转自:

http://www.justwinit.cn/post/3960/

RPC是glibc提供的函数参数/返回值封装服务, 并将封装结果通过网络传到服务器.

RPC服务端首先要启动portmapper服务.

测试一个简单的RPC传输示例, 先定义一个模板文件test.x

program TESTPROG{

version VERSION{

int int_echo(int)=1;

int get_str_len(string)=2;

int add ( int, int ) = 3;

}=1;

}=30000;内含3个函数, 注意其中一个有2个参数.

然后可以用rpcgen生成一个Makefile:

rpcgen -a -N test.x

这会生成Makefile, 客户端和服务端的程序, 和函数示例.

我们手工修改一下Makefile

# This is a template Makefile generated by rpcgen

# Parameters

CLIENT = test_client

SERVER = test_server

SOURCES_CLNT.c =

SOURCES_CLNT.h =

SOURCES_SVC.c =

SOURCES_SVC.h =

SOURCES.x = test.x

TARGETS_SVC.c = test_svc.c test_server.c test_xdr.c

TARGETS_CLNT.c = test_clnt.c test_client.c test_xdr.c

TARGETS = test.h test_xdr.c test_clnt.c test_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 -pipe

LDLIBS += -lnsl

RPCGENFLAGS = -N

# 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)

修改test_server.c服务端的处理函数, 提供3种服务:

/*

* This is sample code generated by rpcgen.

* These are only templates and you can use them

* as a guideline for developing your own functions.

*/

#include "test.h"

int *

int_echo_1_svc(int arg1,  struct svc_req *rqstp)

{

static int  result;

//echo.

result=arg1;

printf("[RPC1] source=%d, echo=%d\n", arg1, result);

return &result;

}

int *

get_str_len_1_svc(char *arg1,  struct svc_req *rqstp)

{

static int  result;

//get strlen.

result=strlen(arg1);

printf("[PRC2] str=%s, len=%d\n", arg1, result);

return &result;

}

int *

add_1_svc(int arg1, int arg2,  struct svc_req *rqstp)

{

static int  result;

result=arg1+arg2;

printf("[RPC3] %d+%d=%d\n", arg1, arg2, result);

return &result;

}

客户端test_client.c, 调用这三种服务:

/*

* This is sample code generated by rpcgen.

* These are only templates and you can use them

* as a guideline for developing your own functions.

*/

#include "test.h"

void

testprog_1(char *host)

{

CLIENT *clnt;

int  *result_1;

int int_echo_1_arg1=55;

int  *result_2;

char *get_str_len_1_arg1="Hello, world";

int  *result_3;

int add_1_arg1=10;

int add_1_arg2=20;

clnt = clnt_create (host, TESTPROG, VERSION, "udp");

if (clnt == NULL) {

clnt_pcreateerror (host);

exit (1);

}

result_1 = int_echo_1(int_echo_1_arg1, clnt);

if (result_1 == (int *) NULL) {

clnt_perror (clnt, "call failed");

}

else

printf("[PRC1] echo %d, source %d\n", *result_1,

int_echo_1_arg1);

result_2 = get_str_len_1(get_str_len_1_arg1, clnt);

if (result_2 == (int *) NULL) {

clnt_perror (clnt, "call failed");

}

else

printf("[RPC2] return %d, should %d\n", *result_2,

strlen(get_str_len_1_arg1));

result_3 = add_1(add_1_arg1, add_1_arg2, clnt);

if (result_3 == (int *) NULL) {

clnt_perror (clnt, "call failed");

}

else

printf("[PRC3] %d+%d=%d\n", add_1_arg1, add_1_arg2,

*result_3);

clnt_destroy (clnt);

}OK, 可以调用make了.

生成可执行程序test_server和test_client.

我们启动./test_server, 用rpcinfo看看:

$rpcinfo -p 127.0.0.1

program vers proto port

100000 2 tcp 111 portmapper

30000 1 udp 36307

30000 1 tcp 34883

Bingo! 启动成功.

再开个终端, 尝试一下调用.

./test_client 127.0.0.1

[PRC1] echo 55, source 55

[RPC2] return 12, should 12

[PRC3] 10+20=30

正是我们期望的.

Add By：Jackxiang

make -f Makefile.test