chiark / gitweb /
sd-dhcp-client/net-util: make netmask_to_prefixlen generic
[elogind.git] / src / libsystemd / sd-rtnl / rtnl-message.c
index 984115c3c0fc6413274f20938ebe7a286f53fb3e..85c59bfed12ca1644b8be055aaa4dbba32105c60 100644 (file)
@@ -35,15 +35,17 @@ struct sd_rtnl_message {
         RefCount n_ref;
 
         struct nlmsghdr *hdr;
-        size_t container_offset; /* offset from hdr to container start */
+        size_t container_offsets[RTNL_CONTAINER_DEPTH]; /* offset from hdr to each container's start */
+        unsigned n_containers; /* number of containers */
         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 GET_CONTAINER(m, i) (i < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offsets[i]) : 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;
+#define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr;
 
 static int message_new(sd_rtnl_message **ret, size_t initial_size) {
         sd_rtnl_message *m;
@@ -129,8 +131,16 @@ bool message_type_is_addr(uint16_t type) {
 int sd_rtnl_message_route_set_dst_prefixlen(sd_rtnl_message *m, unsigned char prefixlen) {
         struct rtmsg *rtm;
 
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(message_type_is_route(m->hdr->nlmsg_type), -EINVAL);
+
         rtm = NLMSG_DATA(m->hdr);
 
+        if ((rtm->rtm_family == AF_INET && prefixlen > 32) ||
+            (rtm->rtm_family == AF_INET6 && prefixlen > 128))
+                return -ERANGE;
+
         rtm->rtm_dst_len = prefixlen;
 
         return 0;
@@ -167,13 +177,20 @@ int sd_rtnl_message_route_new(uint16_t nlmsg_type, unsigned char rtm_family,
         return 0;
 }
 
-int sd_rtnl_message_link_set_flags(sd_rtnl_message *m, unsigned flags) {
+int sd_rtnl_message_link_set_flags(sd_rtnl_message *m, unsigned flags, unsigned change) {
         struct ifinfomsg *ifi;
 
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
+
         ifi = NLMSG_DATA(m->hdr);
 
         ifi->ifi_flags = flags;
-        ifi->ifi_change = 0xffffffff;
+        if (change)
+                ifi->ifi_change = change;
+        else
+                ifi->ifi_change = 0xffffffff;
 
         return 0;
 }
@@ -181,6 +198,10 @@ int sd_rtnl_message_link_set_flags(sd_rtnl_message *m, unsigned flags) {
 int sd_rtnl_message_link_set_type(sd_rtnl_message *m, unsigned type) {
         struct ifinfomsg *ifi;
 
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(message_type_is_link(m->hdr->nlmsg_type), -EINVAL);
+
         ifi = NLMSG_DATA(m->hdr);
 
         ifi->ifi_type = type;
@@ -215,12 +236,60 @@ int sd_rtnl_message_link_new(uint16_t nlmsg_type, int index, sd_rtnl_message **r
         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) {
+int sd_rtnl_message_addr_set_prefixlen(sd_rtnl_message *m, unsigned char prefixlen) {
+        struct ifaddrmsg *ifa;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(message_type_is_addr(m->hdr->nlmsg_type), -EINVAL);
+
+        ifa = NLMSG_DATA(m->hdr);
+
+        if ((ifa->ifa_family == AF_INET && prefixlen > 32) ||
+            (ifa->ifa_family == AF_INET6 && prefixlen > 128))
+                return -ERANGE;
+
+        ifa->ifa_prefixlen = prefixlen;
+
+        return 0;
+}
+
+int sd_rtnl_message_addr_set_flags(sd_rtnl_message *m, unsigned char flags) {
+        struct ifaddrmsg *ifa;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(message_type_is_addr(m->hdr->nlmsg_type), -EINVAL);
+
+        ifa = NLMSG_DATA(m->hdr);
+
+        ifa->ifa_flags = flags;
+
+        return 0;
+}
+
+int sd_rtnl_message_addr_set_scope(sd_rtnl_message *m, unsigned char scope) {
+        struct ifaddrmsg *ifa;
+
+        assert_return(m, -EINVAL);
+        assert_return(m->hdr, -EINVAL);
+        assert_return(message_type_is_addr(m->hdr->nlmsg_type), -EINVAL);
+
+        ifa = NLMSG_DATA(m->hdr);
+
+        ifa->ifa_scope = scope;
+
+        return 0;
+}
+
+int sd_rtnl_message_addr_new(uint16_t nlmsg_type, int index, unsigned char family,
+                             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(family == AF_INET || family == AF_INET6, -EINVAL);
         assert_return(ret, -EINVAL);
 
         r = message_new(ret, NLMSG_SPACE(sizeof(struct ifaddrmsg)));
@@ -232,11 +301,12 @@ int sd_rtnl_message_addr_new(uint16_t nlmsg_type, int index, unsigned char famil
 
         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;
+        ifa->ifa_family = family;
+        if (family == AF_INET)
+                ifa->ifa_prefixlen = 32;
+        else if (family == AF_INET6)
+                ifa->ifa_prefixlen = 128;
 
         UPDATE_RTA(*ret, IFA_RTA(ifa));
 
@@ -305,11 +375,14 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data,
         struct nlmsghdr *new_hdr;
         struct rtattr *rta;
         char *padding;
+        unsigned i;
 
         assert(m);
         assert(m->hdr);
+        assert(!m->sealed);
         assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
         assert(!data || data_length > 0);
+        assert(data || m->n_containers < RTNL_CONTAINER_DEPTH);
 
         /* get the size of the new rta attribute (with padding at the end) */
         rta_length = RTA_LENGTH(data_length);
@@ -326,16 +399,16 @@ static int add_rtattr(sd_rtnl_message *m, unsigned short type, const void *data,
         /* 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;
+        /* if we are inside containers, extend them */
+        for (i = 0; i < m->n_containers; i++)
+                GET_CONTAINER(m, i)->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;
+                m->container_offsets[m->n_containers ++] = 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)
@@ -357,6 +430,7 @@ int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const
         int r;
 
         assert_return(m, -EINVAL);
+        assert_return(!m->sealed, -EPERM);
         assert_return(data, -EINVAL);
 
         r = sd_rtnl_message_get_type(m, &rtm_type);
@@ -369,8 +443,8 @@ int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const
                 case RTM_SETLINK:
                 case RTM_GETLINK:
                 case RTM_DELLINK:
-                        if (CURRENT_CONTAINER(m)) {
-                                if (CURRENT_CONTAINER(m)->rta_type != IFLA_LINKINFO ||
+                        if (m->n_containers == 1) {
+                                if (GET_CONTAINER(m, 0)->rta_type != IFLA_LINKINFO ||
                                     type != IFLA_INFO_KIND)
                                         return -ENOTSUP;
                         } else {
@@ -401,11 +475,48 @@ int sd_rtnl_message_append_string(sd_rtnl_message *m, unsigned short type, const
         return 0;
 }
 
+int sd_rtnl_message_append_u16(sd_rtnl_message *m, unsigned short type, uint16_t data) {
+        uint16_t rtm_type;
+        int r;
+
+        assert_return(m, -EINVAL);
+        assert_return(!m->sealed, -EPERM);
+
+        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 (m->n_containers == 2 &&
+                            GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO &&
+                            GET_CONTAINER(m, 1)->rta_type == IFLA_INFO_DATA &&
+                            type == IFLA_VLAN_ID)
+                                break;
+                        else
+                                return -ENOTSUP;
+                        break;
+                default:
+                        return -ENOTSUP;
+        }
+
+        r = add_rtattr(m, type, &data, sizeof(uint16_t));
+        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);
+        assert_return(!m->sealed, -EPERM);
 
         r = sd_rtnl_message_get_type(m, &rtm_type);
         if (r < 0)
@@ -457,6 +568,7 @@ int sd_rtnl_message_append_in_addr(sd_rtnl_message *m, unsigned short type, cons
         int r;
 
         assert_return(m, -EINVAL);
+        assert_return(!m->sealed, -EPERM);
         assert_return(data, -EINVAL);
 
         r = sd_rtnl_message_get_type(m, &rtm_type);
@@ -518,6 +630,7 @@ int sd_rtnl_message_append_in6_addr(sd_rtnl_message *m, unsigned short type, con
         int r;
 
         assert_return(m, -EINVAL);
+        assert_return(!m->sealed, -EPERM);
         assert_return(data, -EINVAL);
 
         r = sd_rtnl_message_get_type(m, &rtm_type);
@@ -576,6 +689,7 @@ int sd_rtnl_message_append_ether_addr(sd_rtnl_message *m, unsigned short type, c
         int r;
 
         assert_return(m, -EINVAL);
+        assert_return(!m->sealed, -EPERM);
         assert_return(data, -EINVAL);
 
         sd_rtnl_message_get_type(m, &rtm_type);
@@ -608,12 +722,14 @@ 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);
+        assert_return(!m->sealed, -EPERM);
 
         sd_rtnl_message_get_type(m, &rtm_type);
 
         if (message_type_is_link(rtm_type)) {
-                if (type == IFLA_LINKINFO)
+                if ((type == IFLA_LINKINFO && m->n_containers == 0) ||
+                    (type == IFLA_INFO_DATA && m->n_containers == 1 &&
+                     GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO))
                         return add_rtattr(m, type, NULL, 0);
                 else
                         return -ENOTSUP;
@@ -625,9 +741,10 @@ int sd_rtnl_message_open_container(sd_rtnl_message *m, unsigned short type) {
 
 int sd_rtnl_message_close_container(sd_rtnl_message *m) {
         assert_return(m, -EINVAL);
-        assert_return(CURRENT_CONTAINER(m), -EINVAL);
+        assert_return(!m->sealed, -EPERM);
+        assert_return(m->n_containers > 0, -EINVAL);
 
-        m->container_offset = 0;
+        m->n_containers --;
 
         return 0;
 }
@@ -637,34 +754,57 @@ int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data)
         uint16_t rtm_type;
         int r;
 
-        assert(m);
-        assert(m->next_rta_offset);
-        assert(type);
-        assert(data);
+        assert_return(m, -EINVAL);
+        assert_return(m->sealed, -EPERM);
+        assert_return(m->next_rta_offset, -EINVAL);
+        assert_return(type, -EINVAL);
+        assert_return(data, -EINVAL);
 
-        remaining_size = m->hdr->nlmsg_len - m->next_rta_offset;
+        /* only read until the end of the current container */
+        if (m->n_containers)
+                remaining_size = GET_CONTAINER(m, m->n_containers - 1)->rta_len -
+                                 (m->next_rta_offset -
+                                  m->container_offsets[m->n_containers - 1]);
+        else
+                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 */
+        /* if we read a container, enter it and return its type */
         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));
+        if (message_type_is_link(rtm_type) &&
+            ((m->n_containers == 0 &&
+              NEXT_RTA(m)->rta_type == IFLA_LINKINFO) ||
+             (m->n_containers == 1 &&
+              GET_CONTAINER(m, 0)->rta_type == IFLA_LINKINFO &&
+              NEXT_RTA(m)->rta_type == IFLA_INFO_DATA))) {
+                *data = NULL;
+                PUSH_CONTAINER(m, NEXT_RTA(m));
+                UPDATE_RTA(m, RTA_DATA(NEXT_RTA(m)));
+        } else {
+                *data = RTA_DATA(NEXT_RTA(m));
+                UPDATE_RTA(m, RTA_NEXT(NEXT_RTA(m), remaining_size));
+        }
 
         return 1;
 }
 
+int sd_rtnl_message_exit_container(sd_rtnl_message *m) {
+        assert_return(m, -EINVAL);
+        assert_return(m->sealed, -EINVAL);
+        assert_return(m->n_containers > 0, -EINVAL);
+
+        m->n_containers --;
+
+        return 0;
+}
+
 uint32_t message_get_serial(sd_rtnl_message *m) {
         assert(m);
         assert(m->hdr);
@@ -687,16 +827,23 @@ int sd_rtnl_message_get_errno(sd_rtnl_message *m) {
 }
 
 int message_seal(sd_rtnl *nl, sd_rtnl_message *m) {
-        assert(nl);
+        int r;
+
         assert(m);
         assert(m->hdr);
 
         if (m->sealed)
                 return -EPERM;
 
-        m->hdr->nlmsg_seq = nl->serial++;
+        if (nl)
+                m->hdr->nlmsg_seq = nl->serial++;
+
         m->sealed = true;
 
+        r = sd_rtnl_message_rewind(m);
+        if (r < 0)
+                return r;
+
         return 0;
 }
 
@@ -769,6 +916,9 @@ int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret) {
         if (r < 0)
                 return r;
 
+        /* don't allow sealing/appending to received messages */
+        m->sealed = true;
+
         addr_len = sizeof(addr);
 
         k = recvfrom(nl->fd, m->hdr, need,
@@ -854,6 +1004,7 @@ int sd_rtnl_message_rewind(sd_rtnl_message *m) {
         struct rtmsg *rtm;
 
         assert_return(m, -EINVAL);
+        assert_return(m->sealed, -EPERM);
         assert_return(m->hdr, -EINVAL);
 
         switch(m->hdr->nlmsg_type) {
@@ -883,5 +1034,7 @@ int sd_rtnl_message_rewind(sd_rtnl_message *m) {
                         return -ENOTSUP;
         }
 
+        m->n_containers = 0;
+
         return 0;
 }