extern int netlink_rcv(struct nl_handler *handler, struct nlmsg *answer)
{
int ret;
struct sockaddr_nl nladdr;
struct iovec iov = {
.iov_base = answer,
.iov_len = answer->nlmsghdr.nlmsg_len,
};
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
nladdr.nl_pid = 0;
nladdr.nl_groups = 0;
again:
ret = recvmsg(handler->fd, &msg, 0);
if (ret < 0) {
if (errno == EINTR)
goto again;
return -errno;
}
if (!ret)
return 0;
if (msg.msg_flags & MSG_TRUNC)
return -EMSGSIZE;
return ret;
}
extern int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg)
{
struct sockaddr_nl nladdr;
struct iovec iov = {
.iov_base = (void*)nlmsg,
.iov_len = nlmsg->nlmsghdr.nlmsg_len,
};
struct msghdr msg = {
.msg_name = &nladdr,
.msg_namelen = sizeof(nladdr),
.msg_iov = &iov,
.msg_iovlen = 1,
};
int ret;
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
nladdr.nl_pid = 0;
nladdr.nl_groups = 0;
ret = sendmsg(handler->fd, &msg, 0);
if (ret < 0) {
return -errno;
}
return ret;
}
#ifndef NLMSG_ERROR
#define NLMSG_ERROR 0x2
#endif
extern int netlink_transaction(struct nl_handler *handler,
struct nlmsg *request, struct nlmsg *answer)
{
int ret;
ret = netlink_send(handler, request);
if (ret < 0)
return ret;
ret = netlink_rcv(handler, answer);
if (ret < 0)
return ret;
if (answer->nlmsghdr.nlmsg_type == NLMSG_ERROR) {
struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(answer);
errno = -err->error;
if (errno)
perror("Error configuring kernel");
return -errno;
}
return 0;
}
extern int netlink_open(struct nl_handler *handler, int protocol)
{
socklen_t socklen;
int sndbuf = 32768;
int rcvbuf = 32768;
memset(handler, 0, sizeof(*handler));
handler->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
if (handler->fd < 0)
return -errno;
if (setsockopt(handler->fd, SOL_SOCKET, SO_SNDBUF,
&sndbuf, sizeof(sndbuf)) < 0)
return -errno;
if (setsockopt(handler->fd, SOL_SOCKET, SO_RCVBUF,
&rcvbuf,sizeof(rcvbuf)) < 0)
return -errno;
memset(&handler->local, 0, sizeof(handler->local));
handler->local.nl_family = AF_NETLINK;
handler->local.nl_groups = 0;
if (bind(handler->fd, (struct sockaddr*)&handler->local,
sizeof(handler->local)) < 0)
return -errno;
socklen = sizeof(handler->local);
if (getsockname(handler->fd, (struct sockaddr*)&handler->local,
&socklen) < 0)
return -errno;
if (socklen != sizeof(handler->local))
return -EINVAL;
if (handler->local.nl_family != AF_NETLINK)
return -EINVAL;
handler->seq = time(NULL);
return 0;
}
extern int netlink_close(struct nl_handler *handler)
{
close(handler->fd);
handler->fd = -1;
return 0;
}
extern int genetlink_rcv(struct genl_handler *handler, struct genlmsg *genlmsg)
{
return netlink_rcv(&handler->nlh, (struct nlmsg *)&genlmsg->nlmsghdr);
}
extern int rtnetlink_rcv(struct rtnl_handler *handler, struct rtnlmsg *rtnlmsg)
{
return netlink_rcv(&handler->nlh, (struct nlmsg *)&rtnlmsg->nlmsghdr);
}
int main(int argc, char *argv[])
{
int argslen, rc, option, i;
int callback = 0;
struct sigaction action;
/* checking for missing arguments */
if( argc < 2 )
{
rc=-EINVAL;
errno=EINVAL;
printf(
"Correct Syntax:./xhw3 job_type infile1 infile2...\n");
goto out;
}
task = malloc(sizeof(struct job));
if(task == NULL){
rc= -ENOMEM;
errno= ENOMEM;
goto out;
}
task->job_type = 0;
task->file_opt = 0;
task->priority = 0;
task->algo = 0;
/* getting all arguments */
while( ( option = getopt( argc, argv, "csprAEDORe:a:" ) ) != -1 )
{
switch(option)
{
case 'c' :
callback = 1;
break;
case 's' :
if(task->job_type != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->job_type = CHECKSUM;
break;
case 'D' :
if(task->job_type != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->job_type = DECRYPT;
break;
case 'E' :
if(task->job_type != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->job_type = ENCRYPT;
break;
case 'p' :
if(task->job_type != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->job_type = PRINT;
break;
case 'r' :
if(task->job_type != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->job_type = REMOVE;
break;
case 'A' :
if(task->job_type != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->job_type = REMOVEALL;
break;
case 'O' :
if(task->file_opt != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->file_opt = OVERWRITE;
break;
case 'R' :
if(task->file_opt != 0){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->file_opt = RENAME;
break;
case 'e' :
if((task->priority != 0) ||
atoi(optarg) > 3 ||
atoi(optarg) < 1){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->priority = atoi(optarg);
break;
case 'a' :
if((task->job_type != ENCRYPT &&
task->job_type != DECRYPT &&
task->job_type != CHECKSUM &&
task->job_type != 0) ||
atoi(optarg) > 2 ||
atoi(optarg) < 1){
rc=-EINVAL;
errno=EINVAL;
goto out_free;
}
task->algo = atoi(optarg);
break;
case '?' :
rc=-EINVAL;
errno=EINVAL;
perror("Error: Wrong flag(s) entered\nError");
goto out_free;
}
}
/* checking for missing files */
if ((argc - optind < 1) &&
(task->job_type != PRINT && task->job_type != REMOVEALL))
{
rc = -EINVAL;
errno = EINVAL;
printf("Error: Input filename(s) missing\n");
goto out_free;
}
if(task->job_type == 0)
task->job_type = CHECKSUM;
if(task->file_opt == 0)
task->file_opt = RENAME;
if(task->priority == 0)
task->priority = 3;
if(task->algo == 0)
task->algo = AES;
if(task->job_type != PRINT){
if(task->job_type == ENCRYPT || task->job_type == DECRYPT){
/* calculating nmuber of input files */
if(argc-optind-1 != 0){
/* setting key */
task->key = argv[argc-1];
task->infile_count = argc-optind-1;
}
else{
task->infile_count = argc-optind;
task->key = malloc(sizeof(char)*5);
strcat(task->key, "00000");
}
}
else
task->infile_count = argc-optind;
/* setting infiles */
task->infiles=malloc(sizeof(char*)*task->infile_count);
for(i=0;i<task->infile_count;i++)
{
task->infiles[i]=argv[optind+i];
}
}
/* setting pid */
task->pid = getpid();
void *dummy = task;
argslen = sizeof(*task);
/* system call */
rc = syscall(__NR_xjob, dummy, argslen);
/* waiting for callback */
if (task->job_type != PRINT &&
task->job_type != REMOVEALL &&
task->job_type != REMOVE &&
callback ==1){
netlink_rcv();
}
out_free:
/* deallocating memory */
if(task->infiles)
free(task->infiles);
out:
/* printing appropriate message */
if (rc >= 0){
printf("%d\n", rc);
}
else{
printf("Error Number: %d\n", errno);
perror("Error");
}
exit(rc);
}