Subject: Re: [PATCH v2] net: introduce helper macro for_each_cmsghdr

From: Gu Zheng <[email-masked]>
Date: Wed, 10 Dec 2014 09:56:10 +0800

There's a mistake in this patch, please ignore it.
Sorry for the noise.

Regards,
Gu
On 12/10/2014 09:39 AM, Gu Zheng wrote:

> Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating
> cmsghdr from msghdr, just cleanup. 
> 
> 
> Signed-off-by: Gu Zheng <[email-masked]>
> ---
> v2: use the lower-case macro name as Joe suggested.
> ---
>  .../networking/timestamping/timestamping.c         |    4 +---
>  .../networking/timestamping/txtimestamp.c          |    4 +---
>  crypto/af_alg.c                                    |    2 +-
>  include/linux/socket.h                             |    4 ++++
>  net/core/scm.c                                     |    3 +--
>  net/dccp/proto.c                                   |    5 ++---
>  net/ipv4/ip_sockglue.c                             |    2 +-
>  net/ipv6/datagram.c                                |    2 +-
>  net/iucv/af_iucv.c                                 |    4 +---
>  net/rds/send.c                                     |    4 ++--
>  net/rxrpc/ar-output.c                              |    2 +-
>  net/sctp/socket.c                                  |    3 +--
>  12 files changed, 17 insertions(+), 22 deletions(-)
> 
> diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c
> index 5cdfd74..3106e88 100644
> --- a/Documentation/networking/timestamping/timestamping.c
> +++ b/Documentation/networking/timestamping/timestamping.c
> @@ -169,9 +169,7 @@ static void printpacket(struct msghdr *msg, int res,
>  	       res,
>  	       inet_ntoa(from_addr->sin_addr),
>  	       msg->msg_controllen);
> -	for (cmsg = CMSG_FIRSTHDR(msg);
> -	     cmsg;
> -	     cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		printf("   cmsg len %zu: ", cmsg->cmsg_len);
>  		switch (cmsg->cmsg_level) {
>  		case SOL_SOCKET:
> diff --git a/Documentation/networking/timestamping/txtimestamp.c b/Documentation/networking/timestamping/txtimestamp.c
> index b32fc2a..e44ef35 100644
> --- a/Documentation/networking/timestamping/txtimestamp.c
> +++ b/Documentation/networking/timestamping/txtimestamp.c
> @@ -149,9 +149,7 @@ static void __recv_errmsg_cmsg(struct msghdr *msg, int payload_len)
>  	struct scm_timestamping *tss = NULL;
>  	struct cmsghdr *cm;
>  
> -	for (cm = CMSG_FIRSTHDR(msg);
> -	     cm && cm->cmsg_len;
> -	     cm = CMSG_NXTHDR(msg, cm)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (cm->cmsg_level == SOL_SOCKET &&
>  		    cm->cmsg_type == SCM_TIMESTAMPING) {
>  			tss = (void *) CMSG_DATA(cm);
> diff --git a/crypto/af_alg.c b/crypto/af_alg.c
> index 6a3ad80..3df7d53 100644
> --- a/crypto/af_alg.c
> +++ b/crypto/af_alg.c
> @@ -399,7 +399,7 @@ int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con)
>  {
>  	struct cmsghdr *cmsg;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg))
>  			return -EINVAL;
>  		if (cmsg->cmsg_level != SOL_ALG)
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index bb9b836..d4b592f 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -94,6 +94,10 @@ struct cmsghdr {
>  			     (cmsg)->cmsg_len <= (unsigned long) \
>  			     ((mhdr)->msg_controllen - \
>  			      ((char *)(cmsg) - (char *)(mhdr)->msg_control)))
> +#define for_each_cmsg_hdr(cmsg, msg)  \
> +	for (cmsg = CMSG_FIRSTHDR(msg); \
> +	     cmsg; \
> +	     cmsg = CMSG_NXTHDR(msg, cmsg))
>  
>  /*
>   *	Get the next cmsg header
> diff --git a/net/core/scm.c b/net/core/scm.c
> index b442e7e..e938c49 100644
> --- a/net/core/scm.c
> +++ b/net/core/scm.c
> @@ -129,8 +129,7 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
>  	struct cmsghdr *cmsg;
>  	int err;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg))
> -	{
> +	for_each_cmsghdr(cmsg, msg) {
>  		err = -EINVAL;
>  
>  		/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
> diff --git a/net/dccp/proto.c b/net/dccp/proto.c
> index 5ab6627..d449cc5 100644
> --- a/net/dccp/proto.c
> +++ b/net/dccp/proto.c
> @@ -703,7 +703,7 @@ EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
>  
>  static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
>  {
> -	struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
> +	struct cmsghdr *cmsg;
>  
>  	/*
>  	 * Assign an (opaque) qpolicy priority value to skb->priority.
> @@ -717,8 +717,7 @@ static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
>  	 */
>  	skb->priority = 0;
>  
> -	for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> -
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg))
>  			return -EINVAL;
>  
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 9daf217..14a6f71 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -192,7 +192,7 @@ int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc,
>  	int err, val;
>  	struct cmsghdr *cmsg;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg))
>  			return -EINVAL;
>  #if IS_ENABLED(CONFIG_IPV6)
> diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
> index 2cdc383..9895b98 100644
> --- a/net/ipv6/datagram.c
> +++ b/net/ipv6/datagram.c
> @@ -640,7 +640,7 @@ int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
>  	int len;
>  	int err = 0;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		int addr_type;
>  
>  		if (!CMSG_OK(msg, cmsg)) {
> diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
> index a089b6b..eae4e08 100644
> --- a/net/iucv/af_iucv.c
> +++ b/net/iucv/af_iucv.c
> @@ -1070,9 +1070,7 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
>  	txmsg.class = 0;
>  
>  	/* iterate over control messages */
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg;
> -		cmsg = CMSG_NXTHDR(msg, cmsg)) {
> -
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg)) {
>  			err = -EINVAL;
>  			goto out;
> diff --git a/net/rds/send.c b/net/rds/send.c
> index 0a64541..1accb3e 100644
> --- a/net/rds/send.c
> +++ b/net/rds/send.c
> @@ -826,7 +826,7 @@ static int rds_rm_size(struct msghdr *msg, int data_len)
>  	int cmsg_groups = 0;
>  	int retval;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg))
>  			return -EINVAL;
>  
> @@ -878,7 +878,7 @@ static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
>  	struct cmsghdr *cmsg;
>  	int ret = 0;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg))
>  			return -EINVAL;
>  
> diff --git a/net/rxrpc/ar-output.c b/net/rxrpc/ar-output.c
> index 0b4b9a7..f915e7e 100644
> --- a/net/rxrpc/ar-output.c
> +++ b/net/rxrpc/ar-output.c
> @@ -45,7 +45,7 @@ static int rxrpc_sendmsg_cmsg(struct rxrpc_sock *rx, struct msghdr *msg,
>  	if (msg->msg_controllen == 0)
>  		return -EINVAL;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, msg) {
>  		if (!CMSG_OK(msg, cmsg))
>  			return -EINVAL;
>  
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 634a2ab..58834d7 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -6592,8 +6592,7 @@ static int sctp_msghdr_parse(const struct msghdr *msg, sctp_cmsgs_t *cmsgs)
>  	struct cmsghdr *cmsg;
>  	struct msghdr *my_msg = (struct msghdr *)msg;
>  
> -	for (cmsg = CMSG_FIRSTHDR(msg); cmsg != NULL;
> -	     cmsg = CMSG_NXTHDR(my_msg, cmsg)) {
> +	for_each_cmsghdr(cmsg, my_msg) {
>  		if (!CMSG_OK(my_msg, cmsg))
>  			return -EINVAL;
>