/**
* Open an existing bus
*
* @param bus Bus information to fill
* @param file The filename of the bus
* @param flags `BUS_RDONLY`, `BUS_WRONLY` or `BUS_RDWR`
* any negative value is used internally
* for telling the function to not actually
* opening the bus, but just to parse the file
* @return 0 on success, -1 on error
*/
int
bus_open(bus_t *bus, const char *file, int flags)
{
int saved_errno;
char *line = NULL;
size_t len = 0;
FILE *f;
bus->sem_id = -1;
bus->key_sem = -1;
bus->key_shm = -1;
bus->message = NULL;
f = fopen(file, "r");
t(getline(&line, &len, f));
t(bus->key_sem = (key_t)atoll(line));
free(line), line = NULL, len = 0;
t(getline(&line, &len, f));
t(bus->key_shm = (key_t)atoll(line));
free(line), line = NULL;
fclose(f);
if (flags >= 0) {
t(open_semaphores(bus));
t(open_shared_memory(bus, flags));
}
return 0;
fail:
saved_errno = errno;
free(line);
errno = saved_errno;
return -1;
}
int main(int argc, char** argv)
{
if (argc < 2) {
fprintf(stderr, "Too few arguments given to server.\n./server N\n");
exit(EXIT_FAILURE);
}
int server_id = atoi(argv[1]);
pdecryptf_t decrypt = choose_decryption(server_id);
char mq_name[13];
sprintf(mq_name, "/mq_server_%d", server_id);
mqd_t mq = open_msg_queue(mq_name);
Command cmd;
int ret = receive_command(mq, &cmd);
if (ret == -1)
exit(EXIT_FAILURE);
Command *command = &cmd;
mqd_t ret_mq;
while(strcmp(command->name, "exit") != 0) {
//open shared memory
char* shm_name = command->name;
int shm_size = command->dim;
int shm_fd;
void* mem = open_shared_memory(shm_name, shm_size, &shm_fd);
if (mem == NULL) {
exit(EXIT_FAILURE);
}
// get size of the message from the first
// integer in the shared memory
int dim_message;
memcpy(&dim_message, mem, sizeof(int));
// decrypt message
void* out = malloc(1000);
int decrypt_size = decrypt(mem+sizeof(int), dim_message, out);
// copy result back in shared memory
memcpy(mem, &decrypt_size, sizeof(int));
memcpy(mem + sizeof(int), out, decrypt_size);
// Close shared memory
close_shared_memory(mem, shm_size, shm_fd, shm_name);
// Send message back to gateway with self removed
int i;
for (i = 1; i < 17; i++)
command->crypt[i-1] = command->crypt[i];
ret_mq = open_msg_queue(MQ_GATEWAY);
ret = send_command(ret_mq, command);
if (ret == -1)
exit(EXIT_FAILURE);
mq_close(ret_mq);
// Get another message from the mq
ret = receive_command(mq, command);
if (ret == -1)
exit(EXIT_FAILURE);
}
mq_close(mq);
mq_close(ret_mq);
return 0;
}