/*
* test-apps/data-client.c
*/
#include <sys/socket.h>
#include <netinet/in.h>
#include <byteswap.h>
#include <arpa/inet.h>
#include <strings.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include "dnbd2.h"
void print_usage(void);
ssize_t writen(int fd, const void *msg, size_t n);
ssize_t readn(int fd, void *msg, size_t n);
int dnbd2_data_request(dnbd2_server_t server,
dnbd2_data_request_t request,
dnbd2_data_reply_t *reply);
int main(int argc, char **argv)
{
if (argc != 6) {
print_usage();
return 0;
}
dnbd2_data_request_t request;
dnbd2_data_reply_t reply;
/* The time field is always echoed by the server.
This is an arbitrary value. */
request.time = 28481;
/* Read IP and Port */
dnbd2_server_t server;
if (!inet_aton(argv[1], (struct in_addr *) &(server.ip))) {
fprintf(stderr, "Invalid IP\n");
return -1;
}
if (sscanf(argv[2], "%hu", &(server.port)) != 1) {
fprintf(stderr, "Invalid Port\n");
return -1;
}
server.port = htons(server.port);
/* Read Volume-ID and Release-ID */
if (sscanf(argv[3], "%hu", &(request.vid)) != 1) {
fprintf(stderr, "Invalid Volume-ID\n");
return -1;
}
if (sscanf(argv[4], "%hu", &(request.rid)) != 1) {
fprintf(stderr, "Invalid Release-ID\n");
return -1;
}
/* Read command */
char str[16];
int cmd = 0;
if (sscanf(argv[5], "%s", str) == 1) {
if (!strcmp("getdata", str))
cmd = 1;
if (!strcmp("getsize", str))
cmd = 2;
if (!strcmp("getservers", str))
cmd = 3;
}
if (!cmd) {
fprintf(stderr, "Invalid CMD\n");
return -1;
}
/* Complete and issue request(s) */
int ret, i, rest;
off_t size, blocks;
switch (cmd) {
case 1:
/* Get Dataset size */
request.cmd = CMD_GET_SIZE;
ret = dnbd2_data_request(server, request, &reply);
if (ret == -1)
goto out_nosize;
size = reply.num;
/* size = blocks * DNBD2_BLOCK_SIZE + rest */
blocks = size / DNBD2_BLOCK_SIZE;
rest = size % DNBD2_BLOCK_SIZE;
/* Fetch "blocks * DNBD2_BLOCK_SIZE" bytes */
request.cmd = CMD_GET_BLOCK;
for (i=0 ; i<blocks ; i++) {
request.num = i * DNBD2_BLOCK_SIZE;
ret = dnbd2_data_request(server, request, &reply);
if (ret == -1)
goto out_nodata;
write(STDOUT_FILENO, reply.payload.data,
DNBD2_BLOCK_SIZE);
}
/* Fetch "rest" bytes */
if (rest != 0) {
request.num = i*DNBD2_BLOCK_SIZE;
ret = dnbd2_data_request(server, request, &reply);
if (ret == -1)
goto out_nodata;
write(STDOUT_FILENO, reply.payload.data, rest);
}
break;
case 2:
/* Get Dataset size */
request.cmd = CMD_GET_SIZE;
ret = dnbd2_data_request(server, request, &reply);
if (ret == -1)
goto out_nosize;
printf("Dataset Size = %lld\n", reply.num);
break;
case 3:
/* Get list of alternative servers */
request.cmd = CMD_GET_SERVERS;
ret = dnbd2_data_request(server, request, &reply);
if (ret == -1)
goto out_noservers;
if (reply.num == 0)
printf("No alternative servers.\n");
for (i=0 ; i<reply.num ; i++) {
dnbd2_server_t server;
struct in_addr addr;
memcpy(&server,
&reply.payload.server[i],
sizeof(dnbd2_server_t));
memcpy(&addr,
&server.ip,
sizeof(uint32_t));
printf("%s:%hu\n", inet_ntoa(addr), ntohs(server.port));
}
break;
}
return 0;
out_nodata:
fprintf(stderr, "Could not get data.\n");
return -1;
out_nosize:
fprintf(stderr, "Could not get Dataset size.\n");
return -1;
out_noservers:
fprintf(stderr, "Could not get list of alternative servers.\n");
return -1;
}
int dnbd2_data_request(dnbd2_server_t server,
dnbd2_data_request_t request,
dnbd2_data_reply_t *reply)
{
struct sockaddr_in server_addr;
bzero(&server_addr, sizeof(server_addr));
server_addr.sin_addr.s_addr = server.ip;
server_addr.sin_port = server.port;
server_addr.sin_family = AF_INET;
int sockfd = socket(PF_INET, SOCK_DGRAM, 0);
if (sockfd == -1) {
fprintf(stderr, "Could not create socket.\n");
return -1;
}
if (connect(sockfd, (struct sockaddr *) &server_addr,
sizeof(server_addr)) == -1) {
fprintf(stderr,"Could not connect UDP socket.");
return -1;
}
request.cmd = htons(request.cmd);
request.time = htons(request.time);
request.vid = htons(request.vid);
request.rid = htons(request.rid);
request.num = htonll(request.num);
/* Send request. */
ssize_t n = writen(sockfd, &request, sizeof(request));
if (n == -1) {
fprintf(stderr, "Error sending request.\n");
return -1;
}
if (n != sizeof(request)) {
fprintf(stderr, "Sent wrong request size.\n");
return -1;
}
/* Receive reply. */
n = readn(sockfd, reply, sizeof(*reply));
if (n == -1) {
fprintf(stderr, "Error receiving reply.\n");
return -1;
}
if (n != sizeof(*reply)) {
fprintf(stderr, "Got wrong reply size.\n");
return -1;
}
close(sockfd);
reply->cmd = ntohs(reply->cmd);
reply->time = ntohs(reply->time);
reply->vid = ntohs(reply->vid);
reply->rid = ntohs(reply->rid);
reply->num = ntohll(reply->num);
return 0;
}
ssize_t writen(int fd, const void *msg, size_t n) {
size_t nleft;
ssize_t nwritten;
const char *ptr;
ptr = msg;
nleft = n;
while (nleft > 0) {
if ((nwritten = write(fd, ptr, nleft)) <= 0) {
if (errno == EINTR)
nwritten = 0;
else
return -1;
}
nleft -= nwritten;
ptr += nwritten;
}
return (n);
}
ssize_t readn(int fd, void *msg, size_t n) {
size_t nleft;
ssize_t nread;
char *ptr;
ptr = msg;
nleft = n;
while (nleft > 0) {
if ((nread = read(fd, ptr, nleft)) < 0) {
if (errno == EINTR)
nread = 0;
else
return -1;
} else if (nread == 0) {
break;
}
nleft -= nread;
ptr += nread;
}
return n - nleft;
}
void print_usage(void) {
printf("usage: dnbd2-data IP Port Volume-ID Release-ID "
"(getsize|getdata|getservers)\n");
printf(" getsize: Print the Dataset's size.\n");
printf(" getdata: Write the Dataset's contents to stdout.\n");
printf(" getsize: Print the list of alternative Servers.\n");
}
