RDMA编程实践-SEND-RECEICVE原语应用

RDMA编程实践

本文描述了RDMA编程过程中的SEND-RECEIVE双边原语的代码实现。包含多个版本，1、client向server发送消息，server回复client收到消息(ACK)，然后两边断开连接。2、server端循环等待客户端建立连接，client发送一次消息后，双方断开连接。3、server端循环等待客户端建立连接，一旦建立，client端可以一直向server端发送消息，直到发送消息为disconnect，server和client断开链接，但是server此时仍然可以等待别的client发送消息。
代码基于代码基于send-receive样例实现。关于代码注释，可以参考代码解释：
Makefile文件、会编译当前目录下的所有.c文件：

.PHONY: all clean

CC := gcc
CFLAGS := -Wall -g
LDLIBS := -lrdmacm -libverbs -lpthread -g

SRCS := $(wildcard *.c)
APPS := $(SRCS:.c=)

all: $(APPS)

%: %.c
	$(CC) $(CFLAGS) $< -o $@ $(LDLIBS)

clean:
	rm -f $(APPS)

version1 客户端-服务端消息一次传递

在这个阶段，我们希望能实现下面这样一个场景。client与server端相连接，client端能够发送一条消息给server，server收到该条消息之后恢复一条消息给client端表示我已经确认收到。之后两者断开连接。

代码：

// client1.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <getopt.h>
#include <rdma/rdma_cma.h>
#include <rdma/rdma_verbs.h>

static const char *server = "10.10.10.1";
static const char *port = "7471";

static struct rdma_cm_id *id;
static struct ibv_mr *mr, *send_mr;
static int send_flags;
static uint8_t send_msg[16];
static uint8_t recv_msg[16];

static int run(void)
{
   
   
	struct rdma_addrinfo hints, *res;
	struct ibv_qp_init_attr attr;
	struct ibv_wc wc;
	int ret;

	memset(&hints, 0, sizeof hints);
	hints.ai_port_space = RDMA_PS_TCP;
	ret = rdma_getaddrinfo(server, port, &hints, &res);
	if (ret) {
   
   
		printf("rdma_getaddrinfo: %s\n", gai_strerror(ret));
		goto out;
	}

	memset(&attr, 0, sizeof attr);
	attr.cap.max_send_wr = attr.cap.max_recv_wr = 1;
	attr.cap.max_send_sge = attr.cap.max_recv_sge = 1;
	attr.cap.max_inline_data = 16;
	attr.qp_context = id;
	attr.sq_sig_all = 1;
	ret = rdma_create_ep(&id, res, NULL, &attr);
	// Check to see if we got inline data allowed or not
	if (attr.cap.max_inline_data >= 16)
		send_flags = IBV_SEND_INLINE;
	else
		printf("rdma_client: device doesn't support IBV_SEND_INLINE, "
		       "using sge sends\n");

	if (ret) {
   
   
		perror("rdma_create_ep");
		goto out_free_addrinfo;
	}

	mr = rdma_reg_msgs(id, recv_msg, 16);
	if (!mr) {
   
   
		perror("rdma_reg_msgs for recv_msg");
		ret = -1;
		goto out_destroy_ep;
	}
	if ((send_flags & IBV_SEND_INLINE) == 0) {
   
   
		send_mr = rdma_reg_msgs(id, send_msg, 16);
		if (!send_mr) {
   
   
			perror("rdma_reg_msgs for send_msg");
			ret = -1;
			goto out_dereg_recv;
		}
	}

	ret = rdma_post_recv(id, NULL, recv_msg, 16, mr);
	if (ret) {
   
   
		perror("rdma_post_recv");
		goto out_dereg_send;
	}

	ret = rdma_connect(id, NULL);
	if (ret) {
   
   
		perror("rdma_connect");
		goto out_dereg_send;
	}


	printf("client send: %s\n", (char *)send_msg);
	ret = rdma_post_send(id, NULL, send_msg, 16, send_mr, send_flags);
	if (ret) {
   
   
		perror("rdma_post_send");
		goto out_disconnect;
	}

	while ((ret = rdma_get_send_comp(id, &wc)) == 0);
	if (ret < 0) {
   
   
		perror("rdma_get_send_comp");
		goto out_disconnect;
	}

	while ((ret = rdma_get_recv_comp(id, &wc)) == 0);
	if (ret < 0)
		perror("rdma_get_recv_comp");
	else
		ret = 0;
	
	printf("client received: %s\n", (char *) recv_msg);

out_disconnect:
	rdma_disconnect(id);
out_dereg_send:
	if ((send_flags & IBV_SEND_INLINE) == 0)
		rdma_dereg_mr(send_mr);
out_dereg_recv:
	rdma_dereg_mr(mr);
out_destroy_ep:
	rdma_destroy_ep(id);
out_free_addrinfo:
	rdma_freeaddrinfo(res);
out:
	return ret;
}

int main(int argc, char **argv)
{
   
   
	int ret;

	char *s = "hello world";
	// printf("client send: %s\n", s);
	memcpy(send_msg, s , strlen(s));

	printf("rdma_client: start\n");
	ret = run();
	printf("rdma_client: end %d\n", ret);
	return ret;
}

server端代码

// server1.c
/*
 * Copyright (c) 2005-2009 Intel Corporation.  All rights reserved.
 *
 * This software is available to you under the OpenIB.org BSD license
 * below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AWV
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <getopt.h>
#include <netdb.h>
#include <rdma/rdma_cma.h>
#include <rdma/rdma_verbs.h>

static const char *server = "0.0.0.0";
static const char *port = "7471";

static struct rdma_cm_id *listen_id, *id;
static struct ibv_mr *mr, *send_mr;
static int send_flags;
static uint8_t send_msg[16];
static uint8_t recv_msg[16];

static int run(void)
{
   
   
	struct rdma_addrinfo hints, *res;
	struct ibv_qp_init_attr init_attr;
	struct ibv_qp_attr qp_attr;
	struct ibv_wc wc;