Re: [PATCHv2 net-next 4/6] sctp: add the sctp_diag.c file

[Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>]

On Fri, Apr 08, 2016 at 10:51:56PM -0700, Eric Dumazet wrote:
> On Sat, 2016-04-09 at 12:53 +0800, Xin Long wrote:
> > This one will implement all the interface of inet_diag, inet_diag_handler.
> > which includes sctp_diag_dump, sctp_diag_dump_one and sctp_diag_get_info.
> 
> 
> > +static int inet_assoc_diag_fill(struct sock *sk,
> > +				struct sctp_association *asoc,
> > +				struct sk_buff *skb,
> > +				const struct inet_diag_req_v2 *req,
> > +				struct user_namespace *user_ns,
> > +				int portid, u32 seq, u16 nlmsg_flags,
> > +				const struct nlmsghdr *unlh)
> > +{
> > +	const struct inet_sock *inet = inet_sk(sk);
> > +	const struct inet_diag_handler *handler;
> > +	int ext = req->idiag_ext;
> > +	struct inet_diag_msg *r;
> > +	struct nlmsghdr  *nlh;
> > +	struct nlattr *attr;
> > +	void *info = NULL;
> > +	union sctp_addr laddr, paddr;
> > +	struct dst_entry *dst;
> > +	struct sctp_infox infox;
> > +
> > +	handler = inet_diag_get_handler(req->sdiag_protocol);
> > +	BUG_ON(!handler);
> > +
> > +	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
> > +			nlmsg_flags);
> > +	if (!nlh)
> > +		return -EMSGSIZE;
> > +
> > +	r = nlmsg_data(nlh);
> > +	BUG_ON(!sk_fullsock(sk));
> > +
> > +	laddr = list_entry(asoc->base.bind_addr.address_list.next,
> > +			   struct sctp_sockaddr_entry, list)->a;
> > +	paddr = asoc->peer.primary_path->ipaddr;
> > +	dst = asoc->peer.primary_path->dst;
> > +
> > +	r->idiag_family = sk->sk_family;
> > +	r->id.idiag_sport = htons(asoc->base.bind_addr.port);
> > +	r->id.idiag_dport = htons(asoc->peer.port);
> > +	r->id.idiag_if = dst ? dst->dev->ifindex : 0;
> > +	sock_diag_save_cookie(sk, r->id.idiag_cookie);
> > +
> > +#if IS_ENABLED(CONFIG_IPV6)
> > +	if (sk->sk_family == AF_INET6) {
> > +		*(struct in6_addr *)r->id.idiag_src = laddr.v6.sin6_addr;
> > +		*(struct in6_addr *)r->id.idiag_dst = paddr.v6.sin6_addr;
> > +	} else
> > +#endif
> > +	{
> > +		memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
> > +		memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
> > +
> > +		r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr;
> > +		r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr;
> > +	}
> > +
> > +	r->idiag_state = asoc->state;
> > +	r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX;
> > +	r->idiag_retrans = asoc->rtx_data_chunks;
> > +#define EXPIRES_IN_MS(tmo)  DIV_ROUND_UP((tmo - jiffies) * 1000, HZ)
> > +	r->idiag_expires =
> > +		EXPIRES_IN_MS(asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX]);
> > +#undef EXPIRES_IN_MS
> > +

vvv
> > +	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
> > +		goto errout;
> > +
> > +	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
> > +	 * hence this needs to be included regardless of socket family.
> > +	 */
> > +	if (ext & (1 << (INET_DIAG_TOS - 1)))
> > +		if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
> > +			goto errout;
> > +
> > +#if IS_ENABLED(CONFIG_IPV6)
> > +	if (r->idiag_family == AF_INET6) {
> > +		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
> > +			if (nla_put_u8(skb, INET_DIAG_TCLASS,
> > +				       inet6_sk(sk)->tclass) < 0)
> > +				goto errout;
> > +
> > +		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
> > +		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
> > +			goto errout;
> > +	}
> > +#endif
> > +
> > +	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
> > +	r->idiag_inode = sock_i_ino(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),
> > +		};
> > +
> 
> All this code looks familiar.
> 
> Why inet_sk_diag_fill() is not used instead ?

Actually we have an issue here. idiag_tmem is using sk_wmem_alloc_get()   
directly, but it shouldn't. SCTP supports using sndbuf per socket or      
per assoc on that socket. We need an if and report the correct value,     
as it's done in sctp_wspace().                                            

For inet_ep_diag_fill, it's reporting an endpoint, so this is not needed
as we don't have this option in there.                                    

> > +		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 errout;

Same happens in sock_diag_put_meminfo().

I highlighted the section that would have been common to
inet_sk_diag_fill() if it wasn't for this wmem_alloc difference using
vvv and ^^^ marks. There is one or another common lines out of it. I
suggest we try to factor out this common code but only from within these
two functions in sctp_diag, leaving inet_diag alone for now, just until
this soak a bit more.

> > +
> > +	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
> > +		attr = nla_reserve(skb, INET_DIAG_INFO,
> > +				   handler->idiag_info_size);
> > +		if (!attr)
> > +			goto errout;
> > +
> > +		info = nla_data(attr);
> > +	}
^^^

> > +	infox.sctpinfo = (struct sctp_info *)info;
> > +	infox.asoc = asoc;
> > +	handler->idiag_get_info(sk, r, &infox);
> > +
> > +	if (ext & (1 << (INET_DIAG_CONG - 1)))
> > +		if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
> > +			goto errout;

the above block is not common to inet_sk_diag_fill

> > +
> > +	if (inet_sctp_fill_laddrs(skb, &asoc->base.bind_addr.address_list))
> > +		goto errout;
> > +
> > +	if (inet_sctp_fill_paddrs(skb, asoc))
> > +		goto errout;
> > +
> > +	nlmsg_end(skb, nlh);
> > +	return 0;
> > +
> > +errout:
> > +	nlmsg_cancel(skb, nlh);
> > +	return -EMSGSIZE;
> > +}
> > +
> > +static int inet_ep_diag_fill(struct sock *sk, struct sctp_endpoint *ep,
> > +			     struct sk_buff *skb,
> > +			     const struct inet_diag_req_v2 *req,
> > +			     struct user_namespace *user_ns,
> > +			     u32 portid, u32 seq, u16 nlmsg_flags,
> > +			     const struct nlmsghdr *unlh)
> > +{
> > +	const struct inet_sock *inet = inet_sk(sk);
> > +	const struct inet_diag_handler *handler;
> > +	int ext = req->idiag_ext;
> > +	struct inet_diag_msg *r;
> > +	struct nlmsghdr  *nlh;
> > +	struct nlattr *attr;
> > +	void *info = NULL;
> > +	struct sctp_infox infox;
> > +
> > +	handler = inet_diag_get_handler(req->sdiag_protocol);
> > +	BUG_ON(!handler);
> > +
> > +	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
> > +			nlmsg_flags);
> > +	if (!nlh)
> > +		return -EMSGSIZE;
> > +
> > +	r = nlmsg_data(nlh);
> > +	BUG_ON(!sk_fullsock(sk));
> > +
> > +	inet_diag_msg_common_fill(r, sk);
> > +	r->idiag_state = sk->sk_state;
> > +	r->idiag_timer = 0;
> > +	r->idiag_retrans = 0;
> > +
> > +	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
> > +		goto errout;
> > +
> > +	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
> > +	 * hence this needs to be included regardless of socket family.
> > +	 */
> > +	if (ext & (1 << (INET_DIAG_TOS - 1)))
> > +		if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
> > +			goto errout;
> > +
> > +#if IS_ENABLED(CONFIG_IPV6)
> > +	if (r->idiag_family == AF_INET6) {
> > +		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
> > +			if (nla_put_u8(skb, INET_DIAG_TCLASS,
> > +				       inet6_sk(sk)->tclass) < 0)
> > +				goto errout;
> > +
> > +		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
> > +		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
> > +			goto errout;
> > +	}
> > +#endif
> > +
> > +	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
> > +	r->idiag_inode = sock_i_ino(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),
> > +		};
> > +
> 
> Again, looks a lot of duplication.
> 
> Also you missed that INET_DIAG_MEMINFO is kind of obsolete,
> now we have sock_diag_put_meminfo()
> 
> 
> > +		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 errout;
> > +
> > +	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
> > +		attr = nla_reserve(skb, INET_DIAG_INFO,
> > +				   handler->idiag_info_size);
> > +		if (!attr)
> > +			goto errout;
> > +
> > +		info = nla_data(attr);
> > +	}
> > +	infox.sctpinfo = (struct sctp_info *)info;
> > +	infox.asoc = NULL;
> > +	handler->idiag_get_info(sk, r, &infox);
> > +
> > +	if (inet_sctp_fill_laddrs(skb, &ep->base.bind_addr.address_list))
> > +		goto errout;
> > +
> > +	nlmsg_end(skb, nlh);
> > +	return 0;
> > +
> > +errout:
> > +	nlmsg_cancel(skb, nlh);
> > +	return -EMSGSIZE;
> > +}
> > +
> > +static size_t inet_assoc_attr_size(struct sctp_association *asoc)
> > +{
> > +	int addrlen = sizeof(struct sockaddr_storage);
> > +	int addrcnt = 0;
> > +	struct sctp_sockaddr_entry *laddr;
> > +
> > +	list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
> > +				list)
> > +		addrcnt++;
> > +
> > +	return	  nla_total_size(sizeof(struct tcp_info))
> 
> Are you sure you want to use tcp_info ???
> 
> > +		+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
> > +		+ nla_total_size(1) /* INET_DIAG_TOS */
> > +		+ nla_total_size(1) /* INET_DIAG_TCLASS */
> > +		+ nla_total_size(addrlen * asoc->peer.transport_count)
> > +		+ nla_total_size(addrlen * addrcnt)
> > +		+ nla_total_size(sizeof(struct inet_diag_meminfo))
> > +		+ nla_total_size(sizeof(struct inet_diag_msg))
> > +		+ nla_total_size(sizeof(struct sctp_info))
> > +		+ 64;
> > +}
> 
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>