/*
* Send a nak packet (error message).
* Error code passed in is one of the
* standard TFTP codes, or a UNIX errno
* offset by 100.
*/
static void nak(int f, union sock_addr *peeraddr,
int error, const char *msg)
{
struct tftphdr *tp;
int length;
tp = (struct tftphdr *)ackbuf;
tp->th_opcode = htons((u_short) ERROR);
tp->th_code = htons((u_short) error);
if (error >= 100) {
/* This is a Unix errno+100 */
if (!msg)
msg = strerror(error - 100);
error = EUNDEF;
} else {
if ((unsigned)error >= ERR_CNT)
error = EUNDEF;
if (!msg)
msg = errmsgs[error];
}
tp->th_code = htons((u_short) error);
length = strlen(msg) + 1;
memcpy(tp->th_msg, msg, length);
length += 4; /* Add space for header */
if (trace)
tpacket("sent", tp, length);
if (sendto(f, ackbuf, length, 0, &(peeraddr->sa),
SOCKLEN(peeraddr)) != length)
perror("nak");
}
/*
* Send a nak packet (error message).
* Error code passed in is one of the
* standard TFTP codes, or a UNIX errno
* offset by 100.
*/
void
nak(int error)
{
register struct errmsg *pe;
register struct tftphdr *tp;
int length;
tp = (struct tftphdr *)ackbuf;
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;
}
strcpy(tp->th_msg, pe->e_msg);
length = strlen(pe->e_msg) + 4;
if (trace)
tpacket("sent", tp, length);
if (sendto(f, ackbuf, length, 0, (struct sockaddr *)&s_inn,
sizeof (s_inn)) != length)
perror("nak");
}
/*
* Send the requested file.
*/
int tftp_sendfile(int f, union sock_addr *peeraddr,
int fd, const char *name, const char *mode)
{
struct tftphdr *ap; /* data and ack packets */
struct tftphdr *dp;
int n;
volatile int is_request;
volatile u_short block;
volatile int size, convert;
volatile off_t amount;
union sock_addr from;
socklen_t fromlen;
FILE *file;
u_short ap_opcode, ap_block;
startclock(); /* start stat's clock */
dp = r_init(); /* reset fillbuf/read-ahead code */
ap = (struct tftphdr *)ackbuf;
convert = !strcmp(mode, "netascii");
file = fdopen(fd, convert ? "rt" : "rb");
block = 0;
is_request = 1; /* First packet is the actual WRQ */
amount = 0;
bsd_signal(SIGALRM, timer);
do {
if (is_request) {
size = makerequest(WRQ, name, dp, mode) - 4;
} else {
/* size = read(fd, dp->th_data, SEGSIZE); */
size = readit(file, &dp, convert);
if (size < 0) {
nak(f, peeraddr, errno + 100, NULL);
break;
}
dp->th_opcode = htons((u_short) DATA);
dp->th_block = htons((u_short) block);
}
timeout = 0;
(void)sigsetjmp(timeoutbuf, 1);
if (trace)
tpacket("sent", dp, size + 4);
n = sendto(f, dp, size + 4, 0,
&(peeraddr->sa), SOCKLEN(peeraddr));
if (n != size + 4) {
perror("tftp: sendto");
goto abort;
}
read_ahead(file, convert);
for (;;) {
alarm(rexmtval);
do {
fromlen = sizeof(from);
n = recvfrom(f, ackbuf, sizeof(ackbuf), 0,
&from.sa, &fromlen);
} while (n <= 0);
alarm(0);
if (n < 0) {
perror("tftp: recvfrom");
goto abort;
}
sa_set_port(peeraddr, SOCKPORT(&from)); /* added */
if (trace)
tpacket("received", ap, n);
/* should verify packet came from server */
ap_opcode = ntohs((u_short) ap->th_opcode);
ap_block = ntohs((u_short) ap->th_block);
if (ap_opcode == ERROR) {
printf("Error code %d: %s\n", ap_block, ap->th_msg);
goto abort;
}
if (ap_opcode == ACK) {
int j;
if (ap_block == block) {
break;
}
/* On an error, try to synchronize
* both sides.
*/
j = synchnet(f);
if (j && trace) {
printf("discarded %d packets\n", j);
}
/*
* RFC1129/RFC1350: We MUST NOT re-send the DATA
* packet in response to an invalid ACK. Doing so
* would cause the Sorcerer's Apprentice bug.
*/
}
}
if (!is_request)
amount += size;
is_request = 0;
block++;
} while (size == SEGSIZE || block == 1);
abort:
fclose(file);
stopclock();
//if (amount > 0)
// printstats("Sent", amount);
return amount;
}
/*
* Receive a file.
*/
int tftp_recvfile(int f, union sock_addr *peeraddr,
int fd, const char *name, const char *mode)
{
struct tftphdr *ap;
struct tftphdr *dp;
int n;
volatile u_short block;
volatile int size, firsttrip;
volatile unsigned long amount;
union sock_addr from;
socklen_t fromlen;
FILE *file;
volatile int convert; /* true if converting crlf -> lf */
u_short dp_opcode, dp_block;
startclock();
dp = w_init();
ap = (struct tftphdr *)ackbuf;
convert = !strcmp(mode, "netascii");
file = fdopen(fd, convert ? "wt" : "wb");
block = 1;
firsttrip = 1;
amount = 0;
bsd_signal(SIGALRM, timer);
do {
if (firsttrip) {
size = makerequest(RRQ, name, ap, mode);
firsttrip = 0;
} else {
ap->th_opcode = htons((u_short) ACK);
ap->th_block = htons((u_short) block);
size = 4;
block++;
}
timeout = 0;
(void)sigsetjmp(timeoutbuf, 1);
send_ack:
if (trace)
tpacket("sent", ap, size);
if (sendto(f, ackbuf, size, 0, &(peeraddr->sa),
SOCKLEN(peeraddr)) != size) {
alarm(0);
perror("tftp: sendto");
goto abort;
}
write_behind(file, convert);
for (;;) {
alarm(rexmtval);
do {
fromlen = sizeof(from);
n = recvfrom(f, dp, PKTSIZE, 0,
&from.sa, &fromlen);
} while (n <= 0);
alarm(0);
if (n < 0) {
perror("tftp: recvfrom");
goto abort;
}
sa_set_port(peeraddr, SOCKPORT(&from)); /* added */
if (trace)
tpacket("received", dp, n);
/* should verify client address */
dp_opcode = ntohs((u_short) dp->th_opcode);
dp_block = ntohs((u_short) dp->th_block);
if (dp_opcode == ERROR) {
printf("Error code %d: %s\n", dp_block, dp->th_msg);
goto abort;
}
if (dp_opcode == DATA) {
int j;
if (dp_block == block) {
break; /* have next packet */
}
/* On an error, try to synchronize
* both sides.
*/
j = synchnet(f);
if (j && trace) {
printf("discarded %d packets\n", j);
}
if (dp_block == (block - 1)) {
goto send_ack; /* resend ack */
}
}
}
/* size = write(fd, dp->th_data, n - 4); */
size = writeit(file, &dp, n - 4, convert);
if (size < 0) {
nak(f, peeraddr, errno + 100, NULL);
break;
}
amount += size;
} while (size == SEGSIZE);
abort: /* ok to ack, since user */
ap->th_opcode = htons((u_short) ACK); /* has seen err msg */
ap->th_block = htons((u_short) block);
(void)sendto(f, ackbuf, 4, 0, (struct sockaddr *)peeraddr,
SOCKLEN(peeraddr));
write_behind(file, convert); /* flush last buffer */
fclose(file);
stopclock();
//if (amount > 0)
// printstats("Received", amount);
return amount;
}
/*
* Send the requested file.
*/
void
sendfile(int fd, char *name, char *mode)
{
register struct tftphdr *ap; /* data and ack packets */
struct tftphdr *dp;
volatile int block = 0, size = 0;
int n;
volatile unsigned long amount = 0;
struct sockaddr_in from;
socklen_t fromlen;
volatile int convert; /* true if doing nl->crlf conversion */
FILE *file;
startclock(); /* start stat's clock */
dp = r_init(); /* reset fillbuf/read-ahead code */
ap = (struct tftphdr *)ackbuf;
file = fdopen(fd, "r");
convert = !strcmp(mode, "netascii");
signal(SIGALRM, timer);
do {
if (block == 0)
size = makerequest(WRQ, name, dp, mode) - 4;
else {
/* size = read(fd, dp->th_data, SEGSIZE); */
size = readit(file, &dp, convert);
if (size < 0) {
nak(errno + 100);
break;
}
dp->th_opcode = htons((u_short)DATA);
dp->th_block = htons((u_short)block);
}
timeout = 0;
(void) sigsetjmp(timeoutbuf, 1);
send_data:
if (trace)
tpacket("sent", dp, size + 4);
n = sendto(f, dp, size + 4, 0,
(struct sockaddr *)&s_inn, sizeof(s_inn));
if (n != size + 4) {
perror("tftp: sendto");
goto abort;
}
read_ahead(file, convert);
for ( ; ; ) {
alarm(rexmtval);
do {
fromlen = sizeof (from);
n = recvfrom(f, ackbuf, sizeof (ackbuf), 0,
(struct sockaddr *)&from, &fromlen);
} while (n <= 0);
alarm(0);
if (n < 0) {
perror("tftp: recvfrom");
goto abort;
}
s_inn.sin_port = from.sin_port; /* added */
if (trace)
tpacket("received", ap, n);
/* should verify packet came from server */
ap->th_opcode = ntohs(ap->th_opcode);
ap->th_block = ntohs(ap->th_block);
if (ap->th_opcode == ERROR) {
printf("Error code %d: %s\n", ap->th_code,
ap->th_msg);
goto abort;
}
if (ap->th_opcode == ACK) {
volatile int j = 0;
if (ap->th_block == block) {
break;
}
/* On an error, try to synchronize
* both sides.
*/
j = synchnet(f);
if (j && trace) {
printf("discarded %d packets\n",
j);
}
if (ap->th_block == (block-1)) {
goto send_data;
}
}
}
if (block > 0)
amount += size;
block++;
} while (size == SEGSIZE || block == 1);
abort:
fclose(file);
stopclock();
if (amount > 0)
printstats("Sent", amount);
}
