static void
handle_oack_transmit(tftp_client_state_t *state)
{
int len;
len = snprintf(state->block_buffer + 2, sizeof(TFTP_OPT_BLKSIZE) + 1, "%s", TFTP_OPT_BLKSIZE);
len += snprintf(state->block_buffer + len + 3, 5 + 1, "%u", state->opt_blocksize);
state->block_buffer_size = 2 + len + 2;
send_oack(state->client, state->block_buffer, state->block_buffer_size);
}
/*
* WRQ - receive a file from the client
*/
void
tftp_wrq(int peer, char *recvbuffer, ssize_t size)
{
char *cp;
int has_options = 0, ecode;
char *filename, *mode;
char fnbuf[PATH_MAX];
cp = parse_header(peer, recvbuffer, size, &filename, &mode);
size -= (cp - recvbuffer) + 1;
strlcpy(fnbuf, filename, sizeof(fnbuf));
reduce_path(fnbuf);
filename = fnbuf;
if (size > 0) {
if (options_rfc_enabled)
has_options = !parse_options(peer, cp, size);
else
tftp_log(LOG_INFO, "Options found but not enabled");
}
ecode = validate_access(peer, &filename, WRQ);
if (ecode == 0) {
if (has_options)
send_oack(peer);
else
send_ack(peer, 0);
}
if (logging) {
tftp_log(LOG_INFO, "%s: write request for %s: %s", peername,
filename, errtomsg(ecode));
}
if (ecode) {
send_error(peer, ecode);
exit(1);
}
tftp_recvfile(peer, mode);
exit(0);
}
/******************************************************************************
Start obsluhy klienta
Inspirace (vytvoreni socketu, bind):
http://beej.us/guide/bgnet/output/html/multipage/clientserver.html#datagram
*******************************************************************************/
int Client::start(Opt *options, struct sockaddr_storage client_addr, int index, char *buf, int numbytes, int mtu)
{
// Generovani nahodneho cisla pro port, na kterem bude klient obsluhovan
srand (getpid());
int port = rand() % MAX_PORT + MIN_PORT;
client_port = to_string(port);
service_ip = options->address_at(index);
int sockfd;
struct addrinfo hints, *servinfo, *p;
int rv;
socklen_t addr_len;
char s[INET6_ADDRSTRLEN];
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
signal(SIGINT, client_signal_reaction); // Registrace funkce pro odchyt signalu
if ((rv = getaddrinfo(service_ip.c_str(), client_port.c_str(), &hints, &servinfo)) != 0)
{
cerr << "Error - Service " << service_ip << ", " << client_port << gai_strerror(rv) << endl;
return EXIT_FAILURE;
}
for(p = servinfo; p != NULL; p = p->ai_next)
{
if ((sockfd = socket(p->ai_family, p->ai_socktype,
p->ai_protocol)) == -1)
{
continue;
}
if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1)
{
close(sockfd);
continue;
}
break;
}
if (p == NULL)
{
cerr << "Error - Service " << service_ip << ", " << client_port << " - failed to bind socket" << endl;
return EXIT_FAILURE;
}
freeaddrinfo(servinfo);
client_socket = sockfd; // Ulozim si deskr. socketu
// Nastavi se vychozi timeout socketu
if((set_socket_timeout(options, IMPLICIT_TIMEOUT)) == SET_FAILED) return EXIT_FAILURE;
// ulozim si klientovu IP pro potreby vypisu informacnich hlasek
string client_ip = inet_ntop(client_addr.ss_family, get_in_addr((struct sockaddr *)&client_addr), s, sizeof s);
mtu_size = mtu; // Ulozim si MTU
// Cinnost obsluhy serveru
string err_msg;
unsigned int data_counter = 0; // Pocitadlo dat
unsigned int block_counter = 0; // Pocitadlo bloku
int data_len; // Pocet odeslanych B
int mode; // Mod prenosu
int tryouts = 0; // Pocet pokusu o znovu navazani komunikace
bool reading_data = false; // Flag cteni dat
bool writing_data = false; // Flag zapisu dat
int ack; // Cislo potvrzeneho bloku
int type; // Typ paketu
int file_status; // Info o uspesnosti operace se souborem
int bytes_write; // Pocet zapsanych bajtu
int block_num; // Cislo bloku
int recv_status; // Pocet prijatych B pri volani funkce recvfrom()
char *file_buf; // Buffer pro nacitani dat ze souboru
int file_buf_size;// Velikost bufferu
File *f = new File(); // Nova instance objektu pro praci se soubory
while(1)
{// Smycka obsluhy klienta
if(writing_data == true) type = packet_type(file_buf); // buffer na heapu
else type = packet_type(buf); // buffer na zasobniku
switch(type)
{// Podle typu paketu se provadi dana operace
case RRQ:
{// Zadost o cteni
get_filename(buf); // ukladani jmena souboru
// Zjisti se mod prenosu
mode = transfer_mode(buf);
if(mode == UNKNOWN_MODE)
{// neznamy mod
err_msg = "Unknown mode";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
cout << current_time() << client_ip << " Unknown mode, operation aborted" << endl;
clean_sources(f, sockfd);
return 1;
}
else if(mode == NETASCII)
{
cout << current_time() + client_ip + " Requested READ of " << filename << " [netascii]"<< endl;
}
else if(mode == OCTET)
{
cout << current_time() + client_ip + " Requested READ of " << filename << " [octet]"<< endl;
}
// Otevre se soubor pro cteni
file_status = f->open(filename, options->working_path(), FILE_IN, mode_tr);
if(file_status == NOT_FOUND)
{// Soubor nebyl nalezen
err_msg = "File not found";
send_error(sockfd, client_addr, err_msg, ERROR_NF);
cout << current_time() + client_ip + " File " << filename << " not found, operation aborted" << endl;
clean_sources(f, sockfd);
return 1;
}
else if(file_status == PERM_DEN)
{// Nedostatecne opravneni
err_msg = "Permission denided";
send_error(sockfd, client_addr, err_msg, ERROR_AV);
cout << current_time() << client_ip << " Permission denided, operation aborted" << endl;
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
// Zjisti se pritomnost rozsireni
if(opt_extension(buf, numbytes, options, f) == EXTENSION)
{// request obsahuje options
send_oack(sockfd, client_addr);
reading_data = true;
// Alokace bufferu pro nacitani souboru
if(block_size.used == true)
{// byla specifikovana velikost bloku
file_buf = new char[block_size.value + 1];
file_buf_size = block_size.value + 1;
if(f->get_file_size() > MAX_BLOCK_COUNT * block_size.value)
{// Soubor je prilis velky na prenos pres tftp
err_msg = "File is too large to send";
send_error(sockfd, client_addr, err_msg, ERROR_DF);
cout << current_time() + client_ip + " File is too large to send. Operation aborted\n";
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
}
else
{// mezi parametry nebyla velikost bloku, uvazuje se standardni
file_buf = new char[STANDARD_BLOCK + 1];
file_buf_size = STANDARD_BLOCK + 1;
}
}
else
{// bez parametru, posilani prvnich dat
if(f->get_file_size() > MAX_BLOCK_COUNT * STANDARD_BLOCK)
{// Soubor je prilis velky na prenos pres tftp
err_msg = "File is too large to send";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
cout << current_time() + client_ip + " File is too large to send. Operation aborted\n";
clean_sources(f, sockfd);
return 1;
}
// Alokace bufferu pro nacitani souboru - standardni velikost
file_buf = new char[STANDARD_BLOCK + 1];
reading_data = true;
cout << current_time() + client_ip + " Sending DATA\n";
// poslou se prvni data
data_len = send_data(sockfd, client_addr, 1, STANDARD_BLOCK, f, file_buf);
data_counter += data_len;
if(data_len < STANDARD_BLOCK)
{// Prvni blok je zaroven i posledni, tim konci cinnost
reading_data = false;
}
}
break;
}
case WRQ:
{// Zadost o zapis
get_filename(buf); // ulozim jmeno souboru
// Zjistim mod prenosu
mode = transfer_mode(buf);
if(mode == UNKNOWN_MODE)
{// neznamy mod
err_msg = "Unknown transfer mode";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
break;
}
else if(mode == NETASCII)
{
cout << current_time() << client_ip << " Requested WRITE of " << filename << " [netascii]" << endl;
}
else if(mode == OCTET)
{
cout << current_time() << client_ip << " Requested WRITE of " << filename << " [octet]" << endl;
}
// Otevre se soubor pro zapis
if(mode == OCTET)
{
file_status = f->open(filename, options->working_path(), FILE_OUT, OCTET);
}
else if(mode == NETASCII)
{
file_status = f->open(filename, options->working_path(), FILE_OUT, NETASCII);
}
if(file_status == FILE_EXISTS)
{// Soubor j*z existuje
err_msg = "File already exists";
send_error(sockfd, client_addr, err_msg, ERROR_AE);
cout << current_time() << client_ip << " File " << filename << " already exists, operation aborted" << endl;
clean_sources(f, sockfd);
return 1;
}
else if(file_status == CANNOT_OPEN)
{// Nelze otevrit
err_msg = "Cannot open file for writing";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
cout << current_time() << client_ip << " Cannot opet file " << filename << " for writing, operation aborted" << endl;
clean_sources(f, sockfd);
return 1;
}
// Zjisti se rozsireni
if(opt_extension(buf, numbytes, options, f) == EXTENSION)
{// request obsahuje options
send_oack(sockfd, client_addr);
// Alokace bufferu pro nacitani souboru
if(block_size.used == true)
{// byla specifikovana velikost bloku
file_buf = new char[block_size.value + 10];
file_buf_size = block_size.value + 10;
}
else
{// mezi parametry nebyla velikost bloku, uvazuje se standardni
file_buf = new char[STANDARD_BLOCK + 10];
file_buf_size = STANDARD_BLOCK + 10;
}
writing_data = true;
cout << current_time() + client_ip + " Receiving DATA\n";
}
else
{// Bez rozsireni, zasle se ack 0
send_ack(sockfd, client_addr, 0);
// Alokace bufferu pro zapis souboru - standardni velikost
file_buf = new char[STANDARD_BLOCK + 10];
file_buf_size = STANDARD_BLOCK + 10;
writing_data = true;
cout << current_time() + client_ip + " Receiving DATA\n";
}
break;
}
case DATA:
{// Datovy paket od klienta
if(writing_data == true)
{// Probiha prenos
block_num = ack_number(file_buf); // zjisti se cislo bloku
if((block_counter + 1) != block_num)
{// Prisel blok, ktery nenavazuje na predchozi
err_msg = "Error while file transfer";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
break;
}
int actual_block;
if(block_size.used == true)
{// Pouziva se nestandardni velikost bloku
actual_block = block_size.value;
bytes_write = recv_data(file_buf, numbytes, actual_block, f); // zapisou se data
}
else
{// Standardni velikost bloku
actual_block = STANDARD_BLOCK;
bytes_write = recv_data(file_buf, numbytes, actual_block, f); // zapisou se data
}
if(bytes_write >= 0)
{// Zapis byl uspesny, potvrdi se klientovi
send_ack(sockfd, client_addr, block_num);
block_counter++; // zvetsi se pocitadlo ulozenych bloku
data_counter += bytes_write; // pricte se pocet ulozenych dat k pocitadlu
if((numbytes - 4) < actual_block)
{// dat bylo min nez je velikost bloku
writing_data = false;
f->close_file(FILE_OUT); // uzavre se soubor pro zapis
cout << current_time() << client_ip << " File " << filename << " has been stored [" << data_counter << " B, " << block_counter << " blocks]" << endl;
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
}
else if(bytes_write == READ_ERR)
{// Zapis nebyl uspesny
err_msg = "Error while writing to file";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
}
break;
}
case ACK:
{// Potvrzeni od klienta, ze obdrzel konkretni datovy paket
ack = ack_number(buf);
if(ack == 0) cout << current_time() + client_ip + " Sending DATA\n";
if(reading_data == true)
{// prenos jeste nebyl dokoncen
if(block_size.used == true)
{// Pouziva se nestandardni velikost bloku
data_len = send_data(sockfd, client_addr, ack + 1, block_size.value, f, file_buf);
if(data_len == SEND_FAIL)
{// Chyba pri odesilani
cerr << current_time() << client_ip << " Error in sendto, operation aborted" << endl;
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
else if(data_len < block_size.value) reading_data = false;
}
else
{// Standardni velikost bloku
data_len = send_data(sockfd, client_addr, ack + 1, STANDARD_BLOCK, f, file_buf);
if(data_len == SEND_FAIL)
{// Chyba pri odesilani
cerr << current_time() << client_ip << " Error in sendto, operation aborted" << endl;
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
else if(data_len < STANDARD_BLOCK) reading_data = false;
}
data_counter += data_len;
}
else
{// Prenos byl dokoncen
cout << current_time() << client_ip << " File " << filename << " has been sent [" << data_counter << " B, " << ack << " blocks]\n";
clean_sources(f, sockfd);
return EXIT_SUCCESS;
}
break;
}
case ERR:
{// Error paket
int err;
if(reading_data == true)
{// Klient poslal error pri cteni dat
err = recv_error(buf);
switch(err)
{
case ERROR_UN:
{// Unknown transfer ID
f->close_file(FILE_IN);
cout << current_time() << client_ip << " Client aborted file read (transport error)" << endl;
return EXIT_FAILURE;
}
case ERROR_DF:
{// Disk full
f->close_file(FILE_IN);
cout << current_time() << client_ip << " Client aborted file read (too large)" << endl;
return EXIT_FAILURE;
}
case ERROR_ND:
{// Nedefinovana chyba
f->close_file(FILE_IN);
cout << current_time() << client_ip << " Client aborted file read (undefined error)" << endl;
return EXIT_FAILURE;
}
}
}
else if(writing_data == true)
{// Klient poslal error pri zapisu dat
err = recv_error(buf);
switch(err)
{
case ERROR_UN:
{// Unknown transfer ID
f->close_file(FILE_OUT);
cout << current_time() << client_ip << " Client aborted file write" << endl;
return EXIT_FAILURE;
}
case ERROR_ND:
{// Nedefinovana chyba
f->close_file(FILE_OUT);
cout << current_time() << client_ip << " Client aborted file read (undefined error)" << endl;
return EXIT_FAILURE;
}
}
}
break;
}
case UNKNOWN_OPCODE:
{// Neznamy opcode
err_msg = "Unknown request";
send_error(sockfd, client_addr, err_msg, ERROR_IL);
clean_sources(f, sockfd);
return EXIT_FAILURE;
}
}// konec switch(type)
if(writing_data == true)
{// Pokud probiha zapis, pouziva se vetsi buffer alokovany na halde
recv_status = recv_packet(sockfd, client_addr, file_buf, file_buf_size);
}
else
{// Pri cteni staci mensi velikost na zasobniku
recv_status = recv_packet(sockfd, client_addr, buf, BUFSIZE);
}
if(recv_status == TIMEOUT_ELAPSED)
{// Vyprsel cas cekani, probehne 3x pokus o znovu navazani komunikace
tryouts++;
if(tryouts == 3)
{// Probehly tri pokusy o znovu navazani komunikace
cout << current_time() << client_ip << " Timeout elapsed, operation aborted" << endl;
clean_sources(f, sockfd);
return 1;
}
else
{// Probehne pokus
cout << current_time() << client_ip << " Timeout elapsed, retrying..." << endl;
}
}
else
{// Byl normalne prijat paket
numbytes = recv_status;
tryouts = 0; // Vynuluje se pocitadlo neuspesnych pokusu
}
}
}
PROCESS_THREAD(tftpd_process, ev, data)
{
static struct etimer t;
static tftp_header *h;
static int len, block, ack;
static int tries;
static int fd = -1;
#if WITH_EXEC
static char *elf_err;
#endif
PROCESS_BEGIN();
etimer_set(&t, CLOCK_CONF_SECOND*3);
PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_TIMER);
setup_server();
#if WITH_EXEC
elfloader_init();
#endif
print_local_addresses();
while(1) {
/* connection from client */
RECV_PACKET(h);
len = 0;
init_config();
if(h->op == uip_htons(TFTP_RRQ)) {
connect_back();
PRINTF("< rrq for %s\n", h->filename);
len += strlen(h->filename)+1;
if(strcmp("octet", h->filename+len)) {
send_error(EUNDEF, "only octet mode supported");
goto close_connection;
}
len += strlen(h->filename+len)+1; /* skip mode */
parse_opts(h->options+len, uip_datalen()-len-2);
if(config.to_ack & OACK_ERROR) {
send_error(EOPTNEG, "");
goto close_connection;
}
fd = cfs_open(h->filename, CFS_READ);
if(fd<0) {
send_error(ENOTFOUND, "");
goto close_connection;
}
block = 0; ack = 0;
tries = TFTP_MAXTRIES;
PRINTF("starting transfer...\n");
for(;;) {
if(send_oack())
len = config.blksize; /* XXX hack to prevent loop exit*/
else
len = send_data(fd, block+1);
if(len<0) {
send_error(EUNDEF, "read failed");
goto close_file;
}
RECV_PACKET_TIMEOUT(h,t);
if(ev == PROCESS_EVENT_TIMER) {
PRINTF("ack timed out, tries left: %d\n", tries);
if(--tries<=0) goto close_file;
continue;
}
if(h->op != uip_htons(TFTP_ACK)) {
send_error(EBADOP, "");
goto close_file;
}
config.to_ack = 0;
tries = TFTP_MAXTRIES;
ack = uip_htons(h->block_nr);
if(ack == block+1) block++;
if(len < config.blksize && ack == block) goto done;
}
}
else if(h->op == uip_htons(TFTP_WRQ)) {
connect_back();
PRINTF("< wrq for %s\n", h->filename);
len += strlen(h->filename)+1;
strncpy(config.filename, h->filename, sizeof(config.filename)-1);
if(strcmp("octet", h->filename+strlen(h->filename)+1)) {
send_error(EUNDEF, "only octet mode supported");
goto close_connection;
}
len += strlen(h->filename+len)+1; /* skip mode */
parse_opts(h->options+len, uip_datalen()-len-2);
if(config.to_ack & OACK_ERROR) {
send_error(EOPTNEG, "");
goto close_connection;
}
cfs_remove(h->filename);
fd = cfs_open(h->filename, CFS_WRITE);
if(fd<0) {
send_error(EACCESS, "");
goto close_connection;
}
block = 0; ack = 0;
tries = TFTP_MAXTRIES;
PRINTF("starting transfer...\n");
if(!send_oack())
send_ack(block);
for(;;) {
RECV_PACKET_TIMEOUT(h,t);
if(ev == PROCESS_EVENT_TIMER) {
PRINTF("data timed out, tries left: %d\n", tries);
if(--tries<=0) goto close_file;
len = config.blksize; /* XXX hack to prevent loop exit*/
goto resend_ack;
}
if(h->op != uip_htons(TFTP_DATA)) {
send_error(EBADOP, "");
goto close_file;
}
config.to_ack = 0;
tries = TFTP_MAXTRIES;
ack = uip_htons(h->block_nr);
if(ack != block+1) continue;
/* else */ block++;
len = recv_data(fd, block);
if(len<0) {
send_error(EUNDEF, "write failed");
goto close_file;
}
#if WITH_EXEC
if(len < config.blksize) {
if(config.exec) {
if(exec_file(config.filename, &elf_err) != 0) {
send_error(EUNDEF, elf_err);
goto close_file;
}
}
}
#endif
resend_ack:
if(!send_oack())
send_ack(block);
if(len < config.blksize) goto done;
}
}
done:
PRINTF("done.\n");
close_file:
if(fd>=0)
cfs_close(fd);
fd = -1;
close_connection:
if(client_conn)
uip_udp_remove(client_conn);
client_conn = 0;
PRINTF("connection closed.\n");
}
PROCESS_END();
}
/*
* RRQ - send a file to the client
*/
void
tftp_rrq(int peer, char *recvbuffer, ssize_t size)
{
char *cp;
int has_options = 0, ecode;
char *filename, *mode;
char fnbuf[PATH_MAX];
cp = parse_header(peer, recvbuffer, size, &filename, &mode);
size -= (cp - recvbuffer) + 1;
strcpy(fnbuf, filename);
reduce_path(fnbuf);
filename = fnbuf;
if (size > 0) {
if (options_rfc_enabled)
has_options = !parse_options(peer, cp, size);
else
tftp_log(LOG_INFO, "Options found but not enabled");
}
ecode = validate_access(peer, &filename, RRQ);
if (ecode == 0) {
if (has_options) {
int n;
char lrecvbuffer[MAXPKTSIZE];
struct tftphdr *rp = (struct tftphdr *)lrecvbuffer;
send_oack(peer);
n = receive_packet(peer, lrecvbuffer, MAXPKTSIZE,
NULL, timeoutpacket);
if (n < 0) {
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Aborting: %s",
rp_strerror(n));
return;
}
if (rp->th_opcode != ACK) {
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"Expected ACK, got %s on OACK",
packettype(rp->th_opcode));
return;
}
}
}
if (logging)
tftp_log(LOG_INFO, "%s: read request for %s: %s", peername,
filename, errtomsg(ecode));
if (ecode) {
/*
* Avoid storms of naks to a RRQ broadcast for a relative
* bootfile pathname from a diskless Sun.
*/
if (suppress_naks && *filename != '/' && ecode == ENOTFOUND)
exit(0);
send_error(peer, ecode);
exit(1);
}
tftp_xmitfile(peer, mode);
}
