Linux RPC远程调用示例

客户端给服务器端发送一个包含2给整数的字符串，服务器端发回他们的和。

1. radd.x

/* radd.x */
/* RPC declarations for add program */
/* http://zhoulifa.bokee.com/6129455.html */

/* ------------------------------------------------------------------
* RADDPROG -- remote program that provides Two Int Add
* ------------------------------------------------------------------ */
program RADDPROG  /* name of remote program ( not used ) */
{
    version RADDVERS  /* declaration of version ( see below ) */
    {
        int IntAdd ( string )     = 1;  /* first procedure in this program */
    } = 1;  /* definition of the program version */
} = 0x30090949;  /* remote program number ( must be unique ) */

上面代码的含义是，服务器端包含一个函数IntAdd，其参数为string，返回int。

2. 使用rpcgen生成所需文件

server端 

 rpcgen -Ss -o radd_srv_func.c radd.x

 client端 

 rpcgen -Sc -o radd_client.c radd.x 

 Makefile文件 

 rpcgen -Sm radd.x > Makefile

3. 修改radd_srv_func.c，添加函数功能

#include "radd.h"

int *
intadd_1_svc(char **argp, struct svc_req *rqstp)
{
	static int  result;

	/*
	 * insert server code here
	 */
	int num1, num2;
	sscanf(*argp, "%d %d", &num1, &num2);
	result = num1 + num2;

	return &result;
}

4. 修改radd_client.c



#include "radd.h"

void
raddprog_1(char *host)
{
	CLIENT *clnt;
	int  *result_1;
	char * intadd_1_arg;

#ifndef	DEBUG
	clnt = clnt_create (host, RADDPROG, RADDVERS, "udp");
	if (clnt == NULL) {
		clnt_pcreateerror (host);
		exit (1);
	}
#endif	/* DEBUG */
	char word[256];
	while(1) {
		printf("Please input two integers: ");
		fgets(word, 256, stdin);
		intadd_1_arg = word;
		result_1 = intadd_1(&intadd_1_arg, clnt);
		if (result_1 == (int *) NULL) {
			clnt_perror (clnt, "call failed");
		}
		printf("sum = %d\n", *result_1);
	}
#ifndef	DEBUG
	clnt_destroy (clnt);
#endif	 /* DEBUG */
}


int
main (int argc, char *argv[])
{
	char *host;

	if (argc < 2) {
		printf ("usage: %s server_host\n", argv[0]);
		exit (1);
	}
	host = argv[1];
	raddprog_1 (host);
exit (0);
}

5. 修改Makefile

# This is a template Makefile generated by rpcgen

# Parameters

CLIENT = radd_client
SERVER = radd_server

SOURCES_CLNT.c = 
SOURCES_CLNT.h = 
SOURCES_SVC.c = 
SOURCES_SVC.h = 
SOURCES.x = radd.x

TARGETS_SVC.c = radd_svc.c radd_srv_func.c
TARGETS_CLNT.c = radd_clnt.c  radd_client.c
TARGETS = radd.h  radd_clnt.c radd_svc.c

OBJECTS_CLNT = $(SOURCES_CLNT.c:%.c=%.o) $(TARGETS_CLNT.c:%.c=%.o)
OBJECTS_SVC = $(SOURCES_SVC.c:%.c=%.o) $(TARGETS_SVC.c:%.c=%.o)
# Compiler flags 

CFLAGS += -g 
LDLIBS += -lnsl
RPCGENFLAGS = 

# Targets 

all : $(CLIENT) $(SERVER)

$(TARGETS) : $(SOURCES.x) 
	rpcgen $(RPCGENFLAGS) $(SOURCES.x)

$(OBJECTS_CLNT) : $(SOURCES_CLNT.c) $(SOURCES_CLNT.h) $(TARGETS_CLNT.c) 

$(OBJECTS_SVC) : $(SOURCES_SVC.c) $(SOURCES_SVC.h) $(TARGETS_SVC.c) 

$(CLIENT) : $(OBJECTS_CLNT) 
	$(LINK.c) -o $(CLIENT) $(OBJECTS_CLNT) $(LDLIBS) 

$(SERVER) : $(OBJECTS_SVC) 
	$(LINK.c) -o $(SERVER) $(OBJECTS_SVC) $(LDLIBS)

 clean:
	 $(RM) core $(TARGETS) $(OBJECTS_CLNT) $(OBJECTS_SVC) $(CLIENT) $(SERVER)


主要是这三行

TARGETS_SVC.c = radd_svc.c radd_srv_func.c
TARGETS_CLNT.c = radd_clnt.c  radd_client.c
TARGETS = radd.h  radd_clnt.c radd_svc.c

6. make，然后即可运行生成的可执行文件

运行server端，需要安装portmap，并执行portmap start命令。(开启端口映射功能)
root@ubuntu:~/下载/RPC/add# ./radd_client 127.0.0.1
Please input two integers: 5 5
sum = 10
Please input two integers: 6 6
sum = 12