inet_diag: Do not use RTA_PUT() macros

Also, no need to trim on nlmsg_put() failure, nothing has been added
yet.  We also want to use nlmsg_end(), nlmsg_new() and nlmsg_free().

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 59 deletions

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 27640e734cfd..38064a285cca 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -46,9 +46,6 @@ struct inet_diag_entry {
         u16 userlocks;
 };
 
-#define INET_DIAG_PUT(skb, attrtype, attrlen) \
-        RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
-
 static DEFINE_MUTEX(inet_diag_table_mutex);
 
 static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
@@ -78,28 +75,22 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
         const struct inet_sock *inet = inet_sk(sk);
         struct inet_diag_msg *r;
         struct nlmsghdr  *nlh;
+        struct nlattr *attr;
         void *info = NULL;
-        struct inet_diag_meminfo  *minfo = NULL;
-        unsigned char    *b = skb_tail_pointer(skb);
         const struct inet_diag_handler *handler;
         int ext = req->idiag_ext;
 
         handler = inet_diag_table[req->sdiag_protocol];
         BUG_ON(handler == NULL);
 
-        nlh = nlmsg_put(skb, pid, seq, unlh->nlmsg_type, sizeof(*r), 0);
-        if (!nlh) {
-                nlmsg_trim(skb, b);
+        nlh = nlmsg_put(skb, pid, seq, unlh->nlmsg_type, sizeof(*r),
+                        nlmsg_flags);
+        if (!nlh)
                 return -EMSGSIZE;
-        }
-        nlh->nlmsg_flags = nlmsg_flags;
 
         r = nlmsg_data(nlh);
         BUG_ON(sk->sk_state == TCP_TIME_WAIT);
 
-        if (ext & (1 << (INET_DIAG_MEMINFO - 1)))
-                minfo = INET_DIAG_PUT(skb, INET_DIAG_MEMINFO, sizeof(*minfo));
-
         r->idiag_family = sk->sk_family;
         r->idiag_state = sk->sk_state;
         r->idiag_timer = 0;
@@ -117,7 +108,8 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
          * hence this needs to be included regardless of socket family.
          */
         if (ext & (1 << (INET_DIAG_TOS - 1)))
-                RTA_PUT_U8(skb, INET_DIAG_TOS, inet->tos);
+                if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
+                        goto errout;
 
 #if IS_ENABLED(CONFIG_IPV6)
         if (r->idiag_family == AF_INET6) {
@@ -125,24 +117,31 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
 
                 *(struct in6_addr *)r->id.idiag_src = np->rcv_saddr;
                 *(struct in6_addr *)r->id.idiag_dst = np->daddr;
+
                 if (ext & (1 << (INET_DIAG_TCLASS - 1)))
-                        RTA_PUT_U8(skb, INET_DIAG_TCLASS, np->tclass);
+                        if (nla_put_u8(skb, INET_DIAG_TCLASS, np->tclass) < 0)
+                                goto errout;
         }
 #endif
 
         r->idiag_uid = sock_i_uid(sk);
         r->idiag_inode = sock_i_ino(sk);
 
-        if (minfo) {
-                minfo->idiag_rmem = sk_rmem_alloc_get(sk);
-                minfo->idiag_wmem = sk->sk_wmem_queued;
-                minfo->idiag_fmem = sk->sk_forward_alloc;
-                minfo->idiag_tmem = sk_wmem_alloc_get(sk);
+        if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
+                struct inet_diag_meminfo minfo = {
+                        .idiag_rmem = sk_rmem_alloc_get(sk),
+                        .idiag_wmem = sk->sk_wmem_queued,
+                        .idiag_fmem = sk->sk_forward_alloc,
+                        .idiag_tmem = sk_wmem_alloc_get(sk),
+                };
+
+                if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0)
+                        goto errout;
         }
 
         if (ext & (1 << (INET_DIAG_SKMEMINFO - 1)))
                 if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
-                        goto rtattr_failure;
+                        goto errout;
 
         if (icsk == NULL) {
                 handler->idiag_get_info(sk, r, NULL);
@@ -169,16 +168,20 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
         }
 #undef EXPIRES_IN_MS
 
-        if (ext & (1 << (INET_DIAG_INFO - 1)))
-                info = INET_DIAG_PUT(skb, INET_DIAG_INFO, sizeof(struct tcp_info));
+        if (ext & (1 << (INET_DIAG_INFO - 1))) {
+                attr = nla_reserve(skb, INET_DIAG_INFO,
+                                   sizeof(struct tcp_info));
+                if (!attr)
+                        goto errout;
 
-        if ((ext & (1 << (INET_DIAG_CONG - 1))) && icsk->icsk_ca_ops) {
-                const size_t len = strlen(icsk->icsk_ca_ops->name);
-
-                strcpy(INET_DIAG_PUT(skb, INET_DIAG_CONG, len + 1),
-                       icsk->icsk_ca_ops->name);
+                info = nla_data(attr);
         }
 
+        if ((ext & (1 << (INET_DIAG_CONG - 1))) && icsk->icsk_ca_ops)
+                if (nla_put_string(skb, INET_DIAG_CONG,
+                                   icsk->icsk_ca_ops->name) < 0)
+                        goto errout;
+
         handler->idiag_get_info(sk, r, info);
 
         if (sk->sk_state < TCP_TIME_WAIT &&
@@ -186,11 +189,10 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
                 icsk->icsk_ca_ops->get_info(sk, ext, skb);
 
 out:
-        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
-        return skb->len;
+        return nlmsg_end(skb, nlh);
 
-rtattr_failure:
-        nlmsg_trim(skb, b);
+errout:
+        nlmsg_cancel(skb, nlh);
         return -EMSGSIZE;
 }
 EXPORT_SYMBOL_GPL(inet_sk_diag_fill);
@@ -211,20 +213,16 @@ static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
 {
         long tmo;
         struct inet_diag_msg *r;
-        const unsigned char *previous_tail = skb_tail_pointer(skb);
-        struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq,
-                                         unlh->nlmsg_type, sizeof(*r), 0);
+        struct nlmsghdr *nlh;
 
-        if (!nlh) {
-                nlmsg_trim(skb, previous_tail);
+        nlh = nlmsg_put(skb, pid, seq, unlh->nlmsg_type, sizeof(*r),
+                        nlmsg_flags);
+        if (!nlh)
                 return -EMSGSIZE;
-        }
 
         r = nlmsg_data(nlh);
         BUG_ON(tw->tw_state != TCP_TIME_WAIT);
 
-        nlh->nlmsg_flags = nlmsg_flags;
-
         tmo = tw->tw_ttd - jiffies;
         if (tmo < 0)
                 tmo = 0;
@@ -253,8 +251,8 @@ static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
                 *(struct in6_addr *)r->id.idiag_dst = tw6->tw_v6_daddr;
         }
 #endif
-        nlh->nlmsg_len = skb_tail_pointer(skb) - previous_tail;
-        return skb->len;
+
+        return nlmsg_end(skb, nlh);
 }
 
 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
@@ -303,20 +301,20 @@ int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *in_s
         if (err)
                 goto out;
 
-        err = -ENOMEM;
-        rep = alloc_skb(NLMSG_SPACE((sizeof(struct inet_diag_msg) +
-                                     sizeof(struct inet_diag_meminfo) +
-                                     sizeof(struct tcp_info) + 64)),
-                        GFP_KERNEL);
-        if (!rep)
+        rep = nlmsg_new(sizeof(struct inet_diag_msg) +
+                        sizeof(struct inet_diag_meminfo) +
+                        sizeof(struct tcp_info) + 64, GFP_KERNEL);
+        if (!rep) {
+                err = -ENOMEM;
                 goto out;
+        }
 
         err = sk_diag_fill(sk, rep, req,
                            NETLINK_CB(in_skb).pid,
                            nlh->nlmsg_seq, 0, nlh);
         if (err < 0) {
                 WARN_ON(err == -EMSGSIZE);
-                kfree_skb(rep);
+                nlmsg_free(rep);
                 goto out;
         }
         err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
@@ -597,19 +595,16 @@ static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
 {
         const struct inet_request_sock *ireq = inet_rsk(req);
         struct inet_sock *inet = inet_sk(sk);
-        unsigned char *b = skb_tail_pointer(skb);
         struct inet_diag_msg *r;
         struct nlmsghdr *nlh;
         long tmo;
 
-        nlh = nlmsg_put(skb, pid, seq, unlh->nlmsg_type, sizeof(*r), 0);
-        if (!nlh) {
-                nlmsg_trim(skb, b);
-                return -1;
-        }
-        nlh->nlmsg_flags = NLM_F_MULTI;
-        r = nlmsg_data(nlh);
+        nlh = nlmsg_put(skb, pid, seq, unlh->nlmsg_type, sizeof(*r),
+                        NLM_F_MULTI);
+        if (!nlh)
+                return -EMSGSIZE;
 
+        r = nlmsg_data(nlh);
         r->idiag_family = sk->sk_family;
         r->idiag_state = TCP_SYN_RECV;
         r->idiag_timer = 1;
@@ -637,9 +632,8 @@ static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
                 *(struct in6_addr *)r->id.idiag_dst = inet6_rsk(req)->rmt_addr;
         }
 #endif
-        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 
-        return skb->len;
+        return nlmsg_end(skb, nlh);
 }
 
 static int inet_diag_dump_reqs(struct sk_buff *skb, struct sock *sk,