Re: [PATCH 10/24] tcp: rename functions that manage buffers

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Feb 02, 2024 at 03:11:37PM +0100, Laurent Vivier wrote:
> To separate these functions from the ones specific to TCP management,
> we are going to move it to a new file, but before that update their names
> to reflect their role.
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>  passt.c |  2 +-
>  tcp.c   | 84 ++++++++++++++++++++++++++++-----------------------------
>  tcp.h   |  2 +-
>  3 files changed, 44 insertions(+), 44 deletions(-)
> 
> diff --git a/passt.c b/passt.c
> index 44d3a0b0548c..10042a9b9789 100644
> --- a/passt.c
> +++ b/passt.c
> @@ -164,7 +164,7 @@ static void timer_init(struct ctx *c, const struct timespec *now)
>   */
>  void proto_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s)
>  {
> -	tcp_update_l2_buf(eth_d, eth_s);
> +	tcp_buf_update_l2(eth_d, eth_s);
>  	udp_update_l2_buf(eth_d, eth_s);
>  }
>  
> diff --git a/tcp.c b/tcp.c
> index cdbceed65033..640209533772 100644
> --- a/tcp.c
> +++ b/tcp.c
> @@ -383,7 +383,7 @@ struct tcp6_l2_head {	/* For MSS6 macro: keep in sync with tcp6_l2_buf_t */
>  #define ACK		(1 << 4)
>  /* Flags for internal usage */
>  #define DUP_ACK		(1 << 5)
> -#define ACK_IF_NEEDED	0		/* See tcp_send_flag() */
> +#define ACK_IF_NEEDED	0		/* See tcp_buf_send_flag() */
>  
>  #define OPT_EOL		0
>  #define OPT_NOP		1
> @@ -960,11 +960,11 @@ static uint16_t tcp_update_check_tcp6(struct ipv6hdr *ip6h)
>  }
>  
>  /**
> - * tcp_update_l2_buf() - Update L2 buffers with Ethernet and IPv4 addresses
> + * tcp_buf_update_l2() - Update L2 buffers with Ethernet and IPv4 addresses
>   * @eth_d:	Ethernet destination address, NULL if unchanged
>   * @eth_s:	Ethernet source address, NULL if unchanged
>   */
> -void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s)
> +void tcp_buf_update_l2(const unsigned char *eth_d, const unsigned char *eth_s)
>  {
>  	int i;
>  
> @@ -982,10 +982,10 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s)
>  }
>  
>  /**
> - * tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
> + * tcp_buf_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
>   * @c:		Execution context
>   */
> -static void tcp_sock4_iov_init(const struct ctx *c)
> +static void tcp_buf_sock4_iov_init(const struct ctx *c)
>  {
>  	struct iphdr iph = L2_BUF_IP4_INIT(IPPROTO_TCP);
>  	struct iovec *iov;
> @@ -1014,10 +1014,10 @@ static void tcp_sock4_iov_init(const struct ctx *c)
>  }
>  
>  /**
> - * tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
> + * tcp_buf_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
>   * @c:		Execution context
>   */
> -static void tcp_sock6_iov_init(const struct ctx *c)
> +static void tcp_buf_sock6_iov_init(const struct ctx *c)
>  {
>  	struct iovec *iov;
>  	int i;
> @@ -1277,10 +1277,10 @@ static void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
>  	} while (0)
>  
>  /**
> - * tcp_l2_flags_buf_flush() - Send out buffers for segments with no data (flags)
> + * tcp_buf_l2_flags_flush() - Send out buffers for segments with no data (flags)
>   * @c:		Execution context
>   */
> -static void tcp_l2_flags_buf_flush(const struct ctx *c)
> +static void tcp_buf_l2_flags_flush(const struct ctx *c)
>  {
>  	tap_send_frames(c, tcp6_l2_flags_iov, tcp6_l2_flags_buf_used);
>  	tcp6_l2_flags_buf_used = 0;
> @@ -1290,10 +1290,10 @@ static void tcp_l2_flags_buf_flush(const struct ctx *c)
>  }
>  
>  /**
> - * tcp_l2_data_buf_flush() - Send out buffers for segments with data
> + * tcp_buf_l2_data_flush() - Send out buffers for segments with data
>   * @c:		Execution context
>   */
> -static void tcp_l2_data_buf_flush(const struct ctx *c)
> +static void tcp_buf_l2_data_flush(const struct ctx *c)
>  {
>  	unsigned i;
>  	size_t m;
> @@ -1316,8 +1316,8 @@ static void tcp_l2_data_buf_flush(const struct ctx *c)
>  /* cppcheck-suppress [constParameterPointer, unmatchedSuppression] */
>  void tcp_defer_handler(struct ctx *c)
>  {
> -	tcp_l2_flags_buf_flush(c);
> -	tcp_l2_data_buf_flush(c);
> +	tcp_buf_l2_flags_flush(c);
> +	tcp_buf_l2_data_flush(c);
>  }
>  
>  static void tcp_set_tcp_header(struct tcphdr *th,
> @@ -1629,7 +1629,7 @@ static int do_tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags,
>  	return 1;
>  }
>  
> -static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
> +static int tcp_buf_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)

The functions above could reasonably be said to be part of the buffer
management, but I'm not convinced on this one - it's primary purpose
is to, well, send a flag, so it uses the buffers, but I wouldn't
really say it manages them.

>  {
>  	size_t optlen = 0;
>  	struct iovec *iov;
> @@ -1664,7 +1664,7 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
>  		}
>  
>  		if (tcp4_l2_flags_buf_used > ARRAY_SIZE(tcp4_l2_flags_buf) - 2)
> -			tcp_l2_flags_buf_flush(c);
> +			tcp_buf_l2_flags_flush(c);
>  	} else {
>  		struct tcp6_l2_flags_buf_t *b6;
>  
> @@ -1688,7 +1688,7 @@ static int tcp_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
>  		}
>  
>  		if (tcp6_l2_flags_buf_used > ARRAY_SIZE(tcp6_l2_flags_buf) - 2)
> -			tcp_l2_flags_buf_flush(c);
> +			tcp_buf_l2_flags_flush(c);
>  	}
>  
>  	return 0;
> @@ -1704,7 +1704,7 @@ static void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn)
>  	if (conn->events == CLOSED)
>  		return;
>  
> -	if (!tcp_send_flag(c, conn, RST))
> +	if (!tcp_buf_send_flag(c, conn, RST))
>  		conn_event(c, conn, CLOSED);
>  }
>  
> @@ -2024,7 +2024,7 @@ static void tcp_conn_from_tap(struct ctx *c,
>  	} else {
>  		tcp_get_sndbuf(conn);
>  
> -		if (tcp_send_flag(c, conn, SYN | ACK))
> +		if (tcp_buf_send_flag(c, conn, SYN | ACK))
>  			return;
>  
>  		conn_event(c, conn, TAP_SYN_ACK_SENT);
> @@ -2100,7 +2100,7 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
>  		iov = tcp4_l2_iov + tcp4_l2_buf_used++;
>  		iov->iov_len = tap_iov_len(c, &b->taph, ip_len);
>  		if (tcp4_l2_buf_used > ARRAY_SIZE(tcp4_l2_buf) - 1)
> -			tcp_l2_data_buf_flush(c);
> +			tcp_buf_l2_data_flush(c);
>  	} else if (CONN_V6(conn)) {
>  		struct tcp6_l2_buf_t *b = &tcp6_l2_buf[tcp6_l2_buf_used];
>  
> @@ -2112,12 +2112,12 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
>  		iov = tcp6_l2_iov + tcp6_l2_buf_used++;
>  		iov->iov_len = tap_iov_len(c, &b->taph, ip_len);
>  		if (tcp6_l2_buf_used > ARRAY_SIZE(tcp6_l2_buf) - 1)
> -			tcp_l2_data_buf_flush(c);
> +			tcp_buf_l2_data_flush(c);
>  	}
>  }
>  
>  /**
> - * tcp_data_from_sock() - Handle new data from socket, queue to tap, in window
> + * tcp_buf_data_from_sock() - Handle new data from socket, queue to tap, in window

Same with this one.

>   * @c:		Execution context
>   * @conn:	Connection pointer
>   *
> @@ -2125,7 +2125,7 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn,
>   *
>   * #syscalls recvmsg
>   */
> -static int tcp_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn)
> +static int tcp_buf_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn)
>  {
>  	uint32_t wnd_scaled = conn->wnd_from_tap << conn->ws_from_tap;
>  	int fill_bufs, send_bufs = 0, last_len, iov_rem = 0;
> @@ -2169,7 +2169,7 @@ static int tcp_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn)
>  
>  	if (( v4 && tcp4_l2_buf_used + fill_bufs > ARRAY_SIZE(tcp4_l2_buf)) ||
>  	    (!v4 && tcp6_l2_buf_used + fill_bufs > ARRAY_SIZE(tcp6_l2_buf))) {
> -		tcp_l2_data_buf_flush(c);
> +		tcp_buf_l2_data_flush(c);
>  
>  		/* Silence Coverity CWE-125 false positive */
>  		tcp4_l2_buf_used = tcp6_l2_buf_used = 0;
> @@ -2195,7 +2195,7 @@ static int tcp_data_from_sock(struct ctx *c, struct tcp_tap_conn *conn)
>  
>  	if (!len) {
>  		if ((conn->events & (SOCK_FIN_RCVD | TAP_FIN_SENT)) == SOCK_FIN_RCVD) {
> -			if ((ret = tcp_send_flag(c, conn, FIN | ACK))) {
> +			if ((ret = tcp_buf_send_flag(c, conn, FIN | ACK))) {
>  				tcp_rst(c, conn);
>  				return ret;
>  			}
> @@ -2378,7 +2378,7 @@ static int tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn,
>  			   max_ack_seq, conn->seq_to_tap);
>  		conn->seq_ack_from_tap = max_ack_seq;
>  		conn->seq_to_tap = max_ack_seq;
> -		tcp_data_from_sock(c, conn);
> +		tcp_buf_data_from_sock(c, conn);
>  	}
>  
>  	if (!iov_i)
> @@ -2394,14 +2394,14 @@ eintr:
>  			 *   Then swiftly looked away and left.
>  			 */
>  			conn->seq_from_tap = seq_from_tap;
> -			tcp_send_flag(c, conn, ACK);
> +			tcp_buf_send_flag(c, conn, ACK);
>  		}
>  
>  		if (errno == EINTR)
>  			goto eintr;
>  
>  		if (errno == EAGAIN || errno == EWOULDBLOCK) {
> -			tcp_send_flag(c, conn, ACK_IF_NEEDED);
> +			tcp_buf_send_flag(c, conn, ACK_IF_NEEDED);
>  			return p->count - idx;
>  
>  		}
> @@ -2411,7 +2411,7 @@ eintr:
>  	if (n < (int)(seq_from_tap - conn->seq_from_tap)) {
>  		partial_send = 1;
>  		conn->seq_from_tap += n;
> -		tcp_send_flag(c, conn, ACK_IF_NEEDED);
> +		tcp_buf_send_flag(c, conn, ACK_IF_NEEDED);
>  	} else {
>  		conn->seq_from_tap += n;
>  	}
> @@ -2424,7 +2424,7 @@ out:
>  		 */
>  		if (conn->seq_dup_ack_approx != (conn->seq_from_tap & 0xff)) {
>  			conn->seq_dup_ack_approx = conn->seq_from_tap & 0xff;
> -			tcp_send_flag(c, conn, DUP_ACK);
> +			tcp_buf_send_flag(c, conn, DUP_ACK);
>  		}
>  		return p->count - idx;
>  	}
> @@ -2438,7 +2438,7 @@ out:
>  
>  		conn_event(c, conn, TAP_FIN_RCVD);
>  	} else {
> -		tcp_send_flag(c, conn, ACK_IF_NEEDED);
> +		tcp_buf_send_flag(c, conn, ACK_IF_NEEDED);
>  	}
>  
>  	return p->count - idx;
> @@ -2474,8 +2474,8 @@ static void tcp_conn_from_sock_finish(struct ctx *c, struct tcp_tap_conn *conn,
>  	/* The client might have sent data already, which we didn't
>  	 * dequeue waiting for SYN,ACK from tap -- check now.
>  	 */
> -	tcp_data_from_sock(c, conn);
> -	tcp_send_flag(c, conn, ACK);
> +	tcp_buf_data_from_sock(c, conn);
> +	tcp_buf_send_flag(c, conn, ACK);
>  }
>  
>  /**
> @@ -2555,7 +2555,7 @@ int tcp_tap_handler(struct ctx *c, uint8_t pif, int af,
>  			conn->seq_from_tap++;
>  
>  			shutdown(conn->sock, SHUT_WR);
> -			tcp_send_flag(c, conn, ACK);
> +			tcp_buf_send_flag(c, conn, ACK);
>  			conn_event(c, conn, SOCK_FIN_SENT);
>  
>  			return 1;
> @@ -2566,7 +2566,7 @@ int tcp_tap_handler(struct ctx *c, uint8_t pif, int af,
>  
>  		tcp_tap_window_update(conn, ntohs(th->window));
>  
> -		tcp_data_from_sock(c, conn);
> +		tcp_buf_data_from_sock(c, conn);
>  
>  		if (p->count - idx == 1)
>  			return 1;
> @@ -2596,7 +2596,7 @@ int tcp_tap_handler(struct ctx *c, uint8_t pif, int af,
>  	if ((conn->events & TAP_FIN_RCVD) && !(conn->events & SOCK_FIN_SENT)) {
>  		shutdown(conn->sock, SHUT_WR);
>  		conn_event(c, conn, SOCK_FIN_SENT);
> -		tcp_send_flag(c, conn, ACK);
> +		tcp_buf_send_flag(c, conn, ACK);
>  		ack_due = 0;
>  	}
>  
> @@ -2630,7 +2630,7 @@ static void tcp_connect_finish(struct ctx *c, struct tcp_tap_conn *conn)
>  		return;
>  	}
>  
> -	if (tcp_send_flag(c, conn, SYN | ACK))
> +	if (tcp_buf_send_flag(c, conn, SYN | ACK))
>  		return;
>  
>  	conn_event(c, conn, TAP_SYN_ACK_SENT);
> @@ -2698,7 +2698,7 @@ static void tcp_tap_conn_from_sock(struct ctx *c,
>  
>  	conn->wnd_from_tap = WINDOW_DEFAULT;
>  
> -	tcp_send_flag(c, conn, SYN);
> +	tcp_buf_send_flag(c, conn, SYN);
>  	conn_flag(c, conn, ACK_FROM_TAP_DUE);
>  
>  	tcp_get_sndbuf(conn);
> @@ -2762,7 +2762,7 @@ void tcp_timer_handler(struct ctx *c, union epoll_ref ref)
>  		return;
>  
>  	if (conn->flags & ACK_TO_TAP_DUE) {
> -		tcp_send_flag(c, conn, ACK_IF_NEEDED);
> +		tcp_buf_send_flag(c, conn, ACK_IF_NEEDED);
>  		tcp_timer_ctl(c, conn);
>  	} else if (conn->flags & ACK_FROM_TAP_DUE) {
>  		if (!(conn->events & ESTABLISHED)) {
> @@ -2778,7 +2778,7 @@ void tcp_timer_handler(struct ctx *c, union epoll_ref ref)
>  			flow_dbg(conn, "ACK timeout, retry");
>  			conn->retrans++;
>  			conn->seq_to_tap = conn->seq_ack_from_tap;
> -			tcp_data_from_sock(c, conn);
> +			tcp_buf_data_from_sock(c, conn);
>  			tcp_timer_ctl(c, conn);
>  		}
>  	} else {
> @@ -2833,7 +2833,7 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events)
>  			conn_event(c, conn, SOCK_FIN_RCVD);
>  
>  		if (events & EPOLLIN)
> -			tcp_data_from_sock(c, conn);
> +			tcp_buf_data_from_sock(c, conn);
>  
>  		if (events & EPOLLOUT)
>  			tcp_update_seqack_wnd(c, conn, 0, NULL);
> @@ -3058,10 +3058,10 @@ int tcp_init(struct ctx *c)
>  		tc_hash[b] = FLOW_SIDX_NONE;
>  
>  	if (c->ifi4)
> -		tcp_sock4_iov_init(c);
> +		tcp_buf_sock4_iov_init(c);
>  
>  	if (c->ifi6)
> -		tcp_sock6_iov_init(c);
> +		tcp_buf_sock6_iov_init(c);
>  
>  	memset(init_sock_pool4,		0xff,	sizeof(init_sock_pool4));
>  	memset(init_sock_pool6,		0xff,	sizeof(init_sock_pool6));
> diff --git a/tcp.h b/tcp.h
> index b9f546d31002..e7dbcfa2ddbd 100644
> --- a/tcp.h
> +++ b/tcp.h
> @@ -23,7 +23,7 @@ int tcp_init(struct ctx *c);
>  void tcp_timer(struct ctx *c, const struct timespec *now);
>  void tcp_defer_handler(struct ctx *c);
>  
> -void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s);
> +void tcp_buf_update_l2(const unsigned char *eth_d, const unsigned char *eth_s);
>  
>  /**
>   * union tcp_epoll_ref - epoll reference portion for TCP connections

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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