tipc: add link get/dump to new netlink api

Add TIPC_NL_LINK_GET command to the new tipc netlink API.

This command supports dumping all information about all links
(including the broadcast link) or getting all information about a
specific link (not the broadcast link).

The information about a link includes name, transmission info,
properties and link statistics.

As the tipc broadcast link is special we unfortunately have to treat
it specially. It is a deliberate decision not to abstract the
broadcast link on this (API) level.

Netlink logical layout of link response message:
    -> port
        -> name
        -> MTU
        -> RX
        -> TX
        -> up flag
        -> active flag
        -> properties
           -> priority
           -> tolerance
           -> window
        -> statistics
            -> rx_info
            -> rx_fragments
            -> rx_fragmented
            -> rx_bundles
            -> rx_bundled
            -> tx_info
            -> tx_fragments
            -> tx_fragmented
            -> tx_bundles
            -> tx_bundled
            -> msg_prof_tot
            -> msg_len_cnt
            -> msg_len_tot
            -> msg_len_p0
            -> msg_len_p1
            -> msg_len_p2
            -> msg_len_p3
            -> msg_len_p4
            -> msg_len_p5
            -> msg_len_p6
            -> rx_states
            -> rx_probes
            -> rx_nacks
            -> rx_deferred
            -> tx_states
            -> tx_probes
            -> tx_nacks
            -> tx_acks
            -> retransmitted
            -> duplicates
            -> link_congs
            -> max_queue
            -> avg_queue

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 413 insertions, 1 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index b8670bf262e2..dcf3589e3cc5 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -767,6 +767,117 @@ void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action)
         tipc_bclink_unlock();
 }
 
+int __tipc_nl_add_bc_link_stat(struct sk_buff *skb, struct tipc_stats *stats)
+{
+        int i;
+        struct nlattr *nest;
+
+        struct nla_map {
+                __u32 key;
+                __u32 val;
+        };
+
+        struct nla_map map[] = {
+                {TIPC_NLA_STATS_RX_INFO, stats->recv_info},
+                {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
+                {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
+                {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
+                {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
+                {TIPC_NLA_STATS_TX_INFO, stats->sent_info},
+                {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
+                {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
+                {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
+                {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
+                {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
+                {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
+                {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
+                {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
+                {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
+                {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
+                {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
+                {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
+                {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
+                        (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
+        };
+
+        nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
+        if (!nest)
+                return -EMSGSIZE;
+
+        for (i = 0; i <  ARRAY_SIZE(map); i++)
+                if (nla_put_u32(skb, map[i].key, map[i].val))
+                        goto msg_full;
+
+        nla_nest_end(skb, nest);
+
+        return 0;
+msg_full:
+        nla_nest_cancel(skb, nest);
+
+        return -EMSGSIZE;
+}
+
+int tipc_nl_add_bc_link(struct tipc_nl_msg *msg)
+{
+        int err;
+        void *hdr;
+        struct nlattr *attrs;
+        struct nlattr *prop;
+
+        if (!bcl)
+                return 0;
+
+        tipc_bclink_lock();
+
+        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
+                          NLM_F_MULTI, TIPC_NL_LINK_GET);
+        if (!hdr)
+                return -EMSGSIZE;
+
+        attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
+        if (!attrs)
+                goto msg_full;
+
+        /* The broadcast link is always up */
+        if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
+                goto attr_msg_full;
+
+        if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
+                goto attr_msg_full;
+        if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, bcl->next_in_no))
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, bcl->next_out_no))
+                goto attr_msg_full;
+
+        prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
+        if (!prop)
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->queue_limit[0]))
+                goto prop_msg_full;
+        nla_nest_end(msg->skb, prop);
+
+        err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
+        if (err)
+                goto attr_msg_full;
+
+        tipc_bclink_unlock();
+        nla_nest_end(msg->skb, attrs);
+        genlmsg_end(msg->skb, hdr);
+
+        return 0;
+
+prop_msg_full:
+        nla_nest_cancel(msg->skb, prop);
+attr_msg_full:
+        nla_nest_cancel(msg->skb, attrs);
+msg_full:
+        tipc_bclink_unlock();
+        genlmsg_cancel(msg->skb, hdr);
+
+        return -EMSGSIZE;
+}
 
 int tipc_bclink_stats(char *buf, const u32 buf_size)
 {
diff --git a/net/tipc/bcast.h b/net/tipc/bcast.h
index e7b0f85a82bc..443de084d3e8 100644
--- a/net/tipc/bcast.h
+++ b/net/tipc/bcast.h
@@ -37,6 +37,8 @@
 #ifndef _TIPC_BCAST_H
 #define _TIPC_BCAST_H
 
+#include "netlink.h"
+
 #define MAX_NODES 4096
 #define WSIZE 32
 #define TIPC_BCLINK_RESET 1
@@ -100,4 +102,6 @@ void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action);
 uint  tipc_bclink_get_mtu(void);
 int tipc_bclink_xmit(struct sk_buff *buf);
 void tipc_bclink_wakeup_users(void);
+int tipc_nl_add_bc_link(struct tipc_nl_msg *msg);
+
 #endif
diff --git a/net/tipc/link.c b/net/tipc/link.c
index e7f365012bd1..bdc4b5e5bf56 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -36,6 +36,7 @@
 
 #include "core.h"
 #include "link.h"
+#include "bcast.h"
 #include "socket.h"
 #include "name_distr.h"
 #include "discover.h"
@@ -51,6 +52,22 @@ static const char *link_co_err = "Link changeover error, ";
 static const char *link_rst_msg = "Resetting link ";
 static const char *link_unk_evt = "Unknown link event ";
 
+static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
+        [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
+        [TIPC_NLA_LINK_NAME] = {
+                .type = NLA_STRING,
+                .len = TIPC_MAX_LINK_NAME
+        },
+        [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
+        [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
+        [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
+        [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
+        [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
+        [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
+        [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
+        [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
+};
+
 /* Properties valid for media, bearar and link */
 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
@@ -2423,3 +2440,273 @@ int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
 
         return 0;
 }
+
+int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
+{
+        int i;
+        struct nlattr *stats;
+
+        struct nla_map {
+                u32 key;
+                u32 val;
+        };
+
+        struct nla_map map[] = {
+                {TIPC_NLA_STATS_RX_INFO, s->recv_info},
+                {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
+                {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
+                {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
+                {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
+                {TIPC_NLA_STATS_TX_INFO, s->sent_info},
+                {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
+                {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
+                {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
+                {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
+                {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
+                        s->msg_length_counts : 1},
+                {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
+                {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
+                {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
+                {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
+                {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
+                {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
+                {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
+                {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
+                {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
+                {TIPC_NLA_STATS_RX_STATES, s->recv_states},
+                {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
+                {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
+                {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
+                {TIPC_NLA_STATS_TX_STATES, s->sent_states},
+                {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
+                {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
+                {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
+                {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
+                {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
+                {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
+                {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
+                {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
+                        (s->accu_queue_sz / s->queue_sz_counts) : 0}
+        };
+
+        stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
+        if (!stats)
+                return -EMSGSIZE;
+
+        for (i = 0; i <  ARRAY_SIZE(map); i++)
+                if (nla_put_u32(skb, map[i].key, map[i].val))
+                        goto msg_full;
+
+        nla_nest_end(skb, stats);
+
+        return 0;
+msg_full:
+        nla_nest_cancel(skb, stats);
+
+        return -EMSGSIZE;
+}
+
+/* Caller should hold appropriate locks to protect the link */
+int __tipc_nl_add_link(struct tipc_nl_msg *msg, struct tipc_link *link)
+{
+        int err;
+        void *hdr;
+        struct nlattr *attrs;
+        struct nlattr *prop;
+
+        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
+                          NLM_F_MULTI, TIPC_NL_LINK_GET);
+        if (!hdr)
+                return -EMSGSIZE;
+
+        attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
+        if (!attrs)
+                goto msg_full;
+
+        if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
+                        tipc_cluster_mask(tipc_own_addr)))
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->max_pkt))
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no))
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->next_out_no))
+                goto attr_msg_full;
+
+        if (tipc_link_is_up(link))
+                if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
+                        goto attr_msg_full;
+        if (tipc_link_is_active(link))
+                if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
+                        goto attr_msg_full;
+
+        prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
+        if (!prop)
+                goto attr_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
+                        link->queue_limit[TIPC_LOW_IMPORTANCE]))
+                goto prop_msg_full;
+        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
+                goto prop_msg_full;
+        nla_nest_end(msg->skb, prop);
+
+        err = __tipc_nl_add_stats(msg->skb, &link->stats);
+        if (err)
+                goto attr_msg_full;
+
+        nla_nest_end(msg->skb, attrs);
+        genlmsg_end(msg->skb, hdr);
+
+        return 0;
+
+prop_msg_full:
+        nla_nest_cancel(msg->skb, prop);
+attr_msg_full:
+        nla_nest_cancel(msg->skb, attrs);
+msg_full:
+        genlmsg_cancel(msg->skb, hdr);
+
+        return -EMSGSIZE;
+}
+
+/* Caller should hold node lock  */
+int __tipc_nl_add_node_links(struct tipc_nl_msg *msg, struct tipc_node *node,
+                             u32 *prev_link)
+{
+        u32 i;
+        int err;
+
+        for (i = *prev_link; i < MAX_BEARERS; i++) {
+                *prev_link = i;
+
+                if (!node->links[i])
+                        continue;
+
+                err = __tipc_nl_add_link(msg, node->links[i]);
+                if (err)
+                        return err;
+        }
+        *prev_link = 0;
+
+        return 0;
+}
+
+int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        struct tipc_node *node;
+        struct tipc_nl_msg msg;
+        u32 prev_node = cb->args[0];
+        u32 prev_link = cb->args[1];
+        int done = cb->args[2];
+        int err;
+
+        if (done)
+                return 0;
+
+        msg.skb = skb;
+        msg.portid = NETLINK_CB(cb->skb).portid;
+        msg.seq = cb->nlh->nlmsg_seq;
+
+        rcu_read_lock();
+
+        if (prev_node) {
+                node = tipc_node_find(prev_node);
+                if (!node) {
+                        /* We never set seq or call nl_dump_check_consistent()
+                         * this means that setting prev_seq here will cause the
+                         * consistence check to fail in the netlink callback
+                         * handler. Resulting in the last NLMSG_DONE message
+                         * having the NLM_F_DUMP_INTR flag set.
+                         */
+                        cb->prev_seq = 1;
+                        goto out;
+                }
+
+                list_for_each_entry_continue_rcu(node, &tipc_node_list, list) {
+                        tipc_node_lock(node);
+                        err = __tipc_nl_add_node_links(&msg, node, &prev_link);
+                        tipc_node_unlock(node);
+                        if (err)
+                                goto out;
+
+                        prev_node = node->addr;
+                }
+        } else {
+                err = tipc_nl_add_bc_link(&msg);
+                if (err)
+                        goto out;
+
+                list_for_each_entry_rcu(node, &tipc_node_list, list) {
+                        tipc_node_lock(node);
+                        err = __tipc_nl_add_node_links(&msg, node, &prev_link);
+                        tipc_node_unlock(node);
+                        if (err)
+                                goto out;
+
+                        prev_node = node->addr;
+                }
+        }
+        done = 1;
+out:
+        rcu_read_unlock();
+
+        cb->args[0] = prev_node;
+        cb->args[1] = prev_link;
+        cb->args[2] = done;
+
+        return skb->len;
+}
+
+int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
+{
+        struct sk_buff *ans_skb;
+        struct tipc_nl_msg msg;
+        struct tipc_link *link;
+        struct tipc_node *node;
+        char *name;
+        int bearer_id;
+        int err;
+
+        if (!info->attrs[TIPC_NLA_LINK_NAME])
+                return -EINVAL;
+
+        name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
+        node = tipc_link_find_owner(name, &bearer_id);
+        if (!node)
+                return -EINVAL;
+
+        ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+        if (!ans_skb)
+                return -ENOMEM;
+
+        msg.skb = ans_skb;
+        msg.portid = info->snd_portid;
+        msg.seq = info->snd_seq;
+
+        tipc_node_lock(node);
+        link = node->links[bearer_id];
+        if (!link) {
+                err = -EINVAL;
+                goto err_out;
+        }
+
+        err = __tipc_nl_add_link(&msg, link);
+        if (err)
+                goto err_out;
+
+        tipc_node_unlock(node);
+
+        return genlmsg_reply(ans_skb, info);
+
+err_out:
+        tipc_node_unlock(node);
+        nlmsg_free(ans_skb);
+
+        return err;
+}
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 4338294f20d4..8e3542a4a037 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -240,6 +240,8 @@ void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window);
 void tipc_link_retransmit(struct tipc_link *l_ptr,
                           struct sk_buff *start, u32 retransmits);
 
+int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb);
+int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info);
 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
 
 /*
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 9bc64aaff466..ea168b889caa 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -38,6 +38,7 @@
 #include "config.h"
 #include "socket.h"
 #include "bearer.h"
+#include "link.h"
 #include <net/genetlink.h>
 
 static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
@@ -74,7 +75,8 @@ static const struct nla_policy tipc_nl_policy[TIPC_NLA_MAX + 1] = {
         [TIPC_NLA_UNSPEC]       = { .type = NLA_UNSPEC, },
         [TIPC_NLA_BEARER]       = { .type = NLA_NESTED, },
         [TIPC_NLA_SOCK]         = { .type = NLA_NESTED, },
-        [TIPC_NLA_PUBL]         = { .type = NLA_NESTED, }
+        [TIPC_NLA_PUBL]         = { .type = NLA_NESTED, },
+        [TIPC_NLA_LINK]         = { .type = NLA_NESTED, },
 };
 
 /* Legacy ASCII API */
@@ -136,6 +138,12 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
                 .cmd    = TIPC_NL_PUBL_GET,
                 .dumpit = tipc_nl_publ_dump,
                 .policy = tipc_nl_policy,
+        },
+        {
+                .cmd    = TIPC_NL_LINK_GET,
+                .doit   = tipc_nl_link_get,
+                .dumpit = tipc_nl_link_dump,
+                .policy = tipc_nl_policy,
         }
 };