sd-radv: Add Router Advertisement prefix handling

Define Router Advertisement prefix structure. Add the Prefix
Information ICMPv6 option defined in RFC 4861 to the prefix
information structure, as it will simplify sending a Prefix
Information option later on. In order to handle endianness
correctly, the structure is redefined here instead of using
the one in netinet/icmp6.h.

Add functions to create and modify prefix information and set
default values as defined in RFC 4861, Section 6.2.1.

4 files changed, 243 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index b62166cd16..29fa71df0d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3637,6 +3637,7 @@ libsystemd_network_la_SOURCES = \
 	src/systemd/sd-ipv4ll.h \
 	src/systemd/sd-ipv4acd.h \
 	src/systemd/sd-ndisc.h \
+	src/systemd/sd-radv.h \
 	src/systemd/sd-dhcp6-client.h \
 	src/systemd/sd-dhcp6-lease.h \
 	src/systemd/sd-lldp.h \
@@ -3660,6 +3661,8 @@ libsystemd_network_la_SOURCES = \
 	src/libsystemd-network/ndisc-internal.h \
 	src/libsystemd-network/ndisc-router.h \
 	src/libsystemd-network/ndisc-router.c \
+	src/libsystemd-network/sd-radv.c \
+	src/libsystemd-network/radv-internal.h \
 	src/libsystemd-network/icmp6-util.h \
 	src/libsystemd-network/icmp6-util.c \
 	src/libsystemd-network/sd-dhcp6-client.c \
diff --git a/src/libsystemd-network/radv-internal.h b/src/libsystemd-network/radv-internal.h
new file mode 100644
index 0000000000..0f92c8b55c
--- /dev/null
+++ b/src/libsystemd-network/radv-internal.h
@@ -0,0 +1,48 @@
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2017 Intel Corporation. All rights reserved.
+
+  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 "sd-radv.h"
+
+#include "log.h"
+#include "list.h"
+#include "sparse-endian.h"
+
+struct sd_radv_prefix {
+        unsigned n_ref;
+
+        struct {
+                uint8_t type;
+                uint8_t length;
+                uint8_t prefixlen;
+                uint8_t flags;
+                be32_t valid_lifetime;
+                be32_t preferred_lifetime;
+                uint32_t reserved;
+                struct in6_addr in6_addr;
+        } _packed_ opt;
+
+        LIST_FIELDS(struct sd_radv_prefix, prefix);
+};
+
+#define log_radv_full(level, error, fmt, ...) log_internal(level, error, __FILE__, __LINE__, __func__, "RADV: " fmt, ##__VA_ARGS__)
+#define log_radv_errno(error, fmt, ...) log_radv_full(LOG_DEBUG, error, fmt, ##__VA_ARGS__)
+#define log_radv_warning_errno(error, fmt, ...) log_radv_full(LOG_WARNING, error, fmt, ##__VA_ARGS__)
+#define log_radv(fmt, ...) log_radv_errno(0, fmt, ##__VA_ARGS__)
diff --git a/src/libsystemd-network/sd-radv.c b/src/libsystemd-network/sd-radv.c
new file mode 100644
index 0000000000..54f126e0f6
--- /dev/null
+++ b/src/libsystemd-network/sd-radv.c
@@ -0,0 +1,136 @@
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2017 Intel Corporation. All rights reserved.
+
+  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/icmp6.h>
+#include <netinet/in.h>
+
+#include "sd-radv.h"
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "icmp6-util.h"
+#include "in-addr-util.h"
+#include "radv-internal.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "util.h"
+
+_public_ int sd_radv_prefix_new(sd_radv_prefix **ret) {
+        _cleanup_(sd_radv_prefix_unrefp) sd_radv_prefix *p = NULL;
+
+        assert_return(ret, -EINVAL);
+
+        p = new0(sd_radv_prefix, 1);
+        if (!p)
+                return -ENOMEM;
+
+        p->n_ref = 1;
+
+        p->opt.type = ND_OPT_PREFIX_INFORMATION;
+        p->opt.length = (sizeof(p->opt) - 1) /8 + 1;
+
+        p->opt.prefixlen = 64;
+
+        /* RFC 4861, Section 6.2.1 */
+        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, true);
+        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, true);
+        p->opt.preferred_lifetime = htobe32(604800);
+        p->opt.valid_lifetime = htobe32(2592000);
+
+        *ret = p;
+        p = NULL;
+
+        return 0;
+}
+
+_public_ sd_radv_prefix *sd_radv_prefix_ref(sd_radv_prefix *p) {
+        if (!p)
+                return NULL;
+
+        assert(p->n_ref > 0);
+        p->n_ref++;
+
+        return p;
+}
+
+_public_ sd_radv_prefix *sd_radv_prefix_unref(sd_radv_prefix *p) {
+        if (!p)
+                return NULL;
+
+        assert(p->n_ref > 0);
+        p->n_ref--;
+
+        if (p->n_ref > 0)
+                return NULL;
+
+        return mfree(p);
+}
+
+_public_ int sd_radv_prefix_set_prefix(sd_radv_prefix *p, struct in6_addr *in6_addr,
+                                       unsigned char prefixlen) {
+        assert_return(p, -EINVAL);
+        assert_return(in6_addr, -EINVAL);
+
+        if (prefixlen < 3 || prefixlen > 128)
+                return -EINVAL;
+
+        if (prefixlen > 64)
+                /* unusual but allowed, log it */
+                log_radv("Unusual prefix length %d greater than 64", prefixlen);
+
+        p->opt.in6_addr = *in6_addr;
+        p->opt.prefixlen = prefixlen;
+
+        return 0;
+}
+
+_public_ int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink) {
+        assert_return(p, -EINVAL);
+
+        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_ONLINK, onlink);
+
+        return 0;
+}
+
+_public_ int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
+                                                          int address_autoconfiguration) {
+        assert_return(p, -EINVAL);
+
+        SET_FLAG(p->opt.flags, ND_OPT_PI_FLAG_AUTO, address_autoconfiguration);
+
+        return 0;
+}
+
+_public_ int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
+                                               uint32_t valid_lifetime) {
+        assert_return(p, -EINVAL);
+
+        p->opt.valid_lifetime = htobe32(valid_lifetime);
+
+        return 0;
+}
+
+_public_ int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
+                                                   uint32_t preferred_lifetime) {
+        assert_return(p, -EINVAL);
+
+        p->opt.preferred_lifetime = htobe32(preferred_lifetime);
+
+        return 0;
+}
diff --git a/src/systemd/sd-radv.h b/src/systemd/sd-radv.h
new file mode 100644
index 0000000000..c9933674bd
--- /dev/null
+++ b/src/systemd/sd-radv.h
@@ -0,0 +1,56 @@
+#ifndef foosdradvfoo
+#define foosdradvfoo
+
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2017 Intel Corporation. All rights reserved.
+
+  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 <inttypes.h>
+#include <net/ethernet.h>
+#include <netinet/in.h>
+#include <sys/types.h>
+
+#include "sd-event.h"
+
+#include "_sd-common.h"
+
+_SD_BEGIN_DECLARATIONS;
+
+typedef struct sd_radv_prefix sd_radv_prefix;
+
+/* Advertised prefixes */
+int sd_radv_prefix_new(sd_radv_prefix **ret);
+sd_radv_prefix *sd_radv_prefix_ref(sd_radv_prefix *ra);
+sd_radv_prefix *sd_radv_prefix_unref(sd_radv_prefix *ra);
+
+int sd_radv_prefix_set_prefix(sd_radv_prefix *p, struct in6_addr *in6_addr,
+                              unsigned char prefixlen);
+int sd_radv_prefix_set_onlink(sd_radv_prefix *p, int onlink);
+int sd_radv_prefix_set_address_autoconfiguration(sd_radv_prefix *p,
+                                                 int address_autoconfiguration);
+int sd_radv_prefix_set_valid_lifetime(sd_radv_prefix *p,
+                                      uint32_t valid_lifetime);
+int sd_radv_prefix_set_preferred_lifetime(sd_radv_prefix *p,
+                                          uint32_t preferred_lifetime);
+
+_SD_DEFINE_POINTER_CLEANUP_FUNC(sd_radv, sd_radv_unref);
+_SD_DEFINE_POINTER_CLEANUP_FUNC(sd_radv_prefix, sd_radv_prefix_unref);
+
+_SD_END_DECLARATIONS;
+
+#endif