chiark / gitweb /
sd-rtnl: add sd_rtnl_message_{new_neigh,neigh_get_{family,ifindex}}
[elogind.git] / src / libsystemd / sd-rtnl / rtnl-message.c
index d611207deab2c76bd157aa279b451c699fc8f89b..84ebf65d8ebab93f430cf52a9fb47f454101ebf9 100644 (file)
 #include <netinet/ether.h>
 #include <stdbool.h>
 #include <unistd.h>
-#include <linux/netlink.h>
-#include <linux/veth.h>
-#include <linux/if.h>
-#include <linux/ip.h>
-#include <linux/if_tunnel.h>
-#include <linux/if_bridge.h>
 
 #include "util.h"
 #include "refcnt.h"
@@ -42,6 +36,8 @@
 #define GET_CONTAINER(m, i) ((i) < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offsets[i]) : NULL)
 #define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr;
 
+#define RTA_TYPE(rta) ((rta)->rta_type & NLA_TYPE_MASK)
+
 static int message_new_empty(sd_rtnl *rtnl, sd_rtnl_message **ret) {
         sd_rtnl_message *m;
 
@@ -132,8 +128,24 @@ int sd_rtnl_message_route_set_scope(sd_rtnl_message *m, unsigned char scope) {
         return 0;
 }
 
+int sd_rtnl_message_route_get_family(sd_rtnl_message *m, int *family) {
+        struct rtmsg *rtm;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(rtnl_message_type_is_route(m->hdr->nlmsg_type), -EINVAL);
+        assert_return(family, -EINVAL);
+
+        rtm = NLMSG_DATA(m->hdr);
+
+        *family = rtm->rtm_family;
+
+        return 0;
+}
+
 int sd_rtnl_message_new_route(sd_rtnl *rtnl, sd_rtnl_message **ret,
-                              uint16_t nlmsg_type, unsigned char rtm_family) {
+                              uint16_t nlmsg_type, int rtm_family,
+                              unsigned char rtm_protocol) {
         struct rtmsg *rtm;
         int r;
 
@@ -154,7 +166,60 @@ int sd_rtnl_message_new_route(sd_rtnl *rtnl, sd_rtnl_message **ret,
         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
         rtm->rtm_type = RTN_UNICAST;
         rtm->rtm_table = RT_TABLE_MAIN;
-        rtm->rtm_protocol = RTPROT_BOOT;
+        rtm->rtm_protocol = rtm_protocol;
+
+        return 0;
+}
+
+int sd_rtnl_message_neigh_get_family(sd_rtnl_message *m, int *family) {
+        struct ndmsg *ndm;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(rtnl_message_type_is_neigh(m->hdr->nlmsg_type), -EINVAL);
+        assert_return(family, -EINVAL);
+
+        ndm = NLMSG_DATA(m->hdr);
+
+        *family = ndm->ndm_family;
+
+        return 0;
+}
+
+int sd_rtnl_message_neigh_get_ifindex(sd_rtnl_message *m, int *index) {
+        struct ndmsg *ndm;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(rtnl_message_type_is_neigh(m->hdr->nlmsg_type), -EINVAL);
+        assert_return(index, -EINVAL);
+
+        ndm = NLMSG_DATA(m->hdr);
+
+        *index = ndm->ndm_ifindex;
+
+        return 0;
+}
+
+int sd_rtnl_message_new_neigh(sd_rtnl *rtnl, sd_rtnl_message **ret, uint16_t nlmsg_type, int index, int ndm_family) {
+        struct ndmsg *ndm;
+        int r;
+
+        assert_return(rtnl_message_type_is_neigh(nlmsg_type), -EINVAL);
+        assert_return(ndm_family == AF_INET || ndm_family == AF_INET6, -EINVAL);
+        assert_return(ret, -EINVAL);
+
+        r = message_new(rtnl, ret, nlmsg_type);
+        if (r < 0)
+                return r;
+
+        if (nlmsg_type == RTM_NEWNEIGH)
+                (*ret)->hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_APPEND;
+
+        ndm = NLMSG_DATA((*ret)->hdr);
+
+        ndm->ndm_family = ndm_family;
+        ndm->ndm_ifindex = index;
 
         return 0;
 }
@@ -189,6 +254,20 @@ int sd_rtnl_message_link_set_type(sd_rtnl_message *m, unsigned type) {
         return 0;
 }
 
+int sd_rtnl_message_link_set_family(sd_rtnl_message *m, unsigned family) {
+        struct ifinfomsg *ifi;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(rtnl_message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
+
+        ifi = NLMSG_DATA(m->hdr);
+
+        ifi->ifi_family = family;
+
+        return 0;
+}
+
 int sd_rtnl_message_new_link(sd_rtnl *rtnl, sd_rtnl_message **ret,
                              uint16_t nlmsg_type, int index) {
         struct ifinfomsg *ifi;
@@ -216,9 +295,10 @@ int sd_rtnl_message_new_link(sd_rtnl *rtnl, sd_rtnl_message **ret,
 int sd_rtnl_message_request_dump(sd_rtnl_message *m, int dump) {
         assert_return(m, -EINVAL);
         assert_return(m->hdr, -EINVAL);
-        assert_return(m->hdr->nlmsg_type == RTM_GETLINK ||
-                      m->hdr->nlmsg_type == RTM_GETADDR ||
-                      m->hdr->nlmsg_type == RTM_GETROUTE,
+        assert_return(m->hdr->nlmsg_type == RTM_GETLINK  ||
+                      m->hdr->nlmsg_type == RTM_GETADDR  ||
+                      m->hdr->nlmsg_type == RTM_GETROUTE ||
+                      m->hdr->nlmsg_type == RTM_GETNEIGH,
                       -EINVAL);
 
         if (dump)
@@ -275,7 +355,7 @@ int sd_rtnl_message_addr_set_scope(sd_rtnl_message *m, unsigned char scope) {
         return 0;
 }
 
-int sd_rtnl_message_addr_get_family(sd_rtnl_message *m, unsigned char *family) {
+int sd_rtnl_message_addr_get_family(sd_rtnl_message *m, int *family) {
         struct ifaddrmsg *ifa;
 
         assert_return(m, -EINVAL);
@@ -352,7 +432,7 @@ int sd_rtnl_message_addr_get_ifindex(sd_rtnl_message *m, int *ifindex) {
 
 int sd_rtnl_message_new_addr(sd_rtnl *rtnl, sd_rtnl_message **ret,
                              uint16_t nlmsg_type, int index,
-                             unsigned char family) {
+                             int family) {
         struct ifaddrmsg *ifa;
         int r;
 
@@ -383,7 +463,7 @@ int sd_rtnl_message_new_addr(sd_rtnl *rtnl, sd_rtnl_message **ret,
 }
 
 int sd_rtnl_message_new_addr_update(sd_rtnl *rtnl, sd_rtnl_message **ret,
-                             int index, unsigned char family) {
+                             int index, int family) {
         int r;
 
         r = sd_rtnl_message_new_addr(rtnl, ret, RTM_NEWADDR, index, family);
@@ -464,6 +544,21 @@ int sd_rtnl_message_link_get_flags(sd_rtnl_message *m, unsigned *flags) {
         return 0;
 }
 
+int sd_rtnl_message_link_get_type(sd_rtnl_message *m, unsigned *type) {
+        struct ifinfomsg *ifi;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(rtnl_message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
+        assert_return(type, -EINVAL);
+
+        ifi = NLMSG_DATA(m->hdr);
+
+        *type = ifi->ifi_type;
+
+        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) {
@@ -515,7 +610,6 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data,
                 /* if no data was passed, make sure we still initialize the padding
                    note that we can have data_length > 0 (used by some containers) */
                 padding = RTA_DATA(rta);
-                data_length = 0;
         }
 
         /* make sure also the padding at the end of the message is initialized */
@@ -714,7 +808,7 @@ int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) {
         if (r < 0)
                 return r;
 
-        r = add_rtattr(m, type, NULL, size);
+        r = add_rtattr(m, type | NLA_F_NESTED, NULL, size);
         if (r < 0)
                 return r;
 
@@ -786,10 +880,12 @@ int rtnl_message_read_internal(sd_rtnl_message *m, unsigned short type, void **d
         return RTA_PAYLOAD(rta);
 }
 
-int sd_rtnl_message_read_string(sd_rtnl_message *m, unsigned short type, char **data) {
+int sd_rtnl_message_read_string(sd_rtnl_message *m, unsigned short type, const char **data) {
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_STRING);
         if (r < 0)
                 return r;
@@ -800,7 +896,8 @@ int sd_rtnl_message_read_string(sd_rtnl_message *m, unsigned short type, char **
         else if (strnlen(attr_data, r) >= (size_t) r)
                 return -EIO;
 
-        *data = (char *) attr_data;
+        if (data)
+                *data = (const char *) attr_data;
 
         return 0;
 }
@@ -809,6 +906,8 @@ int sd_rtnl_message_read_u8(sd_rtnl_message *m, unsigned short type, uint8_t *da
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_U8);
         if (r < 0)
                 return r;
@@ -819,7 +918,8 @@ int sd_rtnl_message_read_u8(sd_rtnl_message *m, unsigned short type, uint8_t *da
         else if ((size_t) r < sizeof(uint8_t))
                 return -EIO;
 
-        *data = *(uint8_t *) attr_data;
+        if (data)
+                *data = *(uint8_t *) attr_data;
 
         return 0;
 }
@@ -828,6 +928,8 @@ int sd_rtnl_message_read_u16(sd_rtnl_message *m, unsigned short type, uint16_t *
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_U16);
         if (r < 0)
                 return r;
@@ -838,7 +940,8 @@ int sd_rtnl_message_read_u16(sd_rtnl_message *m, unsigned short type, uint16_t *
         else if ((size_t) r < sizeof(uint16_t))
                 return -EIO;
 
-        *data = *(uint16_t *) attr_data;
+        if (data)
+                *data = *(uint16_t *) attr_data;
 
         return 0;
 }
@@ -847,6 +950,8 @@ int sd_rtnl_message_read_u32(sd_rtnl_message *m, unsigned short type, uint32_t *
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_U32);
         if (r < 0)
                 return r;
@@ -857,7 +962,8 @@ int sd_rtnl_message_read_u32(sd_rtnl_message *m, unsigned short type, uint32_t *
         else if ((size_t)r < sizeof(uint32_t))
                 return -EIO;
 
-        *data = *(uint32_t *) attr_data;
+        if (data)
+                *data = *(uint32_t *) attr_data;
 
         return 0;
 }
@@ -866,6 +972,8 @@ int sd_rtnl_message_read_ether_addr(sd_rtnl_message *m, unsigned short type, str
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_ETHER_ADDR);
         if (r < 0)
                 return r;
@@ -876,7 +984,8 @@ int sd_rtnl_message_read_ether_addr(sd_rtnl_message *m, unsigned short type, str
         else if ((size_t)r < sizeof(struct ether_addr))
                 return -EIO;
 
-        memcpy(data, attr_data, sizeof(struct ether_addr));
+        if (data)
+                memcpy(data, attr_data, sizeof(struct ether_addr));
 
         return 0;
 }
@@ -885,6 +994,8 @@ int sd_rtnl_message_read_cache_info(sd_rtnl_message *m, unsigned short type, str
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_CACHE_INFO);
         if (r < 0)
                 return r;
@@ -895,7 +1006,8 @@ int sd_rtnl_message_read_cache_info(sd_rtnl_message *m, unsigned short type, str
         else if ((size_t)r < sizeof(struct ifa_cacheinfo))
                 return -EIO;
 
-        memcpy(info, attr_data, sizeof(struct ifa_cacheinfo));
+        if (info)
+                memcpy(info, attr_data, sizeof(struct ifa_cacheinfo));
 
         return 0;
 }
@@ -904,6 +1016,8 @@ int sd_rtnl_message_read_in_addr(sd_rtnl_message *m, unsigned short type, struct
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_IN_ADDR);
         if (r < 0)
                 return r;
@@ -914,7 +1028,8 @@ int sd_rtnl_message_read_in_addr(sd_rtnl_message *m, unsigned short type, struct
         else if ((size_t)r < sizeof(struct in_addr))
                 return -EIO;
 
-        memcpy(data, attr_data, sizeof(struct in_addr));
+        if (data)
+                memcpy(data, attr_data, sizeof(struct in_addr));
 
         return 0;
 }
@@ -923,6 +1038,8 @@ int sd_rtnl_message_read_in6_addr(sd_rtnl_message *m, unsigned short type, struc
         int r;
         void *attr_data;
 
+        assert_return(m, -EINVAL);
+
         r = message_attribute_has_type(m, type, NLA_IN_ADDR);
         if (r < 0)
                 return r;
@@ -933,7 +1050,8 @@ int sd_rtnl_message_read_in6_addr(sd_rtnl_message *m, unsigned short type, struc
         else if ((size_t)r < sizeof(struct in6_addr))
                 return -EIO;
 
-        memcpy(data, attr_data, sizeof(struct in6_addr));
+        if (data)
+                memcpy(data, attr_data, sizeof(struct in6_addr));
 
         return 0;
 }
@@ -962,7 +1080,7 @@ int sd_rtnl_message_enter_container(sd_rtnl_message *m, unsigned short type) {
                         return r;
         } else if (nl_type->type == NLA_UNION) {
                 const NLTypeSystemUnion *type_system_union;
-                char *key;
+                const char *key;
 
                 r = type_system_get_type_system_union(m->container_type_system[m->n_containers],
                                                       &type_system_union,
@@ -1057,7 +1175,7 @@ int rtnl_message_parse(sd_rtnl_message *m,
         *rta_tb_size = max + 1;
 
         for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) {
-                type = rta->rta_type;
+                type = RTA_TYPE(rta);
 
                 /* if the kernel is newer than the headers we used
                    when building, we ignore out-of-range attributes
@@ -1098,6 +1216,63 @@ int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
         return k;
 }
 
+static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool peek) {
+        uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred)) +
+                            CMSG_SPACE(sizeof(struct nl_pktinfo))];
+        struct msghdr msg = {
+                .msg_iov = iov,
+                .msg_iovlen = 1,
+                .msg_control = cred_buffer,
+                .msg_controllen = sizeof(cred_buffer),
+        };
+        struct cmsghdr *cmsg;
+        uint32_t group = 0;
+        bool auth = false;
+        int r;
+
+        assert(fd >= 0);
+        assert(iov);
+
+        r = recvmsg(fd, &msg, MSG_TRUNC | (peek ? MSG_PEEK : 0));
+        if (r < 0) {
+                /* no data */
+                if (errno == ENOBUFS)
+                        log_debug("rtnl: kernel receive buffer overrun");
+
+                return (errno == EAGAIN) ? 0 : -errno;
+        } else if (r == 0)
+                /* connection was closed by the kernel */
+                return -ECONNRESET;
+
+        for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+                if (cmsg->cmsg_level == SOL_SOCKET &&
+                    cmsg->cmsg_type == SCM_CREDENTIALS &&
+                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
+                        struct ucred *ucred = (void *)CMSG_DATA(cmsg);
+
+                        /* from the kernel */
+                        if (ucred->uid == 0 && ucred->pid == 0)
+                                auth = true;
+                } else if (cmsg->cmsg_level == SOL_NETLINK &&
+                           cmsg->cmsg_type == NETLINK_PKTINFO &&
+                           cmsg->cmsg_len == CMSG_LEN(sizeof(struct nl_pktinfo))) {
+                        struct nl_pktinfo *pktinfo = (void *)CMSG_DATA(cmsg);
+
+                        /* multi-cast group */
+                        group = pktinfo->group;
+                }
+        }
+
+        if (!auth)
+                /* not from the kernel, ignore */
+                return 0;
+
+        if (group)
+                *_group = group;
+
+        return r;
+}
+
 /* 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.
@@ -1105,16 +1280,9 @@ int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m) {
  */
 int socket_read_message(sd_rtnl *rtnl) {
         _cleanup_rtnl_message_unref_ sd_rtnl_message *first = NULL;
-        uint8_t cred_buffer[CMSG_SPACE(sizeof(struct ucred))];
         struct iovec iov = {};
-        struct msghdr msg = {
-                .msg_iov = &iov,
-                .msg_iovlen = 1,
-                .msg_control = cred_buffer,
-                .msg_controllen = sizeof(cred_buffer),
-        };
-        struct cmsghdr *cmsg;
-        bool auth = false, multi_part = false, done = false;
+        uint32_t group = 0;
+        bool multi_part = false, done = false;
         struct nlmsghdr *new_msg;
         size_t len;
         int r;
@@ -1125,13 +1293,9 @@ int socket_read_message(sd_rtnl *rtnl) {
         assert(rtnl->rbuffer_allocated >= sizeof(struct nlmsghdr));
 
         /* read nothing, just get the pending message size */
-        r = recvmsg(rtnl->fd, &msg, MSG_PEEK | MSG_TRUNC);
-        if (r < 0)
-                /* no data */
-                return (errno == EAGAIN) ? 0 : -errno;
-        else if (r == 0)
-                /* connection was closed by the kernel */
-                return -ECONNRESET;
+        r = socket_recv_message(rtnl->fd, &iov, &group, true);
+        if (r <= 0)
+                return r;
         else
                 len = (size_t)r;
 
@@ -1144,13 +1308,10 @@ int socket_read_message(sd_rtnl *rtnl) {
         iov.iov_base = rtnl->rbuffer;
         iov.iov_len = rtnl->rbuffer_allocated;
 
-        r = recvmsg(rtnl->fd, &msg, MSG_TRUNC);
-        if (r < 0)
-                /* no data */
-                return (errno == EAGAIN) ? 0 : -errno;
-        else if (r == 0)
-                /* connection was closed by the kernel */
-                return -ECONNRESET;
+        /* read the pending message */
+        r = socket_recv_message(rtnl->fd, &iov, &group, false);
+        if (r <= 0)
+                return r;
         else
                 len = (size_t)r;
 
@@ -1158,24 +1319,6 @@ int socket_read_message(sd_rtnl *rtnl) {
                 /* message did not fit in read buffer */
                 return -EIO;
 
-        for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-                if (cmsg->cmsg_level == SOL_SOCKET &&
-                    cmsg->cmsg_type == SCM_CREDENTIALS &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
-                        struct ucred *ucred = (void *)CMSG_DATA(cmsg);
-
-                        /* from the kernel */
-                        if (ucred->uid == 0 && ucred->pid == 0) {
-                                auth = true;
-                                break;
-                        }
-                }
-        }
-
-        if (!auth)
-                /* not from the kernel, ignore */
-                return 0;
-
         if (NLMSG_OK(rtnl->rbuffer, len) && rtnl->rbuffer->nlmsg_flags & NLM_F_MULTI) {
                 multi_part = true;
 
@@ -1192,7 +1335,7 @@ int socket_read_message(sd_rtnl *rtnl) {
                 _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
                 const NLType *nl_type;
 
-                if (new_msg->nlmsg_pid && new_msg->nlmsg_pid != rtnl->sockaddr.nl.nl_pid)
+                if (!group && new_msg->nlmsg_pid != rtnl->sockaddr.nl.nl_pid)
                         /* not broadcast and not for us */
                         continue;
 
@@ -1217,8 +1360,10 @@ int socket_read_message(sd_rtnl *rtnl) {
                 }
 
                 /* check that the size matches the message type */
-                if (new_msg->nlmsg_len < NLMSG_LENGTH(nl_type->size))
+                if (new_msg->nlmsg_len < NLMSG_LENGTH(nl_type->size)) {
+                        log_debug("sd-rtnl: message larger than expected, dropping");
                         continue;
+                }
 
                 r = message_new_empty(rtnl, &m);
                 if (r < 0)