chiark / gitweb /
libsystemd-rtnl: merge into libsystemd
[elogind.git] / src / libsystemd-rtnl / rtnl-message.c
diff --git a/src/libsystemd-rtnl/rtnl-message.c b/src/libsystemd-rtnl/rtnl-message.c
deleted file mode 100644 (file)
index 517df61..0000000
+++ /dev/null
@@ -1,887 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
-  This file is part of systemd.
-
-  Copyright 2013 Tom Gundersen <teg@jklm.no>
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd 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
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <linux/rtnetlink.h>
-#include <netinet/in.h>
-#include <netinet/ether.h>
-#include <stdbool.h>
-#include <unistd.h>
-
-#include "util.h"
-#include "refcnt.h"
-
-#include "sd-rtnl.h"
-#include "rtnl-internal.h"
-
-struct sd_rtnl_message {
-        RefCount n_ref;
-
-        struct nlmsghdr *hdr;
-        size_t container_offset; /* offset from hdr to container start */
-        size_t next_rta_offset; /* offset from hdr to next rta */
-
-        bool sealed:1;
-};
-
-#define CURRENT_CONTAINER(m) ((m)->container_offset ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offset) : NULL)
-#define NEXT_RTA(m) ((struct rtattr*)((uint8_t*)(m)->hdr + (m)->next_rta_offset))
-#define UPDATE_RTA(m, new) (m)->next_rta_offset = (uint8_t*)(new) - (uint8_t*)(m)->hdr;
-
-static int message_new(sd_rtnl_message **ret, size_t initial_size) {
-        sd_rtnl_message *m;
-
-        assert_return(ret, -EINVAL);
-        assert_return(initial_size >= sizeof(struct nlmsghdr), -EINVAL);
-
-        m = new0(sd_rtnl_message, 1);
-        if (!m)
-                return -ENOMEM;
-
-        m->hdr = malloc0(initial_size);
-        if (!m->hdr) {
-                free(m);
-                return -ENOMEM;
-        }
-
-        m->n_ref = REFCNT_INIT;
-
-        m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
-        m->sealed = false;
-
-        *ret = m;
-
-        return 0;
-}
-
-int message_new_synthetic_error(int error, uint32_t serial, sd_rtnl_message **ret) {
-        struct nlmsgerr *err;
-        int r;
-
-        assert(error <= 0);
-
-        r = message_new(ret, NLMSG_SPACE(sizeof(struct nlmsgerr)));
-        if (r < 0)
-                return r;
-
-        (*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
-        (*ret)->hdr->nlmsg_type = NLMSG_ERROR;
-        (*ret)->hdr->nlmsg_seq = serial;
-
-        err = NLMSG_DATA((*ret)->hdr);
-
-        err->error = error;
-
-        return 0;
-}
-
-bool message_type_is_route(uint16_t type) {
-        switch (type) {
-                case RTM_NEWROUTE:
-                case RTM_GETROUTE:
-                case RTM_DELROUTE:
-                        return true;
-                default:
-                        return false;
-        }
-}
-
-bool message_type_is_link(uint16_t type) {
-        switch (type) {
-                case RTM_NEWLINK:
-                case RTM_SETLINK:
-                case RTM_GETLINK:
-                case RTM_DELLINK:
-                        return true;
-                default:
-                        return false;
-        }
-}
-
-bool message_type_is_addr(uint16_t type) {
-        switch (type) {
-                case RTM_NEWADDR:
-                case RTM_GETADDR:
-                case RTM_DELADDR:
-                        return true;
-                default:
-                        return false;
-        }
-}
-
-int sd_rtnl_message_route_set_dst_prefixlen(sd_rtnl_message *m, unsigned char prefixlen) {
-        struct rtmsg *rtm;
-
-        rtm = NLMSG_DATA(m->hdr);
-
-        rtm->rtm_dst_len = prefixlen;
-
-        return 0;
-}
-
-int sd_rtnl_message_route_new(uint16_t nlmsg_type, unsigned char rtm_family,
-                              sd_rtnl_message **ret) {
-        struct rtmsg *rtm;
-        int r;
-
-        assert_return(message_type_is_route(nlmsg_type), -EINVAL);
-        assert_return(rtm_family == AF_INET || rtm_family == AF_INET6, -EINVAL);
-        assert_return(ret, -EINVAL);
-
-        r = message_new(ret, NLMSG_SPACE(sizeof(struct rtmsg)));
-        if (r < 0)
-                return r;
-
-        (*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
-        (*ret)->hdr->nlmsg_type = nlmsg_type;
-        if (nlmsg_type == RTM_NEWROUTE)
-                (*ret)->hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
-
-        rtm = NLMSG_DATA((*ret)->hdr);
-
-        UPDATE_RTA(*ret, RTM_RTA(rtm));
-
-        rtm->rtm_family = rtm_family;
-        rtm->rtm_scope = RT_SCOPE_UNIVERSE;
-        rtm->rtm_type = RTN_UNICAST;
-        rtm->rtm_table = RT_TABLE_MAIN;
-        rtm->rtm_protocol = RTPROT_BOOT;
-
-        return 0;
-}
-
-int sd_rtnl_message_link_set_flags(sd_rtnl_message *m, unsigned flags) {
-        struct ifinfomsg *ifi;
-
-        ifi = NLMSG_DATA(m->hdr);
-
-        ifi->ifi_flags = flags;
-
-        return 0;
-}
-
-int sd_rtnl_message_link_set_type(sd_rtnl_message *m, unsigned type) {
-        struct ifinfomsg *ifi;
-
-        ifi = NLMSG_DATA(m->hdr);
-
-        ifi->ifi_type = type;
-
-        return 0;
-}
-
-int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, sd_rtnl_message **ret) {
-        struct ifinfomsg *ifi;
-        int r;
-
-        assert_return(message_type_is_link(nlmsg_type), -EINVAL);
-        assert_return(nlmsg_type == RTM_NEWLINK || index > 0, -EINVAL);
-        assert_return(ret, -EINVAL);
-
-        r = message_new(ret, NLMSG_SPACE(sizeof(struct ifinfomsg)));
-        if (r < 0)
-                return r;
-
-        (*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
-        (*ret)->hdr->nlmsg_type = nlmsg_type;
-        if (nlmsg_type == RTM_NEWLINK)
-                (*ret)->hdr->nlmsg_flags |= NLM_F_CREATE;
-
-        ifi = NLMSG_DATA((*ret)->hdr);
-
-        ifi->ifi_family = AF_UNSPEC;
-        ifi->ifi_index = index;
-        ifi->ifi_change = 0xffffffff;
-
-        UPDATE_RTA(*ret, IFLA_RTA(ifi));
-
-        return 0;
-}
-
-int sd_rtnl_message_addr_new(uint16_t nlmsg_type, int index, unsigned char family, unsigned char prefixlen, unsigned char flags, unsigned char scope, sd_rtnl_message **ret) {
-        struct ifaddrmsg *ifa;
-        int r;
-
-        assert_return(message_type_is_addr(nlmsg_type), -EINVAL);
-        assert_return(index > 0, -EINVAL);
-        assert_return(ret, -EINVAL);
-
-        r = message_new(ret, NLMSG_SPACE(sizeof(struct ifaddrmsg)));
-        if (r < 0)
-                return r;
-
-        (*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
-        (*ret)->hdr->nlmsg_type = nlmsg_type;
-
-        ifa = NLMSG_DATA((*ret)->hdr);
-
-        ifa->ifa_family = family;
-        ifa->ifa_prefixlen = prefixlen;
-        ifa->ifa_flags = flags;
-        ifa->ifa_scope = scope;
-        ifa->ifa_index = index;
-
-        UPDATE_RTA(*ret, IFA_RTA(ifa));
-
-        return 0;
-}
-
-sd_rtnl_message *sd_rtnl_message_ref(sd_rtnl_message *m) {
-        if (m)
-                assert_se(REFCNT_INC(m->n_ref) >= 2);
-
-        return m;
-}
-
-sd_rtnl_message *sd_rtnl_message_unref(sd_rtnl_message *m) {
-        if (m && REFCNT_DEC(m->n_ref) <= 0) {
-                free(m->hdr);
-                free(m);
-        }
-
-        return NULL;
-}
-
-int sd_rtnl_message_get_type(sd_rtnl_message *m, uint16_t *type) {
-        assert_return(m, -EINVAL);
-        assert_return(type, -EINVAL);
-
-        *type = m->hdr->nlmsg_type;
-
-        return 0;
-}
-
-int sd_rtnl_message_link_get_ifindex(sd_rtnl_message *m, int *ifindex) {
-        struct ifinfomsg *ifi;
-
-        assert_return(m, -EINVAL);
-        assert_return(m->hdr, -EINVAL);
-        assert_return(message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
-        assert_return(ifindex, -EINVAL);
-
-        ifi = NLMSG_DATA(m->hdr);
-
-        *ifindex = ifi->ifi_index;
-
-        return 0;
-}
-
-int sd_rtnl_message_link_get_flags(sd_rtnl_message *m, unsigned *flags) {
-        struct ifinfomsg *ifi;
-
-        assert_return(m, -EINVAL);
-        assert_return(m->hdr, -EINVAL);
-        assert_return(message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
-        assert_return(flags, -EINVAL);
-
-        ifi = NLMSG_DATA(m->hdr);
-
-        *flags = ifi->ifi_flags;
-
-        return 0;
-}
-
-/* If successful the updated message will be correctly aligned, if
-   unsuccessful the old message is untouched. */
-static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data, size_t data_length) {
-        uint32_t rta_length, message_length;
-        struct nlmsghdr *new_hdr;
-        struct rtattr *rta;
-        char *padding;
-
-        assert(m);
-        assert(m->hdr);
-        assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
-        assert(!data || data_length > 0);
-
-        /* get the size of the new rta attribute (with padding at the end) */
-        rta_length = RTA_LENGTH(data_length);
-
-        /* get the new message size (with padding at the end) */
-        message_length = m->hdr->nlmsg_len + RTA_ALIGN(rta_length);
-
-        /* realloc to fit the new attribute */
-        new_hdr = realloc(m->hdr, message_length);
-        if (!new_hdr)
-                return -ENOMEM;
-        m->hdr = new_hdr;
-
-        /* get pointer to the attribute we are about to add */
-        rta = (struct rtattr *) ((uint8_t *) m->hdr + m->hdr->nlmsg_len);
-
-        /* if we are inside a container, extend it */
-        if (CURRENT_CONTAINER(m))
-                CURRENT_CONTAINER(m)->rta_len += message_length - m->hdr->nlmsg_len;
-
-        /* fill in the attribute */
-        rta->rta_type = type;
-        rta->rta_len = rta_length;
-        if (!data) {
-                /* this is the start of a new container */
-                m->container_offset = m->hdr->nlmsg_len;
-        } else {
-                /* we don't deal with the case where the user lies about the type
-                 * and gives us too little data (so don't do that)
-                */
-                padding = mempcpy(RTA_DATA(rta), data, data_length);
-                /* make sure also the padding at the end of the message is initialized */
-                memzero(padding,
-                        (uint8_t *) m->hdr + message_length - (uint8_t *) padding);
-        }
-
-        /* update message size */
-        m->hdr->nlmsg_len = message_length;
-
-        return 0;
-}
-
-int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const char *data) {
-        uint16_t rtm_type;
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(data, -EINVAL);
-
-        r = sd_rtnl_message_get_type(m, &rtm_type);
-        if (r < 0)
-                return r;
-
-        /* check that the type is correct */
-        switch (rtm_type) {
-                case RTM_NEWLINK:
-                case RTM_SETLINK:
-                case RTM_GETLINK:
-                case RTM_DELLINK:
-                        if (CURRENT_CONTAINER(m)) {
-                                if (CURRENT_CONTAINER(m)->rta_type != IFLA_LINKINFO ||
-                                    type != IFLA_INFO_KIND)
-                                        return -ENOTSUP;
-                        } else {
-                                switch (type) {
-                                        case IFLA_IFNAME:
-                                        case IFLA_IFALIAS:
-                                        case IFLA_QDISC:
-                                                break;
-                                        default:
-                                                return -ENOTSUP;
-                                }
-                        }
-                        break;
-                case RTM_NEWADDR:
-                case RTM_GETADDR:
-                case RTM_DELADDR:
-                        if (type != IFA_LABEL)
-                                return -ENOTSUP;
-                        break;
-                default:
-                        return -ENOTSUP;
-        }
-
-        r = add_rtattr(m, type, data, strlen(data) + 1);
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
-int sd_rtnl_message_append_u32(sd_rtnl_message *m, unsigned short type, uint32_t data) {
-        uint16_t rtm_type;
-        int r;
-
-        assert_return(m, -EINVAL);
-
-        r = sd_rtnl_message_get_type(m, &rtm_type);
-        if (r < 0)
-                return r;
-
-        /* check that the type is correct */
-        switch (rtm_type) {
-                case RTM_NEWLINK:
-                case RTM_SETLINK:
-                case RTM_GETLINK:
-                case RTM_DELLINK:
-                        switch (type) {
-                                case IFLA_MASTER:
-                                case IFLA_MTU:
-                                case IFLA_LINK:
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                        break;
-                case RTM_NEWROUTE:
-                case RTM_GETROUTE:
-                case RTM_DELROUTE:
-                        switch (type) {
-                                case RTA_TABLE:
-                                case RTA_PRIORITY:
-                                case RTA_IIF:
-                                case RTA_OIF:
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                        break;
-                default:
-                        return -ENOTSUP;
-        }
-
-        r = add_rtattr(m, type, &data, sizeof(uint32_t));
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
-int sd_rtnl_message_append_in_addr(sd_rtnl_message *m, unsigned short type, const struct in_addr *data) {
-        struct ifaddrmsg *ifa;
-        struct rtmsg *rtm;
-        uint16_t rtm_type;
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(data, -EINVAL);
-
-        r = sd_rtnl_message_get_type(m, &rtm_type);
-        if (r < 0)
-                return r;
-
-        /* check that the type is correct */
-        switch (rtm_type) {
-                case RTM_NEWADDR:
-                case RTM_GETADDR:
-                case RTM_DELADDR:
-                        switch (type) {
-                                case IFA_ADDRESS:
-                                case IFA_LOCAL:
-                                case IFA_BROADCAST:
-                                case IFA_ANYCAST:
-                                        ifa = NLMSG_DATA(m->hdr);
-
-                                        if (ifa->ifa_family != AF_INET)
-                                                return -EINVAL;
-
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                        break;
-                case RTM_NEWROUTE:
-                case RTM_GETROUTE:
-                case RTM_DELROUTE:
-                        switch (type) {
-                                case RTA_DST:
-                                case RTA_SRC:
-                                case RTA_GATEWAY:
-                                        rtm = NLMSG_DATA(m->hdr);
-
-                                        if (rtm->rtm_family != AF_INET)
-                                                return -EINVAL;
-
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                        break;
-                default:
-                        return -ENOTSUP;
-        }
-
-        r = add_rtattr(m, type, data, sizeof(struct in_addr));
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
-int sd_rtnl_message_append_in6_addr(sd_rtnl_message *m, unsigned short type, const struct in6_addr *data) {
-        struct ifaddrmsg *ifa;
-        struct rtmsg *rtm;
-        uint16_t rtm_type;
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(data, -EINVAL);
-
-        r = sd_rtnl_message_get_type(m, &rtm_type);
-        if (r < 0)
-                return r;
-
-        /* check that the type is correct */
-        switch (rtm_type) {
-                case RTM_NEWADDR:
-                case RTM_GETADDR:
-                case RTM_DELADDR:
-                        switch (type) {
-                                case IFA_ADDRESS:
-                                case IFA_LOCAL:
-                                case IFA_BROADCAST:
-                                case IFA_ANYCAST:
-                                        ifa = NLMSG_DATA(m->hdr);
-
-                                        if (ifa->ifa_family != AF_INET6)
-                                                return -EINVAL;
-
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                        break;
-                case RTM_NEWROUTE:
-                case RTM_GETROUTE:
-                case RTM_DELROUTE:
-                        switch (type) {
-                                case RTA_DST:
-                                case RTA_SRC:
-                                case RTA_GATEWAY:
-                                        rtm = NLMSG_DATA(m->hdr);
-
-                                        if (rtm->rtm_family != AF_INET6)
-                                                return -EINVAL;
-
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                default:
-                        return -ENOTSUP;
-        }
-
-        r = add_rtattr(m, type, data, sizeof(struct in6_addr));
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
-int sd_rtnl_message_append_ether_addr(sd_rtnl_message *m, unsigned short type, const struct ether_addr *data) {
-        uint16_t rtm_type;
-        int r;
-
-        assert_return(m, -EINVAL);
-        assert_return(data, -EINVAL);
-
-        sd_rtnl_message_get_type(m, &rtm_type);
-
-        switch (rtm_type) {
-                case RTM_NEWLINK:
-                case RTM_SETLINK:
-                case RTM_DELLINK:
-                case RTM_GETLINK:
-                        switch (type) {
-                                case IFLA_ADDRESS:
-                                case IFLA_BROADCAST:
-                                        break;
-                                default:
-                                        return -ENOTSUP;
-                        }
-                        break;
-                default:
-                        return -ENOTSUP;
-        }
-
-        r = add_rtattr(m, type, data, ETH_ALEN);
-        if (r < 0)
-                return r;
-
-        return 0;
-}
-
-int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) {
-        uint16_t rtm_type;
-
-        assert_return(m, -EINVAL);
-        assert_return(!CURRENT_CONTAINER(m), -EINVAL);
-
-        sd_rtnl_message_get_type(m, &rtm_type);
-
-        if (message_type_is_link(rtm_type)) {
-                if (type == IFLA_LINKINFO)
-                        return add_rtattr(m, type, NULL, 0);
-                else
-                        return -ENOTSUP;
-        } else
-                return -ENOTSUP;
-
-        return 0;
-}
-
-int sd_rtnl_message_close_container(sd_rtnl_message *m) {
-        assert_return(m, -EINVAL);
-        assert_return(CURRENT_CONTAINER(m), -EINVAL);
-
-        m->container_offset = 0;
-
-        return 0;
-}
-
-int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
-        size_t remaining_size;
-        uint16_t rtm_type;
-        int r;
-
-        assert(m);
-        assert(m->next_rta_offset);
-        assert(type);
-        assert(data);
-
-        remaining_size = m->hdr->nlmsg_len - m->next_rta_offset;
-
-        if (!RTA_OK(NEXT_RTA(m), remaining_size))
-                return 0;
-
-        /* make sure we don't try to read a container
-         * TODO: add support for entering containers for reading */
-        r = sd_rtnl_message_get_type(m, &rtm_type);
-        if (r < 0)
-                return r;
-
-        if (message_type_is_link(rtm_type) &&
-            NEXT_RTA(m)->rta_type == IFLA_LINKINFO)
-               return -EINVAL;
-
-        *data = RTA_DATA(NEXT_RTA(m));
-        *type = NEXT_RTA(m)->rta_type;
-
-        UPDATE_RTA(m, RTA_NEXT(NEXT_RTA(m), remaining_size));
-
-        return 1;
-}
-
-uint32_t message_get_serial(sd_rtnl_message *m) {
-        assert(m);
-        assert(m->hdr);
-
-        return m->hdr->nlmsg_seq;
-}
-
-int sd_rtnl_message_get_errno(sd_rtnl_message *m) {
-        struct nlmsgerr *err;
-
-        assert_return(m, -EINVAL);
-        assert_return(m->hdr, -EINVAL);
-
-        if (m->hdr->nlmsg_type != NLMSG_ERROR)
-                return 0;
-
-        err = NLMSG_DATA(m->hdr);
-
-        return err->error;
-}
-
-int message_seal(sd_rtnl *nl, sd_rtnl_message *m) {
-        assert(nl);
-        assert(m);
-        assert(m->hdr);
-
-        if (m->sealed)
-                return -EPERM;
-
-        m->hdr->nlmsg_seq = nl->serial++;
-        m->sealed = true;
-
-        return 0;
-}
-
-static int message_receive_need(sd_rtnl *rtnl, size_t *need) {
-        assert(rtnl);
-        assert(need);
-
-        /* ioctl(rtnl->fd, FIONREAD, &need)
-           Does not appear to work on netlink sockets. libnl uses
-           MSG_PEEK instead. I don't know if that is worth the
-           extra roundtrip.
-
-           For now we simply use the maximum message size the kernel
-           may use (NLMSG_GOODSIZE), and then realloc to the actual
-           size after reading the message (hence avoiding huge memory
-           usage in case many small messages are kept around) */
-        *need = page_size();
-        if (*need > 8192UL)
-                *need = 8192UL;
-
-        return 0;
-}
-
-/* returns the number of bytes sent, or a negative error code */
-int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
-        union {
-                struct sockaddr sa;
-                struct sockaddr_nl nl;
-        } addr = {
-                .nl.nl_family = AF_NETLINK,
-        };
-        ssize_t k;
-
-        assert(nl);
-        assert(m);
-        assert(m->hdr);
-
-        k = sendto(nl->fd, m->hdr, m->hdr->nlmsg_len,
-                        0, &addr.sa, sizeof(addr));
-        if (k < 0)
-                return (errno == EAGAIN) ? 0 : -errno;
-
-        return k;
-}
-
-/* On success, the number of bytes received is returned and *ret points to the received message
- * which has a valid header and the correct size.
- * If nothing useful was received 0 is returned.
- * On failure, a negative error code is returned.
- */
-int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) {
-        sd_rtnl_message *m;
-        union {
-                struct sockaddr sa;
-                struct sockaddr_nl nl;
-        } addr;
-        socklen_t addr_len;
-        int r;
-        ssize_t k;
-        size_t need;
-
-        assert(nl);
-        assert(ret);
-
-        r = message_receive_need(nl, &need);
-        if (r < 0)
-                return r;
-
-        r = message_new(&m, need);
-        if (r < 0)
-                return r;
-
-        addr_len = sizeof(addr);
-
-        k = recvfrom(nl->fd, m->hdr, need,
-                        0, &addr.sa, &addr_len);
-        if (k < 0)
-                k = (errno == EAGAIN) ? 0 : -errno; /* no data */
-        else if (k == 0)
-                k = -ECONNRESET; /* connection was closed by the kernel */
-        else if (addr_len != sizeof(addr.nl) ||
-                        addr.nl.nl_family != AF_NETLINK)
-                k = -EIO; /* not a netlink message */
-        else if (addr.nl.nl_pid != 0)
-                k = 0; /* not from the kernel */
-        else if ((size_t) k < sizeof(struct nlmsghdr) ||
-                        (size_t) k < m->hdr->nlmsg_len)
-                k = -EIO; /* too small (we do accept too big though) */
-        else if (m->hdr->nlmsg_pid && m->hdr->nlmsg_pid != nl->sockaddr.nl.nl_pid)
-                k = 0; /* not broadcast and not for us */
-
-        if (k > 0)
-                switch (m->hdr->nlmsg_type) {
-                        struct ifinfomsg *ifi;
-                        struct ifaddrmsg *ifa;
-                        struct rtmsg *rtm;
-
-                        /* check that the size matches the message type */
-                        case NLMSG_ERROR:
-                                if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
-                                        k = -EIO;
-                                break;
-                        case RTM_NEWLINK:
-                        case RTM_SETLINK:
-                        case RTM_DELLINK:
-                        case RTM_GETLINK:
-                                if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg)))
-                                        k = -EIO;
-                                else {
-                                        ifi = NLMSG_DATA(m->hdr);
-                                        UPDATE_RTA(m, IFLA_RTA(ifi));
-                                }
-                                break;
-                        case RTM_NEWADDR:
-                        case RTM_DELADDR:
-                        case RTM_GETADDR:
-                                if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifaddrmsg)))
-                                        k = -EIO;
-                                else {
-                                        ifa = NLMSG_DATA(m->hdr);
-                                        UPDATE_RTA(m, IFA_RTA(ifa));
-                                }
-                                break;
-                        case RTM_NEWROUTE:
-                        case RTM_DELROUTE:
-                        case RTM_GETROUTE:
-                                if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtmsg)))
-                                        k = -EIO;
-                                else {
-                                        rtm = NLMSG_DATA(m->hdr);
-                                        UPDATE_RTA(m, RTM_RTA(rtm));
-                                }
-                                break;
-                        case NLMSG_NOOP:
-                                k = 0;
-                                break;
-                        default:
-                                k = 0; /* ignoring message of unknown type */
-                }
-
-        if (k <= 0)
-                sd_rtnl_message_unref(m);
-        else {
-                /* we probably allocated way too much memory, give it back */
-                m->hdr = realloc(m->hdr, m->hdr->nlmsg_len);
-                *ret = m;
-        }
-
-        return k;
-}
-
-int sd_rtnl_message_rewind(sd_rtnl_message *m) {
-        struct ifinfomsg *ifi;
-        struct ifaddrmsg *ifa;
-        struct rtmsg *rtm;
-
-        assert_return(m, -EINVAL);
-        assert_return(m->hdr, -EINVAL);
-
-        switch(m->hdr->nlmsg_type) {
-                case RTM_NEWLINK:
-                case RTM_SETLINK:
-                case RTM_GETLINK:
-                case RTM_DELLINK:
-                        ifi = NLMSG_DATA(m->hdr);
-                        UPDATE_RTA(m, IFLA_RTA(ifi));
-
-                        break;
-                case RTM_NEWADDR:
-                case RTM_GETADDR:
-                case RTM_DELADDR:
-                        ifa = NLMSG_DATA(m->hdr);
-                        UPDATE_RTA(m, IFA_RTA(ifa));
-
-                        break;
-                case RTM_NEWROUTE:
-                case RTM_GETROUTE:
-                case RTM_DELROUTE:
-                        rtm = NLMSG_DATA(m->hdr);
-                        UPDATE_RTA(m, RTM_RTA(rtm));
-
-                        break;
-                default:
-                        return -ENOTSUP;
-        }
-
-        return 0;
-}