chiark / gitweb /
libsystemd-rtnl: add a rtnetlink library
authorTom Gundersen <teg@jklm.no>
Mon, 21 Oct 2013 18:12:52 +0000 (19:12 +0100)
committerTom Gundersen <teg@jklm.no>
Sun, 27 Oct 2013 21:18:34 +0000 (22:18 +0100)
This is intentionally as similar to sd-bus as possible. While it
would be simple to export it, the intentions is to keep this
internal (at least for the forseeable future).

Currently only synchronous communication is implemented

.gitignore
Makefile.am
src/libsystemd-rtnl/rtnl-internal.h [new file with mode: 0644]
src/libsystemd-rtnl/rtnl-message.c [new file with mode: 0644]
src/libsystemd-rtnl/sd-rtnl.c [new file with mode: 0644]
src/libsystemd-rtnl/test-rtnl.c [new file with mode: 0644]
src/systemd/sd-rtnl.h [new file with mode: 0644]

index d3cf8ef..dd6432c 100644 (file)
 /test-path-util
 /test-prioq
 /test-replace-var
+/test-rtnl
 /test-sched-prio
 /test-sleep
 /test-strip-tab-ansi
index e619100..6ce4b7f 100644 (file)
@@ -621,6 +621,25 @@ EXTRA_DIST += \
 
 # ------------------------------------------------------------------------------
 noinst_LTLIBRARIES += \
+       libsystemd-rtnl.la
+
+libsystemd_rtnl_la_SOURCES = \
+       src/systemd/sd-rtnl.h \
+       src/libsystemd-rtnl/sd-rtnl.c \
+       src/libsystemd-rtnl/rtnl-internal.h \
+       src/libsystemd-rtnl/rtnl-message.c
+
+test_rtnl_SOURCES = \
+       src/libsystemd-rtnl/test-rtnl.c
+
+test_rtnl_LDADD = \
+       libsystemd-shared.la \
+       libsystemd-rtnl.la
+
+tests += test-rtnl
+
+# ------------------------------------------------------------------------------
+noinst_LTLIBRARIES += \
        libsystemd-shared.la
 
 libsystemd_shared_la_SOURCES = \
diff --git a/src/libsystemd-rtnl/rtnl-internal.h b/src/libsystemd-rtnl/rtnl-internal.h
new file mode 100644 (file)
index 0000000..37b1d3d
--- /dev/null
@@ -0,0 +1,40 @@
+/*-*- 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 "refcnt.h"
+
+struct sd_rtnl {
+        RefCount n_ref;
+
+        int fd;
+
+        union {
+                struct sockaddr sa;
+                struct sockaddr_nl nl;
+        } sockaddr;
+
+        unsigned serial;
+};
+int message_get_errno(sd_rtnl_message *m);
+int message_get_serial(sd_rtnl_message *m);
+int message_seal(sd_rtnl *nl, sd_rtnl_message *m);
+int socket_write_message(sd_rtnl *nl, sd_rtnl_message *m);
+int socket_read_message(sd_rtnl *nl, sd_rtnl_message **ret);
diff --git a/src/libsystemd-rtnl/rtnl-message.c b/src/libsystemd-rtnl/rtnl-message.c
new file mode 100644 (file)
index 0000000..82ec1c9
--- /dev/null
@@ -0,0 +1,448 @@
+/*-*- 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 <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;
+
+        struct rtattr *next_rta;
+        size_t remaining_size;
+
+        bool sealed:1;
+};
+
+static int message_new(sd_rtnl_message **ret, size_t initial_size) {
+        sd_rtnl_message *m;
+
+        assert_return(ret, -EINVAL);
+        assert_return(initial_size > 0, -EINVAL);
+
+        m = new0(sd_rtnl_message, 1);
+        if (!m)
+                return -ENOMEM;
+
+        m->hdr = calloc(initial_size, 1);
+        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 sd_rtnl_message_link_new(__u16 nlmsg_type, int index, unsigned int type, unsigned int 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(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;
+
+        ifi = (struct ifinfomsg *) NLMSG_DATA((*ret)->hdr);
+
+        ifi->ifi_family = AF_UNSPEC;
+        ifi->ifi_index = index;
+        ifi->ifi_type = type;
+        ifi->ifi_flags = flags;
+        ifi->ifi_change = 0xffffffff;
+
+        return 0;
+}
+
+int sd_rtnl_message_addr_new(__u16 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(nlmsg_type == RTM_NEWADDR || nlmsg_type == RTM_DELADDR || nlmsg_type == RTM_GETADDR, -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 = (struct ifaddrmsg *) NLMSG_DATA((*ret)->hdr);
+
+        ifa->ifa_family = family;
+        ifa->ifa_prefixlen = prefixlen;
+        ifa->ifa_flags = flags;
+        ifa->ifa_scope = scope;
+        ifa->ifa_index = index;
+
+        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, __u16 *type) {
+        assert_return(m, -EINVAL);
+        assert_return(type, -EINVAL);
+
+        *type = m->hdr->nlmsg_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) {
+        __u32 rta_length, message_length;
+        struct nlmsghdr *new_hdr;
+        struct rtattr *rta;
+
+        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);
+
+        /* get the size of the new rta attribute (without 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)
+         */
+        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);
+        /* update message size */
+        m->hdr->nlmsg_len = message_length;
+
+        /* 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);
+
+        return 0;
+}
+
+int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void *data) {
+        __u16 rtm_type;
+        struct ifaddrmsg *ifa;
+
+        assert_return(m, -EINVAL);
+        assert_return(data, -EINVAL);
+
+        sd_rtnl_message_get_type(m, &rtm_type);
+
+        switch (rtm_type) {
+                case RTM_NEWLINK:
+                case RTM_DELLINK:
+                case RTM_GETLINK:
+                        switch (type) {
+                                case IFLA_IFNAME:
+                                case IFLA_QDISC:
+                                        return add_rtattr(m, type, data, strlen(data) + 1);
+                                case IFLA_MTU:
+                                        return add_rtattr(m, type, data, sizeof(unsigned int));
+                                case IFLA_LINK:
+                                        return add_rtattr(m, type, data, sizeof(int));
+                                case IFLA_STATS:
+                                        return add_rtattr(m, type, data, sizeof(struct rtnl_link_stats));
+                                case IFLA_ADDRESS:
+                                case IFLA_BROADCAST:
+                                        return add_rtattr(m, type, data, ETH_ALEN);
+                                default:
+                                        return -ENOTSUP;
+                        }
+                case RTM_NEWADDR:
+                case RTM_DELADDR:
+                case RTM_GETADDR:
+                        switch (type) {
+                                case IFA_LABEL:
+                                        return add_rtattr(m, type, data, strlen(data) + 1);
+                                case IFA_ADDRESS:
+                                case IFA_LOCAL:
+                                case IFA_BROADCAST:
+                                case IFA_ANYCAST:
+                                        ifa = NLMSG_DATA(m->hdr);
+                                        switch (ifa->ifa_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;
+                                        }
+                                default:
+                                        return -ENOTSUP;
+                        }
+                default:
+                        return -ENOTSUP;
+        }
+}
+
+static int message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
+        assert_return(m, -EINVAL);
+        assert_return(data, -EINVAL);
+
+        if (!RTA_OK(m->next_rta, m->remaining_size))
+                return 0;
+
+        *data = RTA_DATA(m->next_rta);
+        *type = m->next_rta->rta_type;
+
+        m->next_rta = RTA_NEXT(m->next_rta, m->remaining_size);
+
+        return 1;
+}
+
+int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data) {
+        __u16 rtm_type;
+
+        assert_return(m, -EINVAL);
+        assert_return(data, -EINVAL);
+
+        sd_rtnl_message_get_type(m, &rtm_type);
+
+        switch (rtm_type) {
+                case RTM_NEWLINK:
+                case RTM_DELLINK:
+                case RTM_GETLINK:
+                        if (!m->next_rta) {
+                                struct ifinfomsg *ifi = (struct ifinfomsg *) NLMSG_DATA(m->hdr);
+
+                                m->next_rta = IFLA_RTA(ifi);
+                                m->remaining_size = IFLA_PAYLOAD(m->hdr);
+                        }
+                        break;;
+                case RTM_NEWADDR:
+                case RTM_DELADDR:
+                case RTM_GETADDR:
+                        if (!m->next_rta) {
+                                struct ifaddrmsg *ifa = (struct ifaddrmsg *) NLMSG_DATA(m->hdr);
+
+                                m->next_rta = IFA_RTA(ifa);
+                                m->remaining_size = IFLA_PAYLOAD(m->hdr);
+                        }
+                        break;;
+                default:
+                        return -ENOTSUP;
+        }
+
+        return message_read(m, type, data);
+}
+
+int message_get_serial(sd_rtnl_message *m) {
+        assert(m);
+
+        return m->hdr->nlmsg_seq;
+}
+
+int message_get_errno(sd_rtnl_message *m) {
+        struct nlmsgerr *err;
+
+        assert(m);
+
+        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) {
+        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_return(rtnl, -EINVAL);
+        assert_return(need, -EINVAL);
+
+        /* 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 = getpagesize();
+        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) {
+        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));
+        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;
+        socklen_t addr_len = sizeof(nl->sockaddr);
+        int r;
+        ssize_t k;
+        size_t need;
+
+        assert_return(nl, -EINVAL);
+        assert_return(ret, -EINVAL);
+
+        r = message_receive_need(nl, &need);
+        if (r < 0)
+                return r;
+
+        r = message_new(&m, need);
+        if (r < 0)
+                return r;
+
+        r = message_receive_need(nl, &need);
+        if (r < 0)
+                return r;
+
+        m->hdr = realloc(m->hdr, need);
+        if (!m->hdr)
+                return -ENOMEM;
+
+        k = recvfrom(nl->fd, m->hdr, need,
+                        0, &nl->sockaddr.sa, &addr_len);
+        if (k < 0)
+                k = (errno == EAGAIN) ? 0 : -errno; /* no data? weird... */
+        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)
+                k = -EIO; /* not a netlink message */
+        else if (nl->sockaddr.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_type == NLMSG_NOOP)
+                k = 0;
+        else if (m->hdr->nlmsg_type == NLMSG_ERROR &&
+                 m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
+                k = -EIO;
+        else if ((pid_t) m->hdr->nlmsg_pid != getpid())
+                k = 0; /* not for us */
+
+        if (k > 0)
+                switch (m->hdr->nlmsg_type) {
+                        /* 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_DELLINK:
+                        case RTM_GETLINK:
+                                if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg)))
+                                        k = -EIO;
+                                break;;
+                        case RTM_NEWADDR:
+                        case RTM_DELADDR:
+                        case RTM_GETADDR:
+                                if (m->hdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifaddrmsg)))
+                                        k = -EIO;
+                                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;
+}
diff --git a/src/libsystemd-rtnl/sd-rtnl.c b/src/libsystemd-rtnl/sd-rtnl.c
new file mode 100644 (file)
index 0000000..abf45d0
--- /dev/null
@@ -0,0 +1,188 @@
+/*-*- 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 <sys/socket.h>
+#include <poll.h>
+
+#include "macro.h"
+#include "util.h"
+
+#include "sd-rtnl.h"
+#include "rtnl-internal.h"
+
+static int sd_rtnl_new(sd_rtnl **ret) {
+        sd_rtnl *rtnl;
+
+        assert_return(ret, -EINVAL);
+
+        rtnl = new0(sd_rtnl, 1);
+        if (!rtnl)
+                return -ENOMEM;
+
+        rtnl->n_ref = REFCNT_INIT;
+
+        rtnl->fd = -1;
+
+        rtnl->sockaddr.nl.nl_family = AF_NETLINK;
+
+        *ret = rtnl;
+        return 0;
+}
+
+int sd_rtnl_open(__u32 groups, sd_rtnl **ret) {
+        sd_rtnl *rtnl;
+        int r;
+
+        r = sd_rtnl_new(&rtnl);
+        if (r < 0)
+                return r;
+
+        rtnl->fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE);
+        if (rtnl->fd < 0) {
+                r = -errno;
+                sd_rtnl_unref(rtnl);
+                return r;
+        }
+
+        rtnl->sockaddr.nl.nl_groups = groups;
+
+        r = bind(rtnl->fd, &rtnl->sockaddr.sa, sizeof(rtnl->sockaddr));
+        if (r < 0) {
+                r = -errno;
+                sd_rtnl_unref(rtnl);
+                return r;
+        }
+
+        *ret = rtnl;
+
+        return 0;
+}
+
+sd_rtnl *sd_rtnl_ref(sd_rtnl *rtnl) {
+        if (rtnl)
+                assert_se(REFCNT_INC(rtnl->n_ref) >= 2);
+
+        return rtnl;
+}
+
+sd_rtnl *sd_rtnl_unref(sd_rtnl *rtnl) {
+        if (rtnl && REFCNT_DEC(rtnl->n_ref) <= 0) {
+                if (rtnl->fd >= 0)
+                        close_nointr_nofail(rtnl->fd);
+                free(rtnl);
+        }
+
+        return NULL;
+}
+
+int sd_rtnl_send_with_reply_and_block(sd_rtnl *nl,
+                                        sd_rtnl_message *message,
+                                        uint64_t usec,
+                                        sd_rtnl_message **ret) {
+        struct pollfd p[1] = {};
+        sd_rtnl_message *reply;
+        struct timespec left;
+        usec_t timeout;
+        int r, serial;
+
+        assert_return(nl, -EINVAL);
+        assert_return(message, -EINVAL);
+
+        r = message_seal(nl, message);
+        if (r < 0)
+                return r;
+
+        serial = message_get_serial(message);
+
+        p[0].fd = nl->fd;
+        p[0].events = POLLOUT;
+
+        timeout = now(CLOCK_MONOTONIC) + usec;
+
+        for (;;) {
+                if (usec != (uint64_t) -1) {
+                        usec_t n;
+
+                        n = now(CLOCK_MONOTONIC);
+                        if (n >= timeout)
+                                return -ETIMEDOUT;
+
+                        timespec_store(&left, timeout - n);
+                }
+
+                r = ppoll(p, 1, usec == (uint64_t) -1 ? NULL : &left, NULL);
+                if (r < 0)
+                        return 0;
+
+                r = socket_write_message(nl, message);
+                if (r < 0)
+                        return r;
+
+                if (r > 0) {
+                        break;
+                }
+        }
+
+        p[0].events = POLLIN;
+
+        for (;;) {
+                if (usec != (uint64_t) -1) {
+                        usec_t n;
+
+                        n = now(CLOCK_MONOTONIC);
+                        if (n >= timeout)
+                                return -ETIMEDOUT;
+
+                        timespec_store(&left, timeout - n);
+                }
+
+                r = ppoll(p, 1, usec == (uint64_t) -1 ? NULL : &left, NULL);
+                if (r < 0)
+                        return r;
+
+                r = socket_read_message(nl, &reply);
+                if (r < 0)
+                        return r;
+
+                if (r > 0) {
+                        int received_serial = message_get_serial(reply);
+
+                        if (received_serial == serial) {
+                                r = message_get_errno(reply);
+                                if (r < 0) {
+                                        sd_rtnl_message_unref(reply);
+                                        return r;
+                                }
+
+                                if (ret)
+                                        *ret = reply;
+                                else
+                                        reply = sd_rtnl_message_unref(reply);
+
+                                break;;
+                        }
+
+                        reply = sd_rtnl_message_unref(reply);
+                }
+        }
+
+        return 0;
+}
diff --git a/src/libsystemd-rtnl/test-rtnl.c b/src/libsystemd-rtnl/test-rtnl.c
new file mode 100644 (file)
index 0000000..bcfd816
--- /dev/null
@@ -0,0 +1,126 @@
+/*-*- 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 <netinet/ether.h>
+
+#include "util.h"
+#include "macro.h"
+#include "sd-rtnl.h"
+#include "socket-util.h"
+
+static void test_link_configure(sd_rtnl *rtnl, int ifindex) {
+        _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *message;
+        __u16 type;
+        const char *mac = "98:fe:94:3f:c6:18", *name = "test";
+        unsigned int mtu = 1450;
+        void *data;
+
+        /* we'd really like to test NEWLINK, but let's not mess with the running kernel */
+        assert(sd_rtnl_message_link_new(RTM_GETLINK, ifindex, 0, 0, &message) >= 0);
+        assert(sd_rtnl_message_append(message, IFLA_IFNAME, name) >= 0);
+        assert(sd_rtnl_message_append(message, IFLA_ADDRESS, ether_aton(mac)) >= 0);
+        assert(sd_rtnl_message_append(message, IFLA_MTU, &mtu) >= 0);
+
+        assert(sd_rtnl_message_read(message, &type, &data) >= 0);
+        assert(type == IFLA_IFNAME);
+        assert(streq(name, (char *) data));
+
+        assert(sd_rtnl_message_read(message, &type, &data) >= 0);
+        assert(type == IFLA_ADDRESS);
+        assert(streq(mac, ether_ntoa(data)));
+
+        assert(sd_rtnl_message_read(message, &type, &data) >= 0);
+        assert(type == IFLA_MTU);
+        assert(mtu == *(unsigned int *) data);
+
+        /* let's assume that this test is always ran when the loopback device is up, so that it will fail */
+        assert(sd_rtnl_send_with_reply_and_block(rtnl, message, 2 * USEC_PER_SEC, NULL) == 0);
+}
+
+int main(void) {
+        sd_rtnl *rtnl;
+        sd_rtnl_message *m;
+        sd_rtnl_message *r;
+        void *data;
+        int if_loopback;
+        __u16 type;
+        unsigned int mtu = 0;
+        unsigned int *mtu_reply;
+
+        assert(sd_rtnl_open(0, &rtnl) >= 0);
+        assert(rtnl);
+
+        if_loopback = (int) if_nametoindex("lo");
+        assert(if_loopback > 0);
+
+        test_link_configure(rtnl, if_loopback);
+
+        assert(sd_rtnl_message_link_new(RTM_GETLINK, if_loopback, 0, 0, &m) >= 0);
+        assert(m);
+
+        assert(sd_rtnl_message_get_type(m, &type) >= 0);
+        assert(type == RTM_GETLINK);
+
+        assert(sd_rtnl_message_read(m, &type, &data) == 0);
+
+        assert(sd_rtnl_send_with_reply_and_block(rtnl, m, 100000000, &r) >= 0);
+        assert(sd_rtnl_message_get_type(r, &type) >= 0);
+        assert(type == RTM_NEWLINK);
+
+        assert(sd_rtnl_message_read(m, &type, data) == 0);
+        assert((r = sd_rtnl_message_unref(r)) == NULL);
+
+        assert(sd_rtnl_send_with_reply_and_block(rtnl, m, -1, &r) == -EPERM);
+        assert((m = sd_rtnl_message_unref(m)) == NULL);
+        assert((r = sd_rtnl_message_unref(r)) == NULL);
+
+        assert(sd_rtnl_message_link_new(RTM_GETLINK, if_loopback, 0, 0, &m) >= 0);
+        assert(m);
+
+        assert(sd_rtnl_message_append(m, IFLA_MTU, &mtu) >= 0);
+        assert(sd_rtnl_message_read(m, &type, (void **) &mtu_reply) == 1);
+
+        assert(type == IFLA_MTU);
+        assert(*mtu_reply == 0);
+
+        assert(sd_rtnl_message_read(m, &type, data) == 0);
+
+        assert(sd_rtnl_send_with_reply_and_block(rtnl, m, -1, &r) >= 0);
+        while (sd_rtnl_message_read(r, &type, &data)) {
+                switch (type) {
+                        case IFLA_MTU:
+                                assert(*(unsigned int *) data == 65536);
+                                break;;
+                        case IFLA_IFNAME:
+                                assert(streq((char *) data, "lo"));
+                                break;;
+                        case IFLA_QDISC:
+                                assert(streq((char *) data, "noqueue"));
+                                break;;
+                }
+        }
+
+        assert((m = sd_rtnl_message_unref(m)) == NULL);
+        assert((r = sd_rtnl_message_unref(r)) == NULL);
+        assert((rtnl = sd_rtnl_unref(rtnl)) == NULL);
+
+        return EXIT_SUCCESS;
+}
diff --git a/src/systemd/sd-rtnl.h b/src/systemd/sd-rtnl.h
new file mode 100644 (file)
index 0000000..5f5f3e3
--- /dev/null
@@ -0,0 +1,52 @@
+/*-*- 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 <linux/netlink.h>
+#include <stdint.h>
+#include <util.h>
+
+typedef struct sd_rtnl sd_rtnl;
+typedef struct sd_rtnl_message sd_rtnl_message;
+
+/* bus */
+int sd_rtnl_open(__u32 groups, sd_rtnl **nl);
+
+sd_rtnl *sd_rtnl_ref(sd_rtnl *nl);
+sd_rtnl *sd_rtnl_unref(sd_rtnl *nl);
+
+int sd_rtnl_send_with_reply_and_block(sd_rtnl *nl, sd_rtnl_message *message, uint64_t timeout, sd_rtnl_message **reply);
+
+/* messages */
+int sd_rtnl_message_link_new(__u16 msg_type, int index, unsigned int type, unsigned int flags, sd_rtnl_message **ret);
+int sd_rtnl_message_addr_new(__u16 msg_type, int index, unsigned char family, unsigned char prefixlen, unsigned char flags, unsigned char scope, sd_rtnl_message **ret);
+sd_rtnl_message *sd_rtnl_message_ref(sd_rtnl_message *m);
+sd_rtnl_message *sd_rtnl_message_unref(sd_rtnl_message *m);
+
+int sd_rtnl_message_get_type(sd_rtnl_message *m, __u16 *type);
+int sd_rtnl_message_append(sd_rtnl_message *m, unsigned short type, const void *data);
+int sd_rtnl_message_read(sd_rtnl_message *m, unsigned short *type, void **data);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(sd_rtnl*, sd_rtnl_unref);
+DEFINE_TRIVIAL_CLEANUP_FUNC(sd_rtnl_message*, sd_rtnl_message_unref);
+
+#define _cleanup_sd_rtnl_unref_ _cleanup_(sd_rtnl_unrefp)
+#define _cleanup_sd_rtnl_message_unref_ _cleanup_(sd_rtnl_message_unrefp)