[CRIU] [PATCH 3/3] lib: add criu_check() to libcriu

[Ruslan Kuprieiev]

On 22.11.2013 09:20, Pavel Emelyanov wrote:
> On 11/22/2013 05:20 AM, Ruslan Kuprieiev wrote:
>> Signed-off-by: Ruslan Kuprieiev <kupruser at gmail.com>
>> ---
>>   lib/criu.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 128 insertions(+)
>>
>> diff --git a/lib/criu.c b/lib/criu.c
>> index 2bd224e..f154a88 100644
>> --- a/lib/criu.c
>> +++ b/lib/criu.c
>> @@ -1,3 +1,131 @@
>>   #include "version.h"
>> +#include <sys/socket.h>
>> +#include <sys/un.h>
>> +#include <limits.h>
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <stdlib.h>
>> +
>> +#include "rpc.pb-c.h"
>> +
>> +#define MAX_MSG_SIZE 1024
>> +#define CR_DEFAULT_SERVICE_ADDRESS "/var/run/criu_service.socket"
>>   
>>   const char *criu_lib_version = CRIU_VERSION;
>> +
>> +static char *service_address = CR_DEFAULT_SERVICE_ADDRESS;
>> +
>> +void criu_set_service_address(char *path)
>> +{
>> +	if (path)
>> +		service_address = path;
>> +	else
>> +		service_address = CR_DEFAULT_SERVICE_ADDRESS;
>> +}
>> +
>> +static CriuResp *recv_resp(int socket_fd)
>> +{
>> +	unsigned char buf[MAX_MSG_SIZE];
>> +	int len;
>> +	CriuResp *msg = 0;
>> +
>> +	len = read(socket_fd, buf, MAX_MSG_SIZE);
>> +	if (len == -1) {
>> +		perror("Can't read response");
>> +		return NULL;
>> +	}
>> +
>> +	msg = criu_resp__unpack(NULL, len, buf);
>> +	if (!msg) {
>> +		perror("Failed unpacking response");
>> +		return NULL;
>> +	}
>> +
>> +	return msg;
>> +}
>> +
>> +static int send_req(int socket_fd, CriuReq *req)
>> +{
>> +	unsigned char buf[MAX_MSG_SIZE];
>> +	int len;
>> +
>> +	len = criu_req__get_packed_size(req);
>> +
>> +	if (criu_req__pack(req, buf) != len) {
>> +		perror("Failed packing request");
>> +		return -1;
>> +	}
>> +
>> +	if (write(socket_fd, buf, len)  == -1) {
>> +		perror("Can't send request");
>> +		return -1;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int criu_connect(void)
>> +{
>> +	int fd, ret;
>> +	struct sockaddr_un addr;
>> +	socklen_t addr_len;
>> +
>> +	fd = socket(AF_LOCAL, SOCK_SEQPACKET, 0);
>> +	if (fd < 0) {
>> +		perror("Can't create socket");
>> +		return -1;
>> +	}
>> +
>> +	memset(&addr, 0, sizeof(addr));
>> +	addr.sun_family = AF_LOCAL;
>> +
>> +	strcpy(addr.sun_path, service_address);
>> +
>> +	addr_len = strlen(addr.sun_path) + sizeof(addr.sun_family);
>> +
>> +	ret = connect(fd, (struct sockaddr *) &addr, addr_len);
>> +	if (ret < 0) {
>> +		perror("Can't connect to socket");
>> +		close(fd);
>> +	}
>> +
>> +	return fd;
>> +}
>> +
>> +int criu_check(void)
> Please, define a set of errors in lib.h and use them in
> criu_check().

Can you please explain how it should be done? Error must be returned or 
set as errno?

>
> Also provide criu_dump() and criu_restore() functions.

Sure. I'm going to add them by separate patches.

> i
>
>> +{
>> +	int fd;
>> +	int ret = -1;
>> +	CriuReq req	= CRIU_REQ__INIT;
>> +	CriuResp *resp	= NULL;
>> +
>> +	fd = criu_connect();
>> +	if (fd < 0) {
>> +		perror("Can't connect to criu");
>> +		return -1;
>> +	}
>> +
>> +	req.type	= CRIU_REQ_TYPE__CHECK;
>> +
>> +	if (send_req(fd, &req) < 0)
>> +		goto exit;
>> +
>> +	resp = recv_resp(fd);
>> +	if (!resp) {
>> +		perror("Can't receive response");
>> +		goto exit;
>> +	}
>> +
>> +	if (resp->type != CRIU_REQ_TYPE__CHECK) {
>> +		perror("Unexpected response type");
>> +		goto exit;
>> +	}
>> +
>> +	ret = resp->success ? 0 : -1;
>> +
>> +exit:
>> +	close(fd);
>> +	free(resp);
>> +
>> +	return ret;
>> +}
>>
>