Re: [PATCH net-next 3/5] vsock/test: add send_buf() utility function

[Arseniy Krasnov]

On 15.09.2023 15:14, Stefano Garzarella wrote:
> Move the code of send_byte() out in a new utility function that
> can be used to send a generic buffer.
> 
> This new function can be used when we need to send a custom
> buffer and not just a single 'A' byte.
> 
> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> ---
>  tools/testing/vsock/util.h |  2 +
>  tools/testing/vsock/util.c | 90 +++++++++++++++++++++++---------------
>  2 files changed, 56 insertions(+), 36 deletions(-)

Reviewed-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>

> 
> diff --git a/tools/testing/vsock/util.h b/tools/testing/vsock/util.h
> index fe31f267e67e..e5407677ce05 100644
> --- a/tools/testing/vsock/util.h
> +++ b/tools/testing/vsock/util.h
> @@ -42,6 +42,8 @@ int vsock_stream_accept(unsigned int cid, unsigned int port,
>  int vsock_seqpacket_accept(unsigned int cid, unsigned int port,
>  			   struct sockaddr_vm *clientaddrp);
>  void vsock_wait_remote_close(int fd);
> +void send_buf(int fd, const void *buf, size_t len, int flags,
> +	      ssize_t expected_ret);
>  void recv_buf(int fd, void *buf, size_t len, int flags, ssize_t expected_ret);
>  void send_byte(int fd, int expected_ret, int flags);
>  void recv_byte(int fd, int expected_ret, int flags);
> diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c
> index 2826902706e8..6779d5008b27 100644
> --- a/tools/testing/vsock/util.c
> +++ b/tools/testing/vsock/util.c
> @@ -211,6 +211,59 @@ int vsock_seqpacket_accept(unsigned int cid, unsigned int port,
>  	return vsock_accept(cid, port, clientaddrp, SOCK_SEQPACKET);
>  }
>  
> +/* Transmit bytes from a buffer and check the return value.
> + *
> + * expected_ret:
> + *  <0 Negative errno (for testing errors)
> + *   0 End-of-file
> + *  >0 Success (bytes successfully written)
> + */
> +void send_buf(int fd, const void *buf, size_t len, int flags,
> +	      ssize_t expected_ret)
> +{
> +	ssize_t nwritten = 0;
> +	ssize_t ret;
> +
> +	timeout_begin(TIMEOUT);
> +	do {
> +		ret = send(fd, buf + nwritten, len - nwritten, flags);
> +		timeout_check("send");
> +
> +		if (ret == 0 || (ret < 0 && errno != EINTR))
> +			break;
> +
> +		nwritten += ret;
> +	} while (nwritten < len);
> +	timeout_end();
> +
> +	if (expected_ret < 0) {
> +		if (ret != -1) {
> +			fprintf(stderr, "bogus send(2) return value %zd (expected %zd)\n",
> +				ret, expected_ret);
> +			exit(EXIT_FAILURE);
> +		}
> +		if (errno != -expected_ret) {
> +			perror("send");
> +			exit(EXIT_FAILURE);
> +		}
> +		return;
> +	}
> +
> +	if (ret < 0) {
> +		perror("send");
> +		exit(EXIT_FAILURE);
> +	}
> +
> +	if (nwritten != expected_ret) {
> +		if (ret == 0)
> +			fprintf(stderr, "unexpected EOF while sending bytes\n");
> +
> +		fprintf(stderr, "bogus send(2) bytes written %zd (expected %zd)\n",
> +			nwritten, expected_ret);
> +		exit(EXIT_FAILURE);
> +	}
> +}
> +
>  /* Receive bytes in a buffer and check the return value.
>   *
>   * expected_ret:
> @@ -273,43 +326,8 @@ void recv_buf(int fd, void *buf, size_t len, int flags, ssize_t expected_ret)
>  void send_byte(int fd, int expected_ret, int flags)
>  {
>  	const uint8_t byte = 'A';
> -	ssize_t nwritten;
> -
> -	timeout_begin(TIMEOUT);
> -	do {
> -		nwritten = send(fd, &byte, sizeof(byte), flags);
> -		timeout_check("write");
> -	} while (nwritten < 0 && errno == EINTR);
> -	timeout_end();
> -
> -	if (expected_ret < 0) {
> -		if (nwritten != -1) {
> -			fprintf(stderr, "bogus send(2) return value %zd\n",
> -				nwritten);
> -			exit(EXIT_FAILURE);
> -		}
> -		if (errno != -expected_ret) {
> -			perror("write");
> -			exit(EXIT_FAILURE);
> -		}
> -		return;
> -	}
>  
> -	if (nwritten < 0) {
> -		perror("write");
> -		exit(EXIT_FAILURE);
> -	}
> -	if (nwritten == 0) {
> -		if (expected_ret == 0)
> -			return;
> -
> -		fprintf(stderr, "unexpected EOF while sending byte\n");
> -		exit(EXIT_FAILURE);
> -	}
> -	if (nwritten != sizeof(byte)) {
> -		fprintf(stderr, "bogus send(2) return value %zd\n", nwritten);
> -		exit(EXIT_FAILURE);
> -	}
> +	send_buf(fd, &byte, sizeof(byte), flags, expected_ret);
>  }
>  
>  /* Receive one byte and check the return value.