sd-rtnl: rework rtnl type system

Use a static table with all the typing information, rather than repeated
switch statements. This should make it a lot simpler to add new types.

We need to keep all the type info to be able to create containers
without exposing their implementation details to the users of the library.

As a freebee we verify the types of appended/read attributes.

The API is extended to nicely deal with unions of container types.

1 files changed, 356 insertions, 0 deletions

diff --git a/src/libsystemd/sd-rtnl/rtnl-types.c b/src/libsystemd/sd-rtnl/rtnl-types.c
new file mode 100644
index 0000000000..936073e49c
--- /dev/null
+++ b/src/libsystemd/sd-rtnl/rtnl-types.c
@@ -0,0 +1,356 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 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 <stddef.h>
+#include <stdint.h>
+#include <sys/socket.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/in6.h>
+#include <linux/veth.h>
+#include <linux/if_bridge.h>
+#include <linux/if_addr.h>
+#include <linux/if.h>
+
+#include "macro.h"
+#include "util.h"
+
+#include "rtnl-types.h"
+
+static const NLTypeSystem rtnl_link_type_system;
+
+static const NLType rtnl_link_info_data_veth_types[VETH_INFO_MAX + 1] = {
+        [VETH_INFO_PEER]  = { .type = NLA_NESTED, .type_system = &rtnl_link_type_system, .size = sizeof(struct ifinfomsg) },
+};
+
+
+static const NLType rtnl_link_info_data_macvlan_types[IFLA_MACVLAN_MAX + 1] = {
+        [IFLA_MACVLAN_MODE]  = { .type = NLA_U32 },
+        [IFLA_MACVLAN_FLAGS] = { .type = NLA_U16 },
+};
+
+static const NLType rtnl_link_info_data_bridge_types[IFLA_BRIDGE_MAX + 1] = {
+        [IFLA_BRIDGE_FLAGS]     = { .type = NLA_U16 },
+        [IFLA_BRIDGE_MODE]      = { .type = NLA_U16 },
+/*
+        [IFLA_BRIDGE_VLAN_INFO] = { .type = NLA_BINARY,
+                                    .len = sizeof(struct bridge_vlan_info), },
+*/
+};
+
+static const NLType rtnl_link_info_data_vlan_types[IFLA_VLAN_MAX + 1] = {
+        [IFLA_VLAN_ID]          = { .type = NLA_U16 },
+/*
+        [IFLA_VLAN_FLAGS]       = { .len = sizeof(struct ifla_vlan_flags) },
+        [IFLA_VLAN_EGRESS_QOS]  = { .type = NLA_NESTED },
+        [IFLA_VLAN_INGRESS_QOS] = { .type = NLA_NESTED },
+*/
+        [IFLA_VLAN_PROTOCOL]    = { .type = NLA_U16 },
+};
+
+static const NLType rtnl_link_info_data_bond_types[IFLA_BOND_MAX + 1] = {
+        [IFLA_BOND_MODE]                = { .type = NLA_U8 },
+        [IFLA_BOND_ACTIVE_SLAVE]        = { .type = NLA_U32 },
+#ifdef IFLA_BOND_MIIMON
+        [IFLA_BOND_MIIMON]              = { .type = NLA_U32 },
+        [IFLA_BOND_UPDELAY]             = { .type = NLA_U32 },
+        [IFLA_BOND_DOWNDELAY]           = { .type = NLA_U32 },
+        [IFLA_BOND_USE_CARRIER]         = { .type = NLA_U8 },
+        [IFLA_BOND_ARP_INTERVAL]        = { .type = NLA_U32 },
+/*
+        [IFLA_BOND_ARP_IP_TARGET]       = { .type = NLA_NESTED },
+*/
+        [IFLA_BOND_ARP_VALIDATE]        = { .type = NLA_U32 },
+        [IFLA_BOND_ARP_ALL_TARGETS]     = { .type = NLA_U32 },
+        [IFLA_BOND_PRIMARY]             = { .type = NLA_U32 },
+        [IFLA_BOND_PRIMARY_RESELECT]    = { .type = NLA_U8 },
+        [IFLA_BOND_FAIL_OVER_MAC]       = { .type = NLA_U8 },
+        [IFLA_BOND_XMIT_HASH_POLICY]    = { .type = NLA_U8 },
+        [IFLA_BOND_RESEND_IGMP]         = { .type = NLA_U32 },
+        [IFLA_BOND_NUM_PEER_NOTIF]      = { .type = NLA_U8 },
+        [IFLA_BOND_ALL_SLAVES_ACTIVE]   = { .type = NLA_U8 },
+        [IFLA_BOND_MIN_LINKS]           = { .type = NLA_U32 },
+        [IFLA_BOND_LP_INTERVAL]         = { .type = NLA_U32 },
+        [IFLA_BOND_PACKETS_PER_SLAVE]   = { .type = NLA_U32 },
+        [IFLA_BOND_AD_LACP_RATE]        = { .type = NLA_U8 },
+        [IFLA_BOND_AD_SELECT]           = { .type = NLA_U8 },
+/*
+        [IFLA_BOND_AD_INFO]             = { .type = NLA_NESTED },
+*/
+#endif
+};
+
+typedef enum NLUnionLinkInfoData {
+        NL_UNION_LINK_INFO_DATA_BOND,
+        NL_UNION_LINK_INFO_DATA_BRIDGE,
+        NL_UNION_LINK_INFO_DATA_VLAN,
+        NL_UNION_LINK_INFO_DATA_VETH,
+        NL_UNION_LINK_INFO_DATA_MACVLAN,
+        _NL_UNION_LINK_INFO_DATA_MAX,
+        _NL_UNION_LINK_INFO_DATA_INVALID = -1
+} NLUnionLinkInfoData;
+
+const char *nl_union_link_info_data_to_string(NLUnionLinkInfoData p) _const_;
+NLUnionLinkInfoData nl_union_link_info_data_from_string(const char *p) _pure_;
+
+static const char* const nl_union_link_info_data_table[_NL_UNION_LINK_INFO_DATA_MAX] = {
+        [NL_UNION_LINK_INFO_DATA_BOND] = "bond",
+        [NL_UNION_LINK_INFO_DATA_BRIDGE] = "bridge",
+        [NL_UNION_LINK_INFO_DATA_VLAN] = "vlan",
+        [NL_UNION_LINK_INFO_DATA_VETH] = "veth",
+        [NL_UNION_LINK_INFO_DATA_MACVLAN] = "macvlan",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(nl_union_link_info_data, NLUnionLinkInfoData);
+
+static const NLTypeSystem rtnl_link_info_data_type_systems[_NL_UNION_LINK_INFO_DATA_MAX] = {
+        [NL_UNION_LINK_INFO_DATA_BRIDGE] =  { .max = ELEMENTSOF(rtnl_link_info_data_bridge_types) - 1,
+                                              .types = rtnl_link_info_data_bridge_types },
+        [NL_UNION_LINK_INFO_DATA_VLAN] =    { .max = ELEMENTSOF(rtnl_link_info_data_vlan_types) - 1,
+                                              .types = rtnl_link_info_data_vlan_types },
+        [NL_UNION_LINK_INFO_DATA_VETH] =    { .max = ELEMENTSOF(rtnl_link_info_data_veth_types) - 1,
+                                              .types = rtnl_link_info_data_veth_types },
+        [NL_UNION_LINK_INFO_DATA_MACVLAN] = { .max = ELEMENTSOF(rtnl_link_info_data_macvlan_types) - 1,
+                                              .types = rtnl_link_info_data_macvlan_types },
+};
+
+static const NLTypeSystemUnion rtnl_link_info_data_type_system_union = {
+        .num = _NL_UNION_LINK_INFO_DATA_MAX,
+        .lookup = nl_union_link_info_data_from_string,
+        .type_systems = rtnl_link_info_data_type_systems,
+        .match = IFLA_INFO_KIND,
+};
+
+static const NLType rtnl_link_info_types[IFLA_INFO_MAX + 1] = {
+        [IFLA_INFO_KIND]        = { .type = NLA_STRING },
+        [IFLA_INFO_DATA]        = { .type = NLA_UNION, .type_system_union = &rtnl_link_info_data_type_system_union},
+/*
+        [IFLA_INFO_XSTATS],
+        [IFLA_INFO_SLAVE_KIND]  = { .type = NLA_STRING },
+        [IFLA_INFO_SLAVE_DATA]  = { .type = NLA_NESTED },
+*/
+};
+
+static const NLTypeSystem rtnl_link_info_type_system = {
+        .max = ELEMENTSOF(rtnl_link_info_types) - 1,
+        .types = rtnl_link_info_types,
+};
+
+static const NLType rtnl_link_types[IFLA_MAX + 1] = {
+        [IFLA_ADDRESS]          = { .type = NLA_ETHER_ADDR, },
+        [IFLA_BROADCAST]        = { .type = NLA_ETHER_ADDR, },
+        [IFLA_IFNAME]           = { .type = NLA_STRING, .size = IFNAMSIZ - 1, },
+        [IFLA_MTU]              = { .type = NLA_U32 },
+        [IFLA_LINK]             = { .type = NLA_U32 },
+/*
+        [IFLA_QDISC],
+        [IFLA_STATS],
+        [IFLA_COST],
+        [IFLA_PRIORITY],
+*/
+        [IFLA_MASTER]           = { .type = NLA_U32 },
+/*
+        [IFLA_WIRELESS],
+        [IFLA_PROTINFO],
+*/
+        [IFLA_TXQLEN]           = { .type = NLA_U32 },
+/*
+        [IFLA_MAP]              = { .len = sizeof(struct rtnl_link_ifmap) },
+*/
+        [IFLA_WEIGHT]           = { .type = NLA_U32 },
+        [IFLA_OPERSTATE]        = { .type = NLA_U8 },
+        [IFLA_LINKMODE]         = { .type = NLA_U8 },
+        [IFLA_LINKINFO]         = { .type = NLA_NESTED, .type_system = &rtnl_link_info_type_system },
+        [IFLA_NET_NS_PID]       = { .type = NLA_U32 },
+        [IFLA_IFALIAS]          = { .type = NLA_STRING, .size = IFALIASZ - 1 },
+/*
+        [IFLA_NUM_VF],
+        [IFLA_VFINFO_LIST]      = {. type = NLA_NESTED, },
+        [IFLA_STATS64],
+        [IFLA_VF_PORTS]         = { .type = NLA_NESTED },
+        [IFLA_PORT_SELF]        = { .type = NLA_NESTED },
+        [IFLA_AF_SPEC]          = { .type = NLA_NESTED },
+        [IFLA_VF_PORTS],
+        [IFLA_PORT_SELF],
+        [IFLA_AF_SPEC],
+*/
+        [IFLA_GROUP]            = { .type = NLA_U32 },
+        [IFLA_NET_NS_FD]        = { .type = NLA_U32 },
+        [IFLA_EXT_MASK]         = { .type = NLA_U32 },
+        [IFLA_PROMISCUITY]      = { .type = NLA_U32 },
+        [IFLA_NUM_TX_QUEUES]    = { .type = NLA_U32 },
+        [IFLA_NUM_RX_QUEUES]    = { .type = NLA_U32 },
+        [IFLA_CARRIER]          = { .type = NLA_U8 },
+/*
+        [IFLA_PHYS_PORT_ID]     = { .type = NLA_BINARY, .len = MAX_PHYS_PORT_ID_LEN },
+*/
+};
+
+static const NLTypeSystem rtnl_link_type_system = {
+        .max = ELEMENTSOF(rtnl_link_types) - 1,
+        .types = rtnl_link_types,
+};
+
+static const NLType rtnl_address_types[IFA_MAX + 1] = {
+        [IFA_ADDRESS]           = { .type = NLA_IN_ADDR },
+        [IFA_LOCAL]             = { .type = NLA_IN_ADDR },
+        [IFA_LABEL]             = { .type = NLA_STRING, .size = IFNAMSIZ - 1 },
+        [IFA_BROADCAST]         = { .type = NLA_IN_ADDR }, /* 6? */
+/*
+        [IFA_ANYCAST],
+        [IFA_CACHEINFO]         = { .len = sizeof(struct ifa_cacheinfo) },
+        [IFA_MULTICAST],
+*/
+#ifdef IFA_FLAGS
+        [IFA_FLAGS]             = { .type = NLA_U32 },
+#endif
+};
+
+static const NLTypeSystem rtnl_address_type_system = {
+        .max = ELEMENTSOF(rtnl_address_types) - 1,
+        .types = rtnl_address_types,
+};
+
+static const NLType rtnl_route_types[RTA_MAX + 1] = {
+        [RTA_DST]               = { .type = NLA_IN_ADDR }, /* 6? */
+        [RTA_SRC]               = { .type = NLA_IN_ADDR }, /* 6? */
+        [RTA_IIF]               = { .type = NLA_U32 },
+        [RTA_OIF]               = { .type = NLA_U32 },
+        [RTA_GATEWAY]           = { .type = NLA_IN_ADDR },
+        [RTA_PRIORITY]          = { .type = NLA_U32 },
+        [RTA_PREFSRC]           = { .type = NLA_IN_ADDR }, /* 6? */
+/*
+        [RTA_METRICS]           = { .type = NLA_NESTED },
+        [RTA_MULTIPATH]         = { .len = sizeof(struct rtnexthop) },
+*/
+        [RTA_FLOW]              = { .type = NLA_U32 }, /* 6? */
+/*
+        RTA_CACHEINFO,
+        RTA_TABLE,
+        RTA_MARK,
+        RTA_MFC_STATS,
+*/
+};
+
+static const NLTypeSystem rtnl_route_type_system = {
+        .max = ELEMENTSOF(rtnl_route_types) - 1,
+        .types = rtnl_route_types,
+};
+
+static const NLType rtnl_types[RTM_MAX + 1] = {
+        [NLMSG_ERROR]  = { .type = NLA_META, .size = sizeof(struct nlmsgerr) },
+        [RTM_NEWLINK]  = { .type = NLA_NESTED, .type_system = &rtnl_link_type_system, .size = sizeof(struct ifinfomsg) },
+        [RTM_DELLINK]  = { .type = NLA_NESTED, .type_system = &rtnl_link_type_system, .size = sizeof(struct ifinfomsg) },
+        [RTM_GETLINK]  = { .type = NLA_NESTED, .type_system = &rtnl_link_type_system, .size = sizeof(struct ifinfomsg) },
+        [RTM_SETLINK]  = { .type = NLA_NESTED, .type_system = &rtnl_link_type_system, .size = sizeof(struct ifinfomsg) },
+        [RTM_NEWADDR]  = { .type = NLA_NESTED, .type_system = &rtnl_address_type_system, .size = sizeof(struct ifaddrmsg) },
+        [RTM_DELADDR]  = { .type = NLA_NESTED, .type_system = &rtnl_address_type_system, .size = sizeof(struct ifaddrmsg) },
+        [RTM_GETADDR]  = { .type = NLA_NESTED, .type_system = &rtnl_address_type_system, .size = sizeof(struct ifaddrmsg) },
+        [RTM_NEWROUTE] = { .type = NLA_NESTED, .type_system = &rtnl_route_type_system, .size = sizeof(struct rtmsg) },
+        [RTM_DELROUTE] = { .type = NLA_NESTED, .type_system = &rtnl_route_type_system, .size = sizeof(struct rtmsg) },
+        [RTM_GETROUTE] = { .type = NLA_NESTED, .type_system = &rtnl_route_type_system, .size = sizeof(struct rtmsg) },
+};
+
+const NLTypeSystem rtnl_type_system = {
+        .max = ELEMENTSOF(rtnl_types) - 1,
+        .types = rtnl_types,
+};
+
+int type_system_get_type(const NLTypeSystem *type_system, const NLType **ret, uint16_t type) {
+        const NLType *nl_type;
+
+        assert(ret);
+
+        if (!type_system)
+                type_system = &rtnl_type_system;
+
+        assert(type_system->types);
+
+        if (type > type_system->max)
+                return -ENOTSUP;
+
+        nl_type = &type_system->types[type];
+
+        if (nl_type->type == NLA_UNSPEC)
+                return -ENOTSUP;
+
+        *ret = nl_type;
+
+        return 0;
+}
+
+int type_system_get_type_system(const NLTypeSystem *type_system, const NLTypeSystem **ret, uint16_t type) {
+        const NLType *nl_type;
+        int r;
+
+        assert(ret);
+
+        r = type_system_get_type(type_system, &nl_type, type);
+        if (r < 0)
+                return r;
+
+        assert_return(nl_type->type == NLA_NESTED, -EINVAL);
+
+        assert(nl_type->type_system);
+
+        *ret = nl_type->type_system;
+
+        return 0;
+}
+
+int type_system_get_type_system_union(const NLTypeSystem *type_system, const NLTypeSystemUnion **ret, uint16_t type) {
+        const NLType *nl_type;
+        int r;
+
+        assert(ret);
+
+        r = type_system_get_type(type_system, &nl_type, type);
+        if (r < 0)
+                return r;
+
+        assert_return(nl_type->type == NLA_UNION, -EINVAL);
+
+        assert(nl_type->type_system_union);
+
+        *ret = nl_type->type_system_union;
+
+        return 0;
+}
+
+int type_system_union_get_type_system(const NLTypeSystemUnion *type_system_union, const NLTypeSystem **ret, const char *key) {
+        int type;
+
+        assert(type_system_union);
+        assert(type_system_union->lookup);
+        assert(type_system_union->type_systems);
+        assert(ret);
+        assert(key);
+
+        type = type_system_union->lookup(key);
+        if (type < 0)
+                return -ENOTSUP;
+
+        assert(type < type_system_union->num);
+
+        *ret = &type_system_union->type_systems[type];
+
+        return 0;
+}