/*
* Send an ACK packet (acknowledgement).
*/
int
send_ack(int fp, uint16_t block)
{
struct tftphdr *tp;
int size;
char buf[MAXPKTSIZE];
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Sending ACK for block %d", block);
DROPPACKETn("send_ack", 0);
tp = (struct tftphdr *)buf;
size = sizeof(buf) - 2;
tp->th_opcode = htons((u_short)ACK);
tp->th_block = htons((u_short)block);
size = 4;
if (sendto(fp, buf, size, 0,
(struct sockaddr *)&peer_sock, peer_sock.ss_len) != size) {
tftp_log(LOG_INFO, "send_ack: %s", strerror(errno));
return (1);
}
return (0);
}
/*
* Send an ERROR packet (error message).
* Error code passed in is one of the
* standard TFTP codes, or a UNIX errno
* offset by 100.
*/
void
send_error(int peer, int error)
{
struct tftphdr *tp;
int length;
struct errmsg *pe;
char buf[MAXPKTSIZE];
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Sending ERROR %d", error);
DROPPACKET("send_error");
tp = (struct tftphdr *)buf;
tp->th_opcode = htons((u_short)ERROR);
tp->th_code = htons((u_short)error);
for (pe = errmsgs; pe->e_code >= 0; pe++)
if (pe->e_code == error)
break;
if (pe->e_code < 0) {
pe->e_msg = strerror(error - 100);
tp->th_code = EUNDEF; /* set 'undef' errorcode */
}
strcpy(tp->th_msg, pe->e_msg);
length = strlen(pe->e_msg);
tp->th_msg[length] = '\0';
length += 5;
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Sending ERROR %d: %s", error, tp->th_msg);
if (sendto(peer, buf, length, 0,
(struct sockaddr *)&peer_sock, peer_sock.ss_len) != length)
tftp_log(LOG_ERR, "send_error: %s", strerror(errno));
}
static void
tftp_recvfile(int peer, const char *mode)
{
uint16_t block;
struct timeval now1, now2;
struct tftp_stats ts;
gettimeofday(&now1, NULL);
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Receiving file");
write_init(0, file, mode);
block = 0;
tftp_receive(peer, &block, &ts, NULL, 0);
write_close();
gettimeofday(&now2, NULL);
if (debug&DEBUG_SIMPLE) {
double f;
if (now1.tv_usec > now2.tv_usec) {
now2.tv_usec += 1000000;
now2.tv_sec--;
}
f = now2.tv_sec - now1.tv_sec +
(now2.tv_usec - now1.tv_usec) / 100000.0;
tftp_log(LOG_INFO,
"Download of %jd bytes in %d blocks completed after %0.1f seconds\n",
(intmax_t)ts.amount, block, f);
}
return;
}
static int
send_packet(int peer, uint16_t block, char *pkt, int size)
{
int i;
int t = 1;
for (i = 0; i < 12 ; i++) {
DROPPACKETn("send_packet", 0);
if (sendto(peer, pkt, size, 0, (struct sockaddr *)&peer_sock,
peer_sock.ss_len) == size) {
if (i)
tftp_log(LOG_ERR,
"%s block %d, attempt %d successful",
packettype(ntohs(((struct tftphdr *)
(pkt))->th_opcode)), block, i);
return (0);
}
tftp_log(LOG_ERR,
"%s block %d, attempt %d failed (Error %d: %s)",
packettype(ntohs(((struct tftphdr *)(pkt))->th_opcode)),
block, i, errno, strerror(errno));
sleep(t);
if (t < 32)
t <<= 1;
}
tftp_log(LOG_ERR, "send_packet: %s", strerror(errno));
return (1);
}
/*
* Send an RRQ packet (write request).
*/
int
send_rrq(int peer, char *filename, char *mode)
{
int n;
struct tftphdr *tp;
char *bp;
char buf[MAXPKTSIZE];
int size;
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Sending RRQ: filename: '%s', mode '%s'",
filename, mode
);
DROPPACKETn("send_rrq", 1);
tp = (struct tftphdr *)buf;
tp->th_opcode = htons((u_short)RRQ);
size = 2;
bp = tp->th_stuff;
strcpy(bp, filename);
bp += strlen(filename);
*bp = 0;
bp++;
size += strlen(filename) + 1;
strcpy(bp, mode);
bp += strlen(mode);
*bp = 0;
bp++;
size += strlen(mode) + 1;
if (options_rfc_enabled) {
options[OPT_TSIZE].o_request = strdup("0");
size += make_options(peer, bp, sizeof(buf) - size);
}
n = sendto(peer, buf, size, 0,
(struct sockaddr *)&peer_sock, peer_sock.ss_len);
if (n != size) {
tftp_log(LOG_ERR, "send_rrq: %d %s", n, strerror(errno));
return (1);
}
return (0);
}
int
read_close(void)
{
if (fclose(file) != 0) {
tftp_log(LOG_ERR, "fclose() failed: %s", strerror(errno));
return 1;
}
return 0;
}
static void
tftp_xmitfile(int peer, const char *mode)
{
uint16_t block;
time_t now;
struct tftp_stats ts;
now = time(NULL);
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Transmitting file");
read_init(0, file, mode);
block = 1;
tftp_send(peer, &block, &ts);
read_close();
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_INFO, "Sent %jd bytes in %jd seconds",
(intmax_t)ts.amount, (intmax_t)time(NULL) - now);
}
/*
* Send an OACK packet (option acknowledgement).
*/
int
send_oack(int peer)
{
struct tftphdr *tp;
int size, i, n;
char *bp;
char buf[MAXPKTSIZE];
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Sending OACK");
DROPPACKETn("send_oack", 0);
/*
* Send back an options acknowledgement (only the ones with
* a reply for)
*/
tp = (struct tftphdr *)buf;
bp = buf + 2;
size = sizeof(buf) - 2;
tp->th_opcode = htons((u_short)OACK);
for (i = 0; options[i].o_type != NULL; i++) {
if (options[i].o_reply != NULL) {
n = snprintf(bp, size, "%s%c%s", options[i].o_type,
0, options[i].o_reply);
bp += n+1;
size -= n+1;
if (size < 0) {
tftp_log(LOG_ERR, "oack: buffer overflow");
exit(1);
}
}
}
size = bp - buf;
if (sendto(peer, buf, size, 0,
(struct sockaddr *)&peer_sock, peer_sock.ss_len) != size) {
tftp_log(LOG_INFO, "send_oack: %s", strerror(errno));
return (1);
}
return (0);
}
static char *
parse_header(int peer, char *recvbuffer, ssize_t size,
char **filename, char **mode)
{
char *cp;
int i;
struct formats *pf;
*mode = NULL;
cp = recvbuffer;
i = get_field(peer, recvbuffer, size);
if (i >= PATH_MAX) {
tftp_log(LOG_ERR, "Bad option - filename too long");
send_error(peer, EBADOP);
exit(1);
}
*filename = recvbuffer;
tftp_log(LOG_INFO, "Filename: '%s'", *filename);
cp += i;
i = get_field(peer, cp, size);
*mode = cp;
cp += i;
/* Find the file transfer mode */
for (cp = *mode; *cp; cp++)
if (isupper(*cp))
*cp = tolower(*cp);
for (pf = formats; pf->f_mode; pf++)
if (strcmp(pf->f_mode, *mode) == 0)
break;
if (pf->f_mode == NULL) {
tftp_log(LOG_ERR,
"Bad option - Unknown transfer mode (%s)", *mode);
send_error(peer, EBADOP);
exit(1);
}
tftp_log(LOG_INFO, "Mode: '%s'", *mode);
return (cp + 1);
}
/*
* 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);
}
static size_t
convert_from_net(char *buffer, size_t count)
{
size_t i, n;
/*
* Convert all CR/LF to LF and all CR,NUL to CR
*/
n = 0;
for (i = 0; i < count; i++) {
if (gotcr == 0) {
convbuffer[n++] = buffer[i];
gotcr = (buffer[i] == '\r');
continue;
}
/* CR, NULL -> CR */
if (buffer[i] == '\0') {
gotcr = 0;
continue;
}
/* CR, LF -> LF */
if (buffer[i] == '\n') {
if (n == 0) {
if (ftell(file) != 0) {
fseek(file, -1, SEEK_END);
convbuffer[n++] = '\n';
} else {
/* This shouldn't happen */
tftp_log(LOG_ERR,
"Received LF as first character");
abort();
}
} else
convbuffer[n-1] = '\n';
gotcr = 0;
continue;
}
/* Everything else just accept as is */
convbuffer[n++] = buffer[i];
gotcr = (buffer[i] == '\r');
continue;
}
return fwrite(convbuffer, 1, n, file);
}
/* Get a field from a \0 separated string */
ssize_t
get_field(int peer, char *buffer, ssize_t size)
{
char *cp = buffer;
while (cp < buffer + size) {
if (*cp == '\0') break;
cp++;
}
if (*cp != '\0') {
tftp_log(LOG_ERR, "Bad option - no trailing \\0 found");
send_error(peer, EBADOP);
exit(1);
}
return (cp - buffer + 1);
}
int
write_init(int fd, FILE *f, const char *mode)
{
if (f == NULL) {
file = fdopen(fd, "w");
if (file == NULL) {
int en = errno;
tftp_log(LOG_ERR, "fdopen() failed: %s",
strerror(errno));
return en;
}
} else
file = f;
convert = !strcmp(mode, "netascii");
return 0;
}
/*
* Send a DATA packet
*/
int
send_data(int peer, uint16_t block, char *data, int size)
{
char buf[MAXPKTSIZE];
struct tftphdr *pkt;
int n;
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Sending DATA packet %d of %d bytes",
block, size);
DROPPACKETn("send_data", 0);
pkt = (struct tftphdr *)buf;
pkt->th_opcode = htons((u_short)DATA);
pkt->th_block = htons((u_short)block);
memcpy(pkt->th_data, data, size);
n = send_packet(peer, block, (char *)pkt, size + 4);
return (n);
}
int
receive_packet(int peer, char *data, int size, struct sockaddr_storage *from,
int thistimeout)
{
struct tftphdr *pkt;
struct sockaddr_storage from_local;
struct sockaddr_storage *pfrom;
socklen_t fromlen;
int n;
static int waiting;
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG,
"Waiting %d seconds for packet", timeoutpacket);
pkt = (struct tftphdr *)data;
waiting = 0;
signal(SIGALRM, timeout);
setjmp(timeoutbuf);
alarm(thistimeout);
if (waiting > 0) {
alarm(0);
return (RP_TIMEOUT);
}
if (waiting > 0) {
tftp_log(LOG_ERR, "receive_packet: timeout");
alarm(0);
return (RP_TIMEOUT);
}
waiting++;
pfrom = (from == NULL) ? &from_local : from;
fromlen = sizeof(*pfrom);
n = recvfrom(peer, data, size, 0, (struct sockaddr *)pfrom, &fromlen);
alarm(0);
DROPPACKETn("receive_packet", RP_TIMEOUT);
if (n < 0) {
tftp_log(LOG_ERR, "receive_packet: timeout");
return (RP_TIMEOUT);
}
alarm(0);
if (n < 0) {
/* No idea what could have happened if it isn't a timeout */
tftp_log(LOG_ERR, "receive_packet: %s", strerror(errno));
return (RP_RECVFROM);
}
if (n < 4) {
tftp_log(LOG_ERR,
"receive_packet: packet too small (%d bytes)", n);
return (RP_TOOSMALL);
}
pkt->th_opcode = ntohs((u_short)pkt->th_opcode);
if (pkt->th_opcode == DATA ||
pkt->th_opcode == ACK)
pkt->th_block = ntohs((u_short)pkt->th_block);
if (pkt->th_opcode == DATA && n > pktsize) {
tftp_log(LOG_ERR, "receive_packet: packet too big");
return (RP_TOOBIG);
}
if (((struct sockaddr_in *)(pfrom))->sin_addr.s_addr !=
((struct sockaddr_in *)(&peer_sock))->sin_addr.s_addr) {
tftp_log(LOG_ERR,
"receive_packet: received packet from wrong source");
return (RP_WRONGSOURCE);
}
if (pkt->th_opcode == ERROR) {
tftp_log(pkt->th_code == EUNDEF ? LOG_DEBUG : LOG_ERR,
"Got ERROR packet: %s", pkt->th_msg);
return (RP_ERROR);
}
if (debug&DEBUG_PACKETS)
tftp_log(LOG_DEBUG, "Received %d bytes in a %s packet",
n, packettype(pkt->th_opcode));
return n - 4;
}
int
main(int argc, char *argv[])
{
struct tftphdr *tp;
int peer;
socklen_t peerlen, len;
ssize_t n;
int ch;
char *chroot_dir = NULL;
struct passwd *nobody;
const char *chuser = "******";
char recvbuffer[MAXPKTSIZE];
int allow_ro = 1, allow_wo = 1;
tzset(); /* syslog in localtime */
acting_as_client = 0;
tftp_openlog("tftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
while ((ch = getopt(argc, argv, "cCd:F:lnoOp:s:u:U:wW")) != -1) {
switch (ch) {
case 'c':
ipchroot = 1;
break;
case 'C':
ipchroot = 2;
break;
case 'd':
if (atoi(optarg) != 0)
debug += atoi(optarg);
else
debug |= debug_finds(optarg);
break;
case 'F':
newfile_format = optarg;
break;
case 'l':
logging = 1;
break;
case 'n':
suppress_naks = 1;
break;
case 'o':
options_rfc_enabled = 0;
break;
case 'O':
options_extra_enabled = 0;
break;
case 'p':
packetdroppercentage = atoi(optarg);
tftp_log(LOG_INFO,
"Randomly dropping %d out of 100 packets",
packetdroppercentage);
break;
case 's':
chroot_dir = optarg;
break;
case 'u':
chuser = optarg;
break;
case 'U':
mask = strtol(optarg, NULL, 0);
break;
case 'w':
create_new = 1;
break;
case 'W':
create_new = 1;
increase_name = 1;
break;
default:
tftp_log(LOG_WARNING,
"ignoring unknown option -%c", ch);
}
}
if (optind < argc) {
struct dirlist *dirp;
/* Get list of directory prefixes. Skip relative pathnames. */
for (dirp = dirs; optind < argc && dirp < &dirs[MAXDIRS];
optind++) {
if (argv[optind][0] == '/') {
dirp->name = argv[optind];
dirp->len = strlen(dirp->name);
dirp++;
}
}
}
else if (chroot_dir) {
dirs->name = "/";
dirs->len = 1;
}
if (ipchroot > 0 && chroot_dir == NULL) {
tftp_log(LOG_ERR, "-c requires -s");
exit(1);
}
umask(mask);
{
int on = 1;
if (ioctl(0, FIONBIO, &on) < 0) {
tftp_log(LOG_ERR, "ioctl(FIONBIO): %s", strerror(errno));
exit(1);
}
}
/* Find out who we are talking to and what we are going to do */
peerlen = sizeof(peer_sock);
n = recvfrom(0, recvbuffer, MAXPKTSIZE, 0,
(struct sockaddr *)&peer_sock, &peerlen);
if (n < 0) {
tftp_log(LOG_ERR, "recvfrom: %s", strerror(errno));
exit(1);
}
getnameinfo((struct sockaddr *)&peer_sock, peer_sock.ss_len,
peername, sizeof(peername), NULL, 0, NI_NUMERICHOST);
/*
* Now that we have read the message out of the UDP
* socket, we fork and exit. Thus, inetd will go back
* to listening to the tftp port, and the next request
* to come in will start up a new instance of tftpd.
*
* We do this so that inetd can run tftpd in "wait" mode.
* The problem with tftpd running in "nowait" mode is that
* inetd may get one or more successful "selects" on the
* tftp port before we do our receive, so more than one
* instance of tftpd may be started up. Worse, if tftpd
* break before doing the above "recvfrom", inetd would
* spawn endless instances, clogging the system.
*/
{
int i, pid;
for (i = 1; i < 20; i++) {
pid = fork();
if (pid < 0) {
sleep(i);
/*
* flush out to most recently sent request.
*
* This may drop some request, but those
* will be resent by the clients when
* they timeout. The positive effect of
* this flush is to (try to) prevent more
* than one tftpd being started up to service
* a single request from a single client.
*/
peerlen = sizeof peer_sock;
i = recvfrom(0, recvbuffer, MAXPKTSIZE, 0,
(struct sockaddr *)&peer_sock, &peerlen);
if (i > 0) {
n = i;
}
} else {
break;
}
}
if (pid < 0) {
tftp_log(LOG_ERR, "fork: %s", strerror(errno));
exit(1);
} else if (pid != 0) {
exit(0);
}
}
/*
* See if the client is allowed to talk to me.
* (This needs to be done before the chroot())
*/
{
struct request_info req;
request_init(&req, RQ_CLIENT_ADDR, peername, 0);
request_set(&req, RQ_DAEMON, "tftpd", 0);
if (hosts_access(&req) == 0) {
if (debug&DEBUG_ACCESS)
tftp_log(LOG_WARNING,
"Access denied by 'tftpd' entry "
"in /etc/hosts.allow");
/*
* Full access might be disabled, but maybe the
* client is allowed to do read-only access.
*/
request_set(&req, RQ_DAEMON, "tftpd-ro", 0);
allow_ro = hosts_access(&req);
request_set(&req, RQ_DAEMON, "tftpd-wo", 0);
allow_wo = hosts_access(&req);
if (allow_ro == 0 && allow_wo == 0) {
tftp_log(LOG_WARNING,
"Unauthorized access from %s", peername);
exit(1);
}
if (debug&DEBUG_ACCESS) {
if (allow_ro)
tftp_log(LOG_WARNING,
"But allowed readonly access "
"via 'tftpd-ro' entry");
if (allow_wo)
tftp_log(LOG_WARNING,
"But allowed writeonly access "
"via 'tftpd-wo' entry");
}
} else
if (debug&DEBUG_ACCESS)
tftp_log(LOG_WARNING,
"Full access allowed"
"in /etc/hosts.allow");
}
/*
* Since we exit here, we should do that only after the above
* recvfrom to keep inetd from constantly forking should there
* be a problem. See the above comment about system clogging.
*/
if (chroot_dir) {
if (ipchroot > 0) {
char *tempchroot;
struct stat sb;
int statret;
struct sockaddr_storage ss;
char hbuf[NI_MAXHOST];
statret = -1;
memcpy(&ss, &peer_sock, peer_sock.ss_len);
unmappedaddr((struct sockaddr_in6 *)&ss);
getnameinfo((struct sockaddr *)&ss, ss.ss_len,
hbuf, sizeof(hbuf), NULL, 0,
NI_NUMERICHOST);
asprintf(&tempchroot, "%s/%s", chroot_dir, hbuf);
if (ipchroot == 2)
statret = stat(tempchroot, &sb);
if (ipchroot == 1 ||
(statret == 0 && (sb.st_mode & S_IFDIR)))
chroot_dir = tempchroot;
}
/* Must get this before chroot because /etc might go away */
if ((nobody = getpwnam(chuser)) == NULL) {
tftp_log(LOG_ERR, "%s: no such user", chuser);
exit(1);
}
if (chroot(chroot_dir)) {
tftp_log(LOG_ERR, "chroot: %s: %s",
chroot_dir, strerror(errno));
exit(1);
}
chdir("/");
setgroups(1, &nobody->pw_gid);
if (setuid(nobody->pw_uid) != 0) {
tftp_log(LOG_ERR, "setuid failed");
exit(1);
}
}
len = sizeof(me_sock);
if (getsockname(0, (struct sockaddr *)&me_sock, &len) == 0) {
switch (me_sock.ss_family) {
case AF_INET:
((struct sockaddr_in *)&me_sock)->sin_port = 0;
break;
case AF_INET6:
((struct sockaddr_in6 *)&me_sock)->sin6_port = 0;
break;
default:
/* unsupported */
break;
}
} else {
memset(&me_sock, 0, sizeof(me_sock));
me_sock.ss_family = peer_sock.ss_family;
me_sock.ss_len = peer_sock.ss_len;
}
close(0);
close(1);
peer = socket(peer_sock.ss_family, SOCK_DGRAM, 0);
if (peer < 0) {
tftp_log(LOG_ERR, "socket: %s", strerror(errno));
exit(1);
}
if (bind(peer, (struct sockaddr *)&me_sock, me_sock.ss_len) < 0) {
tftp_log(LOG_ERR, "bind: %s", strerror(errno));
exit(1);
}
tp = (struct tftphdr *)recvbuffer;
tp->th_opcode = ntohs(tp->th_opcode);
if (tp->th_opcode == RRQ) {
if (allow_ro)
tftp_rrq(peer, tp->th_stuff, n - 1);
else {
tftp_log(LOG_WARNING,
"%s read access denied", peername);
exit(1);
}
}
if (tp->th_opcode == WRQ) {
if (allow_wo)
tftp_wrq(peer, tp->th_stuff, n - 1);
else {
tftp_log(LOG_WARNING,
"%s write access denied", peername);
exit(1);
}
}
exit(1);
}
/*
* 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);
}
/*
* Send a file via the TFTP data session.
*/
void
tftp_send(int peer, uint16_t *block, struct tftp_stats *ts)
{
struct tftphdr *rp;
int size, n_data, n_ack, try;
uint16_t oldblock;
char sendbuffer[MAXPKTSIZE];
char recvbuffer[MAXPKTSIZE];
rp = (struct tftphdr *)recvbuffer;
*block = 1;
ts->amount = 0;
do {
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Sending block %d", *block);
size = read_file(sendbuffer, segsize);
if (size < 0) {
tftp_log(LOG_ERR, "read_file returned %d", size);
send_error(peer, errno + 100);
goto abort;
}
for (try = 0; ; try++) {
n_data = send_data(peer, *block, sendbuffer, size);
if (n_data > 0) {
if (try == maxtimeouts) {
tftp_log(LOG_ERR,
"Cannot send DATA packet #%d, "
"giving up", *block);
return;
}
tftp_log(LOG_ERR,
"Cannot send DATA packet #%d, trying again",
*block);
continue;
}
n_ack = receive_packet(peer, recvbuffer,
MAXPKTSIZE, NULL, timeoutpacket);
if (n_ack < 0) {
if (n_ack == RP_TIMEOUT) {
if (try == maxtimeouts) {
tftp_log(LOG_ERR,
"Timeout #%d send ACK %d "
"giving up", try, *block);
return;
}
tftp_log(LOG_WARNING,
"Timeout #%d on ACK %d",
try, *block);
continue;
}
/* Either read failure or ERROR packet */
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_ERR, "Aborting: %s",
rp_strerror(n_ack));
goto abort;
}
if (rp->th_opcode == ACK) {
ts->blocks++;
if (rp->th_block == *block) {
ts->amount += size;
break;
}
/* Re-synchronize with the other side */
(void) synchnet(peer);
if (rp->th_block == (*block - 1)) {
ts->retries++;
continue;
}
}
}
oldblock = *block;
(*block)++;
if (oldblock > *block) {
if (options[OPT_ROLLOVER].o_request == NULL) {
/*
* "rollover" option not specified in
* tftp client. Default to rolling block
* counter to 0.
*/
*block = 0;
} else {
*block = atoi(options[OPT_ROLLOVER].o_request);
}
ts->rollovers++;
}
gettimeofday(&(ts->tstop), NULL);
} while (size == segsize);
abort:
return;
}
/*
* Receive a file via the TFTP data session.
*
* - It could be that the first block has already arrived while
* trying to figure out if we were receiving options or not. In
* that case it is passed to this function.
*/
void
tftp_receive(int peer, uint16_t *block, struct tftp_stats *ts,
struct tftphdr *firstblock, size_t fb_size)
{
struct tftphdr *rp;
uint16_t oldblock;
int n_data, n_ack, writesize, i, retry;
char recvbuffer[MAXPKTSIZE];
ts->amount = 0;
if (firstblock != NULL) {
writesize = write_file(firstblock->th_data, fb_size);
ts->amount += writesize;
for (i = 0; ; i++) {
n_ack = send_ack(peer, *block);
if (n_ack > 0) {
if (i == maxtimeouts) {
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, "
"giving up", *block);
return;
}
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, trying again",
*block);
continue;
}
break;
}
if (fb_size != segsize) {
gettimeofday(&(ts->tstop), NULL);
return;
}
}
rp = (struct tftphdr *)recvbuffer;
do {
oldblock = *block;
(*block)++;
if (oldblock > *block) {
if (options[OPT_ROLLOVER].o_request == NULL) {
/*
* "rollover" option not specified in
* tftp client. Default to rolling block
* counter to 0.
*/
*block = 0;
} else {
*block = atoi(options[OPT_ROLLOVER].o_request);
}
ts->rollovers++;
}
for (retry = 0; ; retry++) {
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"Receiving DATA block %d", *block);
n_data = receive_packet(peer, recvbuffer,
MAXPKTSIZE, NULL, timeoutpacket);
if (n_data < 0) {
if (retry == maxtimeouts) {
tftp_log(LOG_ERR,
"Timeout #%d on DATA block %d, "
"giving up", retry, *block);
return;
}
if (n_data == RP_TIMEOUT) {
tftp_log(LOG_WARNING,
"Timeout #%d on DATA block %d",
retry, *block);
send_ack(peer, oldblock);
continue;
}
/* Either read failure or ERROR packet */
if (debug&DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Aborting: %s",
rp_strerror(n_data));
goto abort;
}
if (rp->th_opcode == DATA) {
ts->blocks++;
if (rp->th_block == *block)
break;
tftp_log(LOG_WARNING,
"Expected DATA block %d, got block %d",
*block, rp->th_block);
/* Re-synchronize with the other side */
(void) synchnet(peer);
if (rp->th_block == (*block-1)) {
tftp_log(LOG_INFO, "Trying to sync");
*block = oldblock;
ts->retries++;
goto send_ack; /* rexmit */
}
} else {
tftp_log(LOG_WARNING,
"Expected DATA block, got %s block",
packettype(rp->th_opcode));
}
}
if (n_data > 0) {
writesize = write_file(rp->th_data, n_data);
ts->amount += writesize;
if (writesize <= 0) {
tftp_log(LOG_ERR,
"write_file returned %d", writesize);
if (writesize < 0)
send_error(peer, errno + 100);
else
send_error(peer, ENOSPACE);
goto abort;
}
}
send_ack:
for (i = 0; ; i++) {
n_ack = send_ack(peer, *block);
if (n_ack > 0) {
if (i == maxtimeouts) {
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, "
"giving up", *block);
return;
}
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, trying again",
*block);
continue;
}
break;
}
gettimeofday(&(ts->tstop), NULL);
} while (n_data == segsize);
/* Don't do late packet management for the client implementation */
if (acting_as_client)
return;
for (i = 0; ; i++) {
n_data = receive_packet(peer, (char *)rp, pktsize,
NULL, timeoutpacket);
if (n_data <= 0)
break;
if (n_data > 0 &&
rp->th_opcode == DATA && /* and got a data block */
*block == rp->th_block) /* then my last ack was lost */
send_ack(peer, *block); /* resend final ack */
}
abort:
return;
}
/*
* Receive a file.
*/
void
recvfile(int peer, char *port, int fd, char *name, char *mode)
{
struct tftphdr *rp;
uint16_t block;
char recvbuffer[MAXPKTSIZE];
int n, i;
struct tftp_stats tftp_stats;
stats_init(&tftp_stats);
rp = (struct tftphdr *)recvbuffer;
if (port == NULL) {
struct servent *se;
se = getservbyname("tftp", "udp");
((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
} else
((struct sockaddr_in *)&peer_sock)->sin_port =
htons(atoi(port));
for (i = 0; i < 12; i++) {
struct sockaddr_storage from;
/* Tell the other side what we want to do */
if (debug&DEBUG_SIMPLE)
printf("Requesting %s\n", name);
n = send_rrq(peer, name, mode);
if (n > 0) {
printf("Cannot send RRQ packet\n");
return;
}
/*
* The first packet we receive has the new destination port
* we have to send the next packets to.
*/
n = receive_packet(peer, recvbuffer,
MAXPKTSIZE, &from, timeoutpacket);
/* We got something useful! */
if (n >= 0) {
((struct sockaddr_in *)&peer_sock)->sin_port =
((struct sockaddr_in *)&from)->sin_port;
break;
}
/* We should retry if this happens */
if (n == RP_TIMEOUT) {
printf("Try %d, didn't receive answer from remote.\n",
i + 1);
continue;
}
/* Otherwise it is a fatal error */
break;
}
if (i == 12) {
printf("Transfer timed out.\n");
return;
}
if (rp->th_opcode == ERROR) {
tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
return;
}
if (write_init(fd, NULL, mode) < 0) {
warn("write_init");
return;
}
/*
* If the first packet is an OACK packet instead of an DATA packet,
* handle it different.
*/
if (rp->th_opcode == OACK) {
if (!options_rfc_enabled) {
printf("Got OACK while options are not enabled!\n");
send_error(peer, EBADOP);
return;
}
parse_options(peer, rp->th_stuff, n + 2);
n = send_ack(peer, 0);
if (n > 0) {
printf("Cannot send ACK on OACK.\n");
return;
}
block = 0;
tftp_receive(peer, &block, &tftp_stats, NULL, 0);
} else {
block = 1;
tftp_receive(peer, &block, &tftp_stats, rp, n);
}
write_close();
if (tftp_stats.amount > 0)
printstats("Received", verbose, &tftp_stats);
return;
}