chiark / gitweb /
rtnl: add link_get_flags
[elogind.git] / src / libsystemd-rtnl / rtnl-message.c
index 557e69017cf0f06eb021c089dbb91534afe2946b..8d62df965a199500925939abc22f4ec5fbddeafd 100644 (file)
@@ -19,6 +19,7 @@
   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>
@@ -35,6 +36,8 @@ struct sd_rtnl_message {
 
         struct nlmsghdr *hdr;
 
+        struct rtattr *current_container;
+
         struct rtattr *next_rta;
         size_t remaining_size;
 
@@ -67,12 +70,70 @@ static int message_new(sd_rtnl_message **ret, size_t initial_size) {
         return 0;
 }
 
-int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, unsigned int type, unsigned int flags, sd_rtnl_message **ret) {
+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;
+}
+
+int sd_rtnl_message_route_new(uint16_t nlmsg_type, unsigned char rtm_family,
+                              unsigned char rtm_dst_len, unsigned char rtm_src_len,
+                              unsigned char rtm_tos, unsigned char rtm_table,
+                              unsigned char rtm_scope, unsigned char rtm_protocol,
+                              unsigned char rtm_type, unsigned rtm_flags, sd_rtnl_message **ret) {
+        struct rtmsg *rtm;
+        int r;
+
+        assert_return(nlmsg_type == RTM_NEWROUTE || nlmsg_type == RTM_DELROUTE ||
+                      nlmsg_type == RTM_GETROUTE, -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);
+
+        rtm->rtm_family = rtm_family;
+        rtm->rtm_dst_len = rtm_dst_len;
+        rtm->rtm_src_len = rtm_src_len;
+        rtm->rtm_tos = rtm_tos;
+        rtm->rtm_table = rtm_table;
+        rtm->rtm_protocol = rtm_protocol;
+        rtm->rtm_scope = rtm_scope;
+        rtm->rtm_type = rtm_type;
+        rtm->rtm_flags = rtm_flags;
+
+        return 0;
+}
+
+int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, unsigned type, unsigned flags, sd_rtnl_message **ret) {
         struct ifinfomsg *ifi;
         int r;
 
-        assert_return(nlmsg_type == RTM_NEWLINK || nlmsg_type == RTM_DELLINK || nlmsg_type == RTM_GETLINK, -EINVAL);
-        assert_return(index > 0, -EINVAL);
+        assert_return(nlmsg_type == RTM_NEWLINK || nlmsg_type == RTM_DELLINK ||
+                      nlmsg_type == RTM_SETLINK || nlmsg_type == RTM_GETLINK, -EINVAL);
+        assert_return(nlmsg_type == RTM_NEWLINK || index > 0, -EINVAL);
         assert_return(ret, -EINVAL);
 
         r = message_new(ret, NLMSG_SPACE(sizeof(struct ifinfomsg)));
@@ -81,6 +142,8 @@ int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, unsigned int type,
 
         (*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);
 
@@ -144,23 +207,52 @@ int sd_rtnl_message_get_type(sd_rtnl_message *m, uint16_t *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(ifindex, -EINVAL);
+        assert_return(m->hdr->nlmsg_type == RTM_NEWLINK || m->hdr->nlmsg_type == RTM_DELLINK ||
+                      m->hdr->nlmsg_type == RTM_GETLINK || m->hdr->nlmsg_type == RTM_SETLINK, -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(flags, -EINVAL);
+        assert_return(m->hdr->nlmsg_type == RTM_NEWLINK || m->hdr->nlmsg_type == RTM_DELLINK ||
+                      m->hdr->nlmsg_type == RTM_GETLINK || m->hdr->nlmsg_type == RTM_SETLINK, -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_return(m, -EINVAL);
-        assert_return(m->hdr, -EINVAL);
-        assert_return(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len, -EINVAL);
-        assert_return(data, -EINVAL);
-        assert_return(data_length > 0, -EINVAL);
+        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 (without padding at the end) */
+        /* 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 between the old message and the new attrib,
-         * but no padding after)
+        /* get the new message size (with padding at the end)
          */
         message_length = m->hdr->nlmsg_len + RTA_ALIGN(rta_length);
 
@@ -175,13 +267,28 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data,
         /* update message size */
         m->hdr->nlmsg_len = message_length;
 
+        /* we are inside a container, extend it */
+        if (m->current_container)
+                m->current_container->rta_len = (unsigned char *) m->hdr +
+                                                m->hdr->nlmsg_len -
+                                                (unsigned char *) m->current_container;
+
         /* fill in the attribute */
         rta->rta_type = type;
         rta->rta_len = rta_length;
-        /* 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)
-         */
-        memcpy(RTA_DATA(rta), data, data_length);
+        if (!data) {
+                /* this is a container, set pointer */
+                m->current_container = rta;
+        } 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 */
+                memset(padding, '\0', (unsigned char *) m->hdr +
+                                      m->hdr->nlmsg_len -
+                                      (unsigned char *) padding);
+        }
 
         return 0;
 }
@@ -189,24 +296,49 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data,
 int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void *data) {
         uint16_t rtm_type;
         struct ifaddrmsg *ifa;
+        struct rtmsg *rtm;
 
         assert_return(m, -EINVAL);
         assert_return(data, -EINVAL);
 
         sd_rtnl_message_get_type(m, &rtm_type);
 
+        if (m->current_container) {
+                switch (rtm_type) {
+                        case RTM_NEWLINK:
+                        case RTM_SETLINK:
+                        case RTM_GETLINK:
+                        case RTM_DELLINK:
+                                switch (m->current_container->rta_type) {
+                                        case IFLA_LINKINFO:
+                                                switch (type) {
+                                                        case IFLA_INFO_KIND:
+                                                                return add_rtattr(m, type, data, strlen(data) + 1);
+                                                        default:
+                                                                return -ENOTSUP;
+                                                }
+                                        default:
+                                                return -ENOTSUP;
+                                }
+                        default:
+                                return -ENOTSUP;
+                }
+        }
+
         switch (rtm_type) {
                 case RTM_NEWLINK:
+                case RTM_SETLINK:
                 case RTM_DELLINK:
                 case RTM_GETLINK:
                         switch (type) {
                                 case IFLA_IFNAME:
+                                case IFLA_IFALIAS:
                                 case IFLA_QDISC:
                                         return add_rtattr(m, type, data, strlen(data) + 1);
+                                case IFLA_MASTER:
                                 case IFLA_MTU:
-                                        return add_rtattr(m, type, data, sizeof(unsigned int));
                                 case IFLA_LINK:
-                                        return add_rtattr(m, type, data, sizeof(int));
+                                        return add_rtattr(m, type, data, sizeof(uint32_t));
                                 case IFLA_STATS:
                                         return add_rtattr(m, type, data, sizeof(struct rtnl_link_stats));
                                 case IFLA_ADDRESS:
@@ -237,18 +369,96 @@ int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void *
                                 default:
                                         return -ENOTSUP;
                         }
+                case RTM_NEWROUTE:
+                case RTM_DELROUTE:
+                case RTM_GETROUTE:
+                        switch (type) {
+                                case RTA_DST:
+                                case RTA_SRC:
+                                case RTA_GATEWAY:
+                                        rtm = NLMSG_DATA(m->hdr);
+                                        switch (rtm->rtm_family) {
+                                                case AF_INET:
+                                                        return add_rtattr(m, type, data, sizeof(struct in_addr));
+                                                case AF_INET6:
+                                                        return add_rtattr(m, type, data, sizeof(struct in6_addr));
+                                                default:
+                                                        return -EINVAL;
+                                        }
+                                case RTA_TABLE:
+                                case RTA_PRIORITY:
+                                case RTA_IIF:
+                                case RTA_OIF:
+                                        return add_rtattr(m, type, data, sizeof(uint32_t));
+                                default:
+                                        return -ENOTSUP;
+                        }
                 default:
                         return -ENOTSUP;
         }
 }
 
-static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
+int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) {
+        uint16_t rtm_type;
+
         assert_return(m, -EINVAL);
-        assert_return(data, -EINVAL);
+        assert_return(!m->current_container, -EINVAL);
+
+        sd_rtnl_message_get_type(m, &rtm_type);
+
+        switch (rtm_type) {
+                case RTM_NEWLINK:
+                case RTM_SETLINK:
+                case RTM_GETLINK:
+                case RTM_DELLINK:
+                        if (type == IFLA_LINKINFO)
+                                return add_rtattr(m, type, NULL, 0);
+                        else
+                                return -ENOTSUP;
+                default:
+                        return -ENOTSUP;
+        }
+
+        return 0;
+}
+
+int sd_rtnl_message_close_container(sd_rtnl_message *m) {
+        assert_return(m, -EINVAL);
+        assert_return(m->current_container, -EINVAL);
+
+        m->current_container = NULL;
+
+        return 0;
+}
+
+static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
+        uint16_t rtm_type;
+        int r;
+
+        assert(m);
+        assert(m->next_rta);
+        assert(type);
+        assert(data);
 
         if (!RTA_OK(m->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;
+
+        switch (rtm_type) {
+                case RTM_NEWLINK:
+                case RTM_GETLINK:
+                case RTM_SETLINK:
+                case RTM_DELLINK:
+                        if (m->next_rta->rta_type == IFLA_LINKINFO) {
+                                return -EINVAL;
+                        }
+        }
+
         *data = RTA_DATA(m->next_rta);
         *type = m->next_rta->rta_type;
 
@@ -259,14 +469,18 @@ static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
 
 int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
         uint16_t rtm_type;
+        int r;
 
         assert_return(m, -EINVAL);
         assert_return(data, -EINVAL);
 
-        sd_rtnl_message_get_type(m, &rtm_type);
+        r = sd_rtnl_message_get_type(m, &rtm_type);
+        if (r < 0)
+                return r;
 
         switch (rtm_type) {
                 case RTM_NEWLINK:
+                case RTM_SETLINK:
                 case RTM_DELLINK:
                 case RTM_GETLINK:
                         if (!m->next_rta) {
@@ -275,7 +489,7 @@ int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data)
                                 m->next_rta = IFLA_RTA(ifi);
                                 m->remaining_size = IFLA_PAYLOAD(m->hdr);
                         }
-                        break;;
+                        break;
                 case RTM_NEWADDR:
                 case RTM_DELADDR:
                 case RTM_GETADDR:
@@ -283,9 +497,19 @@ int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data)
                                 struct ifaddrmsg *ifa = NLMSG_DATA(m->hdr);
 
                                 m->next_rta = IFA_RTA(ifa);
-                                m->remaining_size = IFLA_PAYLOAD(m->hdr);
+                                m->remaining_size = IFA_PAYLOAD(m->hdr);
+                        }
+                        break;
+                case RTM_NEWROUTE:
+                case RTM_DELROUTE:
+                case RTM_GETROUTE:
+                        if (!m->next_rta) {
+                                struct rtmesg *rtm = NLMSG_DATA(m->hdr);
+
+                                m->next_rta = RTM_RTA(rtm);
+                                m->remaining_size = RTM_PAYLOAD(m->hdr);
                         }
-                        break;;
+                        break;
                 default:
                         return -ENOTSUP;
         }
@@ -293,16 +517,16 @@ int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data)
         return message_read(m, type, data);
 }
 
-int message_get_serial(sd_rtnl_message *m) {
+uint32_t message_get_serial(sd_rtnl_message *m) {
         assert(m);
 
         return m->hdr->nlmsg_seq;
 }
 
-int message_get_errno(sd_rtnl_message *m) {
+int sd_rtnl_message_get_errno(sd_rtnl_message *m) {
         struct nlmsgerr *err;
 
-        assert(m);
+        assert_return(m, -EINVAL);
 
         if (m->hdr->nlmsg_type != NLMSG_ERROR)
                 return 0;
@@ -344,13 +568,19 @@ static int message_receive_need(sd_rtnl *rtnl, size_t *need) {
 
 /* 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_return(nl, -EINVAL);
         assert_return(m, -EINVAL);
 
         k = sendto(nl->fd, m->hdr, m->hdr->nlmsg_len,
-                        0, &nl->sockaddr.sa, sizeof(nl->sockaddr));
+                        0, &addr.sa, sizeof(addr));
         if (k < 0)
                 return (errno == EAGAIN) ? 0 : -errno;
 
@@ -364,7 +594,11 @@ int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
  */
 int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) {
         sd_rtnl_message *m;
-        socklen_t addr_len = sizeof(nl->sockaddr);
+        union {
+                struct sockaddr sa;
+                struct sockaddr_nl nl;
+        } addr;
+        socklen_t addr_len;
         int r;
         ssize_t k;
         size_t need;
@@ -380,22 +614,24 @@ int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) {
         if (r < 0)
                 return r;
 
+        addr_len = sizeof(addr);
+
         k = recvfrom(nl->fd, m->hdr, need,
-                        0, &nl->sockaddr.sa, &addr_len);
+                        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(nl->sockaddr.nl) ||
-                        nl->sockaddr.nl.nl_family != AF_NETLINK)
+        else if (addr_len != sizeof(addr.nl) ||
+                        addr.nl.nl_family != AF_NETLINK)
                 k = -EIO; /* not a netlink message */
-        else if (nl->sockaddr.nl.nl_pid != 0)
+        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 ((pid_t) m->hdr->nlmsg_pid != getpid())
-                k = 0; /* not for us */
+        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) {
@@ -403,22 +639,23 @@ int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) {
                         case NLMSG_ERROR:
                                 if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
                                         k = -EIO;
-                                break;;
+                                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;
-                                break;;
+                                break;
                         case RTM_NEWADDR:
                         case RTM_DELADDR:
                         case RTM_GETADDR:
                                 if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifaddrmsg)))
                                         k = -EIO;
-                                break;;
+                                break;
                         case NLMSG_NOOP:
                                 k = 0;
-                                break;;
+                                break;
                         default:
                                 k = 0; /* ignoring message of unknown type */
                 }