t half; status_t status; half.dst_net = chunk_alloca(route->dst_net.len); memset(half.dst_net.ptr, 0, half.dst_net.len); half.src_ip = route->src_ip; half.if_index = route->if_index; half.prefixlen = 1; status = manage_srcroute(this, nlmsg_type, flags, &half); half.dst_net.ptr[0] |= 0x80; status = manage_srcroute(this, nlmsg_type, flags, &half); return status; } memset(&request, 0, sizeof(request)); hdr = (struct nlmsghdr*)request; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; hdr->nlmsg_type = nlmsg_type; hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); msg = (struct rtmsg*)NLMSG_DATA(hdr); msg->rtm_family = route->src_ip->get_family(route->src_ip); msg->rtm_dst_len = route->prefixlen; msg->rtm_table = RT_TABLE_MAIN; msg->rtm_protocol = RTPROT_STATIC; msg->rtm_type = RTN_UNICAST; msg->rtm_scope = RT_SCOPE_UNIVERSE; if (add_rtattr(hdr, sizeof(request), RTA_DST, route->dst_net.ptr, route->dst_net.len) != SUCCESS) { return FAILED; } src = route->src_ip->get_address(route->src_ip); if (add_rtattr(hdr, sizeof(request), RTA_PREFSRC, src.ptr, src.len) != SUCCESS) { return FAILED; } if (add_rtattr(hdr, sizeof(request), RTA_OIF, &route->if_index, sizeof(route->if_index)) != SUCCESS) { return FAILED; } return send_rtrequest(this, hdr); } /** * destroy an rt_refcount object */ static void rt_refcount_destroy(rt_refcount_t *this) { this->src_ip->destroy(this->src_ip); chunk_free(&this->dst_net); free(this); } /** * destroy a vip_refcount object */ static void vip_refcount_destroy(vip_refcount_t *this) { this->ip->destroy(this->ip); free(this); } /** * Implementation of kernel_interface_t.add_ip. */ static status_t add_ip(private_kernel_interface_t *this, host_t *virtual_ip, host_t *iface_ip) { int targetif; vip_refcount_t *listed; iterator_t *iterator; DBG2(DBG_KNL, "adding ip addr: %H", virtual_ip); targetif = get_iface(this, iface_ip); if (targetif == 0) { return FAILED; } /* beware of deadlocks (e.g. send/receive packets while holding the lock) */ iterator = this->vips->create_iterator_locked(this->vips, &(this->vip_mutex)); while (iterator->iterate(iterator, (void**)&listed)) { if (listed->if_index == targetif && virtual_ip->ip_equals(virtual_ip, listed->ip)) { listed->refcount++; iterator->destroy(iterator); return SUCCESS; } } iterator->destroy(iterator); if (manage_ipaddr(this, RTM_NEWADDR, NLM_F_CREATE | NLM_F_EXCL, targetif, virtual_ip) == SUCCESS) { listed = malloc_thing(vip_refcount_t); listed->ip = virtual_ip->clone(virtual_ip); listed->if_index = targetif; listed->refcount = 1; this->vips->insert_last(this->vips, listed); return SUCCESS; } return FAILED; } /** * Implementation of kernel_interface_t.del_ip. */ static status_t del_ip(private_kernel_interface_t *this, host_t *virtual_ip, host_t *iface_ip) { int targetif; vip_refcount_t *listed; iterator_t *iterator; DBG2(DBG_KNL, "deleting ip addr: %H", virtual_ip); targetif = get_iface(this, iface_ip); if (targetif == 0) { return FAILED; } /* beware of deadlocks (e.g. send/receive packets while holding the lock) */ iterator = this->vips->create_iterator_locked(this->vips, &(this->vip_mutex)); while (iterator->iterate(iterator, (void**)&listed)) { if (listed->if_index == targetif && virtual_ip->ip_equals(virtual_ip, listed->ip)) { listed->refcount--; if (listed->refcount == 0) { iterator->remove(iterator); vip_refcount_destroy(listed); iterator->destroy(iterator); return manage_ipaddr(this, RTM_DELADDR, 0, targetif, virtual_ip); } iterator->destroy(iterator); return SUCCESS; } } iterator->destroy(iterator); return FAILED; } /** * Implementation of kernel_interface_t.destroy. */ static void destroy(private_kernel_interface_t *this) { pthread_cancel(this->xfrm_thread); pthread_join(this->xfrm_thread, NULL); pthread_cancel(this->rt_thread); pthread_join(this->rt_thread, NULL); close(this->xfrm_socket); close(this->rt_socket); this->vips->destroy_function(this->vips, (void*)vip_refcount_destroy); this->responses->destroy(this->responses); this->policies->destroy(this->policies); free(this); } /* * Described in header. */ kernel_interface_t *kernel_interface_create() { struct sockaddr_nl addr_xfrm; struct sockaddr_nl addr_rt; private_kernel_interface_t *this = malloc_thing(private_kernel_interface_t); /* public functions */ this->public.get_spi = (status_t(*)(kernel_interface_t*,host_t*,host_t*,protocol_id_t,u_int32_t,u_int32_t*))get_spi; this->public.add_sa = (status_t(*)(kernel_interface_t *,host_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t,u_int64_t,u_int64_t,algorithm_t*,algorithm_t*,prf_plus_t*,natt_conf_t*,mode_t,bool))add_sa; this->public.update_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t,host_t*,host_t*,host_diff_t,host_diff_t))update_sa; this->public.query_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t*))query_sa; this->public.del_sa = (status_t(*)(kernel_interface_t*,host_t*,u_int32_t,protocol_id_t))del_sa; this->public.add_policy = (status_t(*)(kernel_interface_t*,host_t*,host_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,protocol_id_t,u_int32_t,bool,mode_t,bool))add_policy; this->public.query_policy = (status_t(*)(kernel_interface_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,u_int32_t*))query_policy; this->public.del_policy = (status_t(*)(kernel_interface_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t))del_policy; this->public.add_ip = (status_t(*)(kernel_interface_t*,host_t*,host_t*)) add_ip; this->public.del_ip = (status_t(*)(kernel_interface_t*,host_t*,host_t*)) del_ip; this->public.destroy = (void(*)(kernel_interface_t*)) destroy; /* private members */ this->pid = getpid(); this->responses = linked_list_create(); this->vips = linked_list_create(); this->policies = linked_list_create(); pthread_mutex_init(&(this->rep_mutex),NULL); pthread_mutex_init(&(this->pol_mutex),NULL); pthread_mutex_init(&(this->vip_mutex),NULL); pthread_cond_init(&(this->condvar),NULL); this->seq = 0; /* open xfrm netlink socket */ this->xfrm_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_XFRM); if (this->xfrm_socket <= 0) { DBG1(DBG_KNL, "Unable to create xfrm netlink socket"); goto kill; } /* bind the xfrm socket and reqister for ACQUIRE & EXPIRE */ addr_xfrm.nl_family = AF_NETLINK; addr_xfrm.nl_pid = 0; addr_xfrm.nl_groups = XFRMGRP_ACQUIRE | XFRMGRP_EXPIRE; if (bind(this->xfrm_socket, (struct sockaddr*)&addr_xfrm, sizeof(addr_xfrm))) { DBG1(DBG_KNL, "Unable to bind xfrm netlink socket"); goto kill_xfrm; } if (pthread_create(&this->xfrm_thread, NULL, (void*(*)(void*))receive_xfrm_messages, this)) { DBG1(DBG_KNL, "Unable to create xfrm netlink thread"); goto kill_xfrm; } /* open rt netlink socket */ this->rt_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (this->rt_socket <= 0) { DBG1(DBG_KNL, "Unable to create rt netlink socket"); goto kill_xfrm_all; } /* bind the socket_rt */ addr_rt.nl_family = AF_NETLINK; addr_rt.nl_pid = 0; addr_rt.nl_groups = 0; if (bind(this->rt_socket, (struct sockaddr*)&addr_rt, sizeof(addr_rt))) { DBG1(DBG_KNL, "Unable to bind rt netlink socket"); goto kill_rt; } if (pthread_create(&this->rt_thread, NULL, (void*(*)(void*))receive_rt_messages, this)) { DBG1(DBG_KNL, "Unable to create rt netlink thread"); goto kill_rt; } return &this->public; kill_rt: close(this->rt_socket); kill_xfrm_all: pthread_cancel(this->xfrm_thread); pthread_join(this->xfrm_thread, NULL); kill_xfrm: close(this->xfrm_socket); kill: this->responses->destroy(this->responses); this->policies->destroy(this->policies); this->vips->destroy(this->vips); free(this); charon->kill(charon, "Unable to create kernel_interface"); return NULL; } /* vim: set ts=4 sw=4 noet: */