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

[Andrew Vagin]

On Fri, Nov 22, 2013 at 05:20:37AM +0400, 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)

I'm not sure that a stateless approach is good here. First of all you
will need to connect and disconnect each time.

Can we create interface similar with dynamic linking loader (man
dlopen).

struct criu_handle *h;

h = criu_open()
criu_check(h);
...
criu_smth(h);
...
criu_close(h);

> +{
> +	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;
> +}
> -- 
> 1.8.1.2
> 
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