Merge branch 'radius-ext'
[strongswan.git] / src / libhydra / plugins / kernel_netlink / kernel_netlink_ipsec.c
index 8e90e01..9b4ade5 100644 (file)
 #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')
  */
@@ -176,8 +170,6 @@ ENUM(xfrm_attr_type_names, XFRMA_UNSPEC, XFRMA_REPLAY_ESN_VAL,
        "XFRMA_REPLAY_ESN_VAL",
 );
 
-#define END_OF_LIST -1
-
 /**
  * Algorithms for encryption
  */
@@ -208,7 +200,6 @@ static kernel_algorithm_t encryption_algs[] = {
 /*     {ENCR_CAMELLIA_CCM_ICV16,       "***"                           }, */
        {ENCR_SERPENT_CBC,                      "serpent"                       },
        {ENCR_TWOFISH_CBC,                      "twofish"                       },
-       {END_OF_LIST,                           NULL                            }
 };
 
 /**
@@ -226,7 +217,6 @@ static kernel_algorithm_t integrity_algs[] = {
 /*     {AUTH_DES_MAC,                          "***"                           }, */
 /*     {AUTH_KPDK_MD5,                         "***"                           }, */
        {AUTH_AES_XCBC_96,                      "xcbc(aes)"                     },
-       {END_OF_LIST,                           NULL                            }
 };
 
 /**
@@ -237,7 +227,6 @@ static kernel_algorithm_t compression_algs[] = {
        {IPCOMP_DEFLATE,                        "deflate"                       },
        {IPCOMP_LZS,                            "lzs"                           },
        {IPCOMP_LZJH,                           "lzjh"                          },
-       {END_OF_LIST,                           NULL                            }
 };
 
 /**
@@ -246,33 +235,39 @@ static kernel_algorithm_t compression_algs[] = {
 static char* lookup_algorithm(transform_type_t type, int ikev2)
 {
        kernel_algorithm_t *list;
-       char *name = NULL;
+       int i, count;
+       char *name;
 
        switch (type)
        {
                case ENCRYPTION_ALGORITHM:
                        list = encryption_algs;
+                       count = countof(encryption_algs);
                        break;
                case INTEGRITY_ALGORITHM:
                        list = integrity_algs;
+                       count = countof(integrity_algs);
                        break;
                case COMPRESSION_ALGORITHM:
                        list = compression_algs;
+                       count = countof(compression_algs);
                        break;
                default:
                        return NULL;
        }
-       while (list->ikev2 != END_OF_LIST)
+       for (i = 0; i < count; i++)
        {
-               if (list->ikev2 == ikev2)
+               if (list[i].ikev2 == ikev2)
                {
-                       return list->name;
+                       return list[i].name;
                }
-               list++;
        }
-       hydra->kernel_interface->lookup_algorithm(hydra->kernel_interface, ikev2,
-                                                                                         type, NULL, &name);
-       return name;
+       if (hydra->kernel_interface->lookup_algorithm(hydra->kernel_interface,
+                                                                                                 ikev2, type, NULL, &name))
+       {
+               return name;
+       }
+       return NULL;
 }
 
 typedef struct private_kernel_netlink_ipsec_t private_kernel_netlink_ipsec_t;
@@ -1150,6 +1145,26 @@ METHOD(kernel_ipsec_t, get_cpi, status_t,
        return SUCCESS;
 }
 
+/**
+ * Add a XFRM mark to message if required
+ */
+static bool add_mark(struct nlmsghdr *hdr, int buflen, mark_t mark)
+{
+       if (mark.value)
+       {
+               struct xfrm_mark *xmrk;
+
+               xmrk = netlink_reserve(hdr, buflen, XFRMA_MARK, sizeof(*xmrk));
+               if (!xmrk)
+               {
+                       return FALSE;
+               }
+               xmrk->v = mark.value;
+               xmrk->m = mark.mask;
+       }
+       return TRUE;
+}
+
 METHOD(kernel_ipsec_t, add_sa, status_t,
        private_kernel_netlink_ipsec_t *this, host_t *src, host_t *dst,
        u_int32_t spi, u_int8_t protocol, u_int32_t reqid, mark_t mark,
@@ -1222,8 +1237,6 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
        sa->lft.soft_use_expires_seconds = 0;
        sa->lft.hard_use_expires_seconds = 0;
 
-       struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_usersa_info);
-
        switch (enc_alg)
        {
                case ENCR_UNDEFINED:
@@ -1256,23 +1269,17 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                        DBG2(DBG_KNL, "  using encryption algorithm %N with key size %d",
                                 encryption_algorithm_names, enc_alg, enc_key.len * 8);
 
-                       rthdr->rta_type = XFRMA_ALG_AEAD;
-                       rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo_aead) +
-                                                                               enc_key.len);
-                       hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-                       if (hdr->nlmsg_len > sizeof(request))
+                       algo = netlink_reserve(hdr, sizeof(request), XFRMA_ALG_AEAD,
+                                                                  sizeof(*algo) + enc_key.len);
+                       if (!algo)
                        {
                                goto failed;
                        }
-
-                       algo = (struct xfrm_algo_aead*)RTA_DATA(rthdr);
                        algo->alg_key_len = enc_key.len * 8;
                        algo->alg_icv_len = icv_size;
                        strncpy(algo->alg_name, alg_name, sizeof(algo->alg_name));
                        algo->alg_name[sizeof(algo->alg_name) - 1] = '\0';
                        memcpy(algo->alg_key, enc_key.ptr, enc_key.len);
-
-                       rthdr = XFRM_RTA_NEXT(rthdr);
                        break;
                }
                default:
@@ -1289,21 +1296,16 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                        DBG2(DBG_KNL, "  using encryption algorithm %N with key size %d",
                                 encryption_algorithm_names, enc_alg, enc_key.len * 8);
 
-                       rthdr->rta_type = XFRMA_ALG_CRYPT;
-                       rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo) + enc_key.len);
-                       hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-                       if (hdr->nlmsg_len > sizeof(request))
+                       algo = netlink_reserve(hdr, sizeof(request), XFRMA_ALG_CRYPT,
+                                                                  sizeof(*algo) + enc_key.len);
+                       if (!algo)
                        {
                                goto failed;
                        }
-
-                       algo = (struct xfrm_algo*)RTA_DATA(rthdr);
                        algo->alg_key_len = enc_key.len * 8;
                        strncpy(algo->alg_name, alg_name, sizeof(algo->alg_name));
                        algo->alg_name[sizeof(algo->alg_name) - 1] = '\0';
                        memcpy(algo->alg_key, enc_key.ptr, enc_key.len);
-
-                       rthdr = XFRM_RTA_NEXT(rthdr);
                }
        }
 
@@ -1341,17 +1343,12 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                        /* the kernel uses SHA256 with 96 bit truncation by default,
                         * use specified truncation size supported by newer kernels.
                         * also use this for untruncated MD5 and SHA1. */
-                       rthdr->rta_type = XFRMA_ALG_AUTH_TRUNC;
-                       rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo_auth) +
-                                                                               int_key.len);
-
-                       hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-                       if (hdr->nlmsg_len > sizeof(request))
+                       algo = netlink_reserve(hdr, sizeof(request), XFRMA_ALG_AUTH_TRUNC,
+                                                                  sizeof(*algo) + int_key.len);
+                       if (!algo)
                        {
                                goto failed;
                        }
-
-                       algo = (struct xfrm_algo_auth*)RTA_DATA(rthdr);
                        algo->alg_key_len = int_key.len * 8;
                        algo->alg_trunc_len = trunc_len;
                        strncpy(algo->alg_name, alg_name, sizeof(algo->alg_name));
@@ -1362,27 +1359,23 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                {
                        struct xfrm_algo* algo;
 
-                       rthdr->rta_type = XFRMA_ALG_AUTH;
-                       rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo) + int_key.len);
-
-                       hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-                       if (hdr->nlmsg_len > sizeof(request))
+                       algo = netlink_reserve(hdr, sizeof(request), XFRMA_ALG_AUTH,
+                                                                  sizeof(*algo) + int_key.len);
+                       if (!algo)
                        {
                                goto failed;
                        }
-
-                       algo = (struct xfrm_algo*)RTA_DATA(rthdr);
                        algo->alg_key_len = int_key.len * 8;
                        strncpy(algo->alg_name, alg_name, sizeof(algo->alg_name));
                        algo->alg_name[sizeof(algo->alg_name) - 1] = '\0';
                        memcpy(algo->alg_key, int_key.ptr, int_key.len);
                }
-               rthdr = XFRM_RTA_NEXT(rthdr);
        }
 
        if (ipcomp != IPCOMP_NONE)
        {
-               rthdr->rta_type = XFRMA_ALG_COMP;
+               struct xfrm_algo* algo;
+
                alg_name = lookup_algorithm(COMPRESSION_ALGORITHM, ipcomp);
                if (alg_name == NULL)
                {
@@ -1393,35 +1386,26 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                DBG2(DBG_KNL, "  using compression algorithm %N",
                         ipcomp_transform_names, ipcomp);
 
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_algo));
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
+               algo = netlink_reserve(hdr, sizeof(request), XFRMA_ALG_COMP,
+                                                          sizeof(*algo));
+               if (!algo)
                {
                        goto failed;
                }
-
-               struct xfrm_algo* algo = (struct xfrm_algo*)RTA_DATA(rthdr);
                algo->alg_key_len = 0;
                strncpy(algo->alg_name, alg_name, sizeof(algo->alg_name));
                algo->alg_name[sizeof(algo->alg_name) - 1] = '\0';
-
-               rthdr = XFRM_RTA_NEXT(rthdr);
        }
 
        if (encap)
        {
                struct xfrm_encap_tmpl *tmpl;
 
-               rthdr->rta_type = XFRMA_ENCAP;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_encap_tmpl));
-
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
+               tmpl = netlink_reserve(hdr, sizeof(request), XFRMA_ENCAP, sizeof(*tmpl));
+               if (!tmpl)
                {
                        goto failed;
                }
-
-               tmpl = (struct xfrm_encap_tmpl*)RTA_DATA(rthdr);
                tmpl->encap_type = UDP_ENCAP_ESPINUDP;
                tmpl->encap_sport = htons(src->get_port(src));
                tmpl->encap_dport = htons(dst->get_port(dst));
@@ -1436,44 +1420,24 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                 * 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 (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       goto failed;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
-               rthdr = XFRM_RTA_NEXT(rthdr);
+               goto failed;
        }
 
        if (tfc)
        {
                u_int32_t *tfcpad;
 
-               rthdr->rta_type = XFRMA_TFCPAD;
-               rthdr->rta_len = RTA_LENGTH(sizeof(u_int32_t));
-
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
+               tfcpad = netlink_reserve(hdr, sizeof(request), XFRMA_TFCPAD,
+                                                                sizeof(*tfcpad));
+               if (!tfcpad)
                {
                        goto failed;
                }
-
-               tfcpad = (u_int32_t*)RTA_DATA(rthdr);
                *tfcpad = tfc;
-               rthdr = XFRM_RTA_NEXT(rthdr);
        }
 
        if (protocol != IPPROTO_COMP)
@@ -1484,24 +1448,18 @@ METHOD(kernel_ipsec_t, add_sa, status_t,
                         * XFRMA_REPLAY_ESN_VAL attribute to configure a bitmap */
                        struct xfrm_replay_state_esn *replay;
 
-                       rthdr->rta_type = XFRMA_REPLAY_ESN_VAL;
-                       rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_replay_state_esn) +
-                                                                               (this->replay_window + 7) / 8);
-
-                       hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-                       if (hdr->nlmsg_len > sizeof(request))
+                       replay = netlink_reserve(hdr, sizeof(request), XFRMA_REPLAY_ESN_VAL,
+                                                       sizeof(*replay) + (this->replay_window + 7) / 8);
+                       if (!replay)
                        {
                                goto failed;
                        }
-
-                       replay = (struct xfrm_replay_state_esn*)RTA_DATA(rthdr);
                        /* bmp_len contains number uf __u32's */
                        replay->bmp_len = this->replay_bmp;
                        replay->replay_window = this->replay_window;
                        DBG2(DBG_KNL, "  using replay window of %u packets",
                                 this->replay_window);
 
-                       rthdr = XFRM_RTA_NEXT(rthdr);
                        if (esn)
                        {
                                DBG2(DBG_KNL, "  using extended sequence numbers (ESN)");
@@ -1573,22 +1531,9 @@ static void get_replay_state(private_kernel_netlink_ipsec_t *this,
        aevent_id->sa_id.proto = protocol;
        aevent_id->sa_id.family = dst->get_family(dst);
 
-       if (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-               struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_aevent_id);
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       return;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
+               return;
        }
 
        if (this->socket_xfrm->send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
@@ -1675,22 +1620,9 @@ METHOD(kernel_ipsec_t, query_sa, status_t,
        sa_id->proto = protocol;
        sa_id->family = dst->get_family(dst);
 
-       if (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-               struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_usersa_id);
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       return FAILED;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
+               return FAILED;
        }
 
        if (this->socket_xfrm->send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
@@ -1785,22 +1717,9 @@ METHOD(kernel_ipsec_t, del_sa, status_t,
        sa_id->proto = protocol;
        sa_id->family = dst->get_family(dst);
 
-       if (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-               struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_usersa_id);
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       return FAILED;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
+               return FAILED;
        }
 
        switch (this->socket_xfrm->send_ack(this->socket_xfrm, hdr))
@@ -1832,7 +1751,6 @@ METHOD(kernel_ipsec_t, update_sa, status_t,
        bool old_encap, bool new_encap, mark_t mark)
 {
        netlink_buf_t request;
-       u_char *pos;
        struct nlmsghdr *hdr, *out = NULL;
        struct xfrm_usersa_id *sa_id;
        struct xfrm_usersa_info *out_sa = NULL, *sa;
@@ -1867,22 +1785,9 @@ METHOD(kernel_ipsec_t, update_sa, status_t,
        sa_id->proto = protocol;
        sa_id->family = dst->get_family(dst);
 
-       if (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-               struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_usersa_id);
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       return FAILED;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
+               return FAILED;
        }
 
        if (this->socket_xfrm->send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
@@ -1933,11 +1838,11 @@ METHOD(kernel_ipsec_t, update_sa, status_t,
                                   ntohl(spi), src, dst, new_src, new_dst);
        /* copy over the SA from out to request */
        hdr = (struct nlmsghdr*)request;
-       memcpy(hdr, out, min(out->nlmsg_len, sizeof(request)));
        hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
        hdr->nlmsg_type = XFRM_MSG_NEWSA;
        hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_info));
        sa = NLMSG_DATA(hdr);
+       memcpy(sa, NLMSG_DATA(out), sizeof(struct xfrm_usersa_info));
        sa->family = new_dst->get_family(new_dst);
 
        if (!src->ip_equals(src, new_src))
@@ -1951,75 +1856,60 @@ METHOD(kernel_ipsec_t, update_sa, status_t,
 
        rta = XFRM_RTA(out, struct xfrm_usersa_info);
        rtasize = XFRM_PAYLOAD(out, struct xfrm_usersa_info);
-       pos = (u_char*)XFRM_RTA(hdr, struct xfrm_usersa_info);
-       while(RTA_OK(rta, rtasize))
+       while (RTA_OK(rta, rtasize))
        {
                /* copy all attributes, but not XFRMA_ENCAP if we are disabling it */
                if (rta->rta_type != XFRMA_ENCAP || new_encap)
                {
                        if (rta->rta_type == XFRMA_ENCAP)
                        {       /* update encap tmpl */
-                               tmpl = (struct xfrm_encap_tmpl*)RTA_DATA(rta);
+                               tmpl = RTA_DATA(rta);
                                tmpl->encap_sport = ntohs(new_src->get_port(new_src));
                                tmpl->encap_dport = ntohs(new_dst->get_port(new_dst));
                        }
-                       memcpy(pos, rta, rta->rta_len);
-                       pos += RTA_ALIGN(rta->rta_len);
-                       hdr->nlmsg_len += RTA_ALIGN(rta->rta_len);
+                       netlink_add_attribute(hdr, rta->rta_type,
+                                                                 chunk_create(RTA_DATA(rta), RTA_PAYLOAD(rta)),
+                                                                 sizeof(request));
                }
                rta = RTA_NEXT(rta, rtasize);
        }
 
-       rta = (struct rtattr*)pos;
        if (tmpl == NULL && new_encap)
        {       /* add tmpl if we are enabling it */
-               rta->rta_type = XFRMA_ENCAP;
-               rta->rta_len = RTA_LENGTH(sizeof(struct xfrm_encap_tmpl));
-
-               hdr->nlmsg_len += RTA_ALIGN(rta->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
+               tmpl = netlink_reserve(hdr, sizeof(request), XFRMA_ENCAP, sizeof(*tmpl));
+               if (!tmpl)
                {
                        goto failed;
                }
-
-               tmpl = (struct xfrm_encap_tmpl*)RTA_DATA(rta);
                tmpl->encap_type = UDP_ENCAP_ESPINUDP;
                tmpl->encap_sport = ntohs(new_src->get_port(new_src));
                tmpl->encap_dport = ntohs(new_dst->get_port(new_dst));
                memset(&tmpl->encap_oa, 0, sizeof (xfrm_address_t));
-
-               rta = XFRM_RTA_NEXT(rta);
        }
 
        if (replay_esn)
        {
-               rta->rta_type = XFRMA_REPLAY_ESN_VAL;
-               rta->rta_len = RTA_LENGTH(sizeof(struct xfrm_replay_state_esn) +
-                                                                 this->replay_bmp);
+               struct xfrm_replay_state_esn *state;
 
-               hdr->nlmsg_len += RTA_ALIGN(rta->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
+               state = netlink_reserve(hdr, sizeof(request), XFRMA_REPLAY_ESN_VAL,
+                                                               sizeof(*state) + this->replay_bmp);
+               if (!state)
                {
                        goto failed;
                }
-               memcpy(RTA_DATA(rta), replay_esn,
-                          sizeof(struct xfrm_replay_state_esn) + this->replay_bmp);
-
-               rta = XFRM_RTA_NEXT(rta);
+               memcpy(state, replay_esn, sizeof(*state) + this->replay_bmp);
        }
        else if (replay)
        {
-               rta->rta_type = XFRMA_REPLAY_VAL;
-               rta->rta_len = RTA_LENGTH(sizeof(struct xfrm_replay_state));
+               struct xfrm_replay_state *state;
 
-               hdr->nlmsg_len += RTA_ALIGN(rta->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
+               state = netlink_reserve(hdr, sizeof(request), XFRMA_REPLAY_VAL,
+                                                               sizeof(*state));
+               if (!state)
                {
                        goto failed;
                }
-               memcpy(RTA_DATA(rta), replay, sizeof(struct xfrm_replay_state));
-
-               rta = XFRM_RTA_NEXT(rta);
+               memcpy(state, replay, sizeof(*state));
        }
        else
        {
@@ -2116,11 +2006,9 @@ static status_t add_policy_internal(private_kernel_netlink_ipsec_t *this,
        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);
-
        if (mapping->type == POLICY_IPSEC)
        {
-               struct xfrm_user_tmpl *tmpl = (struct xfrm_user_tmpl*)RTA_DATA(rthdr);
+               struct xfrm_user_tmpl *tmpl;
                struct {
                        u_int8_t proto;
                        bool use;
@@ -2130,25 +2018,29 @@ static status_t add_policy_internal(private_kernel_netlink_ipsec_t *this,
                        { IPPROTO_AH, ipsec->cfg.ah.use },
                };
                ipsec_mode_t proto_mode = ipsec->cfg.mode;
-
-               rthdr->rta_type = XFRMA_TMPL;
-               rthdr->rta_len = 0; /* actual length is set below */
+               int count = 0;
 
                for (i = 0; i < countof(protos); i++)
                {
-                       if (!protos[i].use)
+                       if (protos[i].use)
                        {
-                               continue;
+                               count++;
                        }
+               }
+               tmpl = netlink_reserve(hdr, sizeof(request), XFRMA_TMPL,
+                                                          count * sizeof(*tmpl));
+               if (!tmpl)
+               {
+                       this->mutex->unlock(this->mutex);
+                       return FAILED;
+               }
 
-                       rthdr->rta_len += RTA_LENGTH(sizeof(struct xfrm_user_tmpl));
-                       hdr->nlmsg_len += RTA_ALIGN(RTA_LENGTH(sizeof(struct xfrm_user_tmpl)));
-                       if (hdr->nlmsg_len > sizeof(request))
+               for (i = 0; i < countof(protos); i++)
+               {
+                       if (!protos[i].use)
                        {
-                               this->mutex->unlock(this->mutex);
-                               return FAILED;
+                               continue;
                        }
-
                        tmpl->reqid = ipsec->cfg.reqid;
                        tmpl->id.proto = protos[i].proto;
                        tmpl->aalgos = tmpl->ealgos = tmpl->calgos = ~0;
@@ -2168,27 +2060,12 @@ static status_t add_policy_internal(private_kernel_netlink_ipsec_t *this,
                        /* use transport mode for other SAs */
                        proto_mode = MODE_TRANSPORT;
                }
-
-               rthdr = XFRM_RTA_NEXT(rthdr);
        }
 
-       if (ipsec->mark.value)
+       if (!add_mark(hdr, sizeof(request), ipsec->mark))
        {
-               struct xfrm_mark *mrk;
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       this->mutex->unlock(this->mutex);
-                       return FAILED;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = ipsec->mark.value;
-               mrk->m = ipsec->mark.mask;
+               this->mutex->unlock(this->mutex);
+               return FAILED;
        }
        this->mutex->unlock(this->mutex);
 
@@ -2415,23 +2292,9 @@ METHOD(kernel_ipsec_t, query_policy, status_t,
        policy_id->sel = ts2selector(src_ts, dst_ts);
        policy_id->dir = direction;
 
-       if (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-               struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_userpolicy_id);
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       return FAILED;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
+               return FAILED;
        }
 
        if (this->socket_xfrm->send(this->socket_xfrm, hdr, &out, &len) == SUCCESS)
@@ -2587,23 +2450,9 @@ METHOD(kernel_ipsec_t, del_policy, status_t,
        policy_id->sel = current->sel;
        policy_id->dir = direction;
 
-       if (mark.value)
+       if (!add_mark(hdr, sizeof(request), mark))
        {
-               struct xfrm_mark *mrk;
-               struct rtattr *rthdr = XFRM_RTA(hdr, struct xfrm_userpolicy_id);
-
-               rthdr->rta_type = XFRMA_MARK;
-               rthdr->rta_len = RTA_LENGTH(sizeof(struct xfrm_mark));
-               hdr->nlmsg_len += RTA_ALIGN(rthdr->rta_len);
-               if (hdr->nlmsg_len > sizeof(request))
-               {
-                       this->mutex->unlock(this->mutex);
-                       return FAILED;
-               }
-
-               mrk = (struct xfrm_mark*)RTA_DATA(rthdr);
-               mrk->v = mark.value;
-               mrk->m = mark.mask;
+               return FAILED;
        }
 
        if (current->route)