void
process_udp_request(int ksoc, struct packet *pkt)
{
char *packet = pkt->data;
unsigned char version, auth_msg_type;
version = *packet++;
if (version != KRB_PROT_VERSION) {
err_packet(ksoc, pkt, KERB_ERR_PKT_VER,
"packet version number unknown");
return;
}
auth_msg_type = *packet++;
pkt->byteOrder = auth_msg_type & 1;
pkt->rest = packet;
switch (auth_msg_type & ~1) {
case AUTH_MSG_KDC_REQUEST:
process_udp_auth(ksoc, pkt);
break;
case AUTH_MSG_APPL_REQUEST:
process_udp_appl(ksoc, pkt);
break;
default:
printf("unknown msg type 0x%x\n", auth_msg_type);
err_packet(ksoc, pkt, KERB_ERR_BAD_MSG_TYPE,
"message type not supported");
return;
}
return;
}
int
process_udp_appl(int ksoc, struct packet *pkt)
{
char *packet = pkt->rest;
afs_int32 kvno;
char realm[MAXKTCREALMLEN];
char ticket[MAXKTCTICKETLEN];
char auth[3 * MAXKTCNAMELEN + 4 + 5];
int slen;
int ticketLen, authLen;
afs_int32 code;
if (krb_udp_debug) {
printf("Processing APPL Request\n");
}
kvno = *packet++;
getstr(realm);
ticketLen = *(unsigned char *)packet++;
authLen = *(unsigned char *)packet++;
if (ticketLen > sizeof(ticket)) {
err_packet(ksoc, pkt, KERB_ERR_TEXT_LENGTH, "ticket too long");
return -1;
}
memcpy(ticket, packet, ticketLen);
packet += ticketLen;
if (authLen > sizeof(auth)) {
err_packet(ksoc, pkt, KERB_ERR_TEXT_LENGTH, "authenticator too long");
return -1;
}
memcpy(auth, packet, authLen);
pkt->rest = packet + authLen;
code =
UDP_GetTicket(ksoc, pkt, kvno, realm, ticket, ticketLen, auth,
authLen);
if (code) {
if (code == KANOENT)
code = KERB_ERR_PRINCIPAL_UNKNOWN;
err_packet(ksoc, pkt, code, (char *)afs_error_message(code));
return -1;
}
return 0;
}
int
process_udp_auth(int ksoc, struct packet *pkt)
{
char *packet = pkt->rest;
char name[MAXKTCNAMELEN];
char inst[MAXKTCNAMELEN];
char realm[MAXKTCREALMLEN];
char sname[MAXKTCNAMELEN];
char sinst[MAXKTCNAMELEN];
int slen;
Date now = time(0);
Date startTime, endTime;
unsigned char lifetime;
afs_int32 code;
pkt->name = packet;
getstr(name);
pkt->inst = packet;
getstr(inst);
pkt->realm = packet;
getstr(realm);
if (krb_udp_debug) {
printf("Processing KDC Request from '%s'.'%s'@'%s'\n", name, inst,
realm);
}
if ((strlen(realm) > 0) && (strcmp(realm, lrealm) != 0)) {
err_packet(ksoc, pkt, KERB_ERR_NONNULL_REALM,
"null realm name not allowed");
return -1;
}
memcpy(&startTime, packet, sizeof(startTime));
packet += sizeof(startTime);
startTime = ktohl(pkt->byteOrder, startTime);
pkt->time = startTime;
lifetime = *packet++;
endTime = life_to_time(startTime, lifetime);
code = tkt_CheckTimes(startTime, endTime, now);
if (code < 0) {
err_packet(ksoc, pkt, KERB_ERR_BAD_LIFETIME,
"requested ticket lifetime invalid");
return -1;
}
getstr(sname);
getstr(sinst);
if ((packet - pkt->data) != pkt->len) {
err_packet(ksoc, pkt, KERB_ERR_PKT_LENGTH,
"packet length inconsistent");
return -1;
}
pkt->rest = packet;
code =
UDP_Authenticate(ksoc, &pkt->from, name, inst, startTime, endTime,
sname, sinst);
if (code) {
if (code == KANOENT) {
code = KERB_ERR_PRINCIPAL_UNKNOWN;
err_packet(ksoc, pkt, code, (char *)afs_error_message(code));
} else if (code == KAPWEXPIRED) {
code = KERB_ERR_NAME_EXP;
err_packet(ksoc, pkt, code, "password has expired");
} else
err_packet(ksoc, pkt, code, (char *)afs_error_message(code));
}
return 0;
}
/*
*This function is called when the client would like to upload a file to the server.
*/
void
tsend (char *pFilename, struct sockaddr_in server, char *pMode, int sock)
{
int len, server_len, opcode, ssize = 0, n, i, j, bcount = 0, tid;
unsigned short int count = 0, rcount = 0, acked = 0;
unsigned char filebuf[MAXDATASIZE + 1];
unsigned char packetbuf[MAXACKFREQ][MAXDATASIZE + 12],
recvbuf[MAXDATASIZE + 12];
char filename[128], mode[12], *bufindex; //fullpath[196],
struct sockaddr_in ack;
FILE *fp; /* pointer to the file we will be sending */
strcpy (filename, pFilename); //copy the pointer to the filename into a real array
strcpy (mode, pMode); //same as above
if (debug)
printf ("Client: branched to file send function\n");
/*At this point I have to wait to recieve an ACK from the server before I start sending the file*/
/*open the file to read */
fp = fopen (filename, "r");
if (fp == NULL)
{ //if the pointer is null then the file can't be opened - Bad perms OR no such file
if (debug)
printf ("Client: sending bad file: file not found (%s)\n", filename);
return;
}
else
{
if (debug)
printf ("Client: Sending file... (source: %s)\n", filename);
}
//get ACK for WRQ
/* The following 'for' loop is used to recieve/timeout ACKs */
for (j = 0; j < RETRIES - 2; j++)
{
server_len = sizeof (ack);
errno = EAGAIN;
n = -1;
for (i = 0; errno == EAGAIN && i <= TIMEOUT && n < 0; i++)
{
n = recvfrom (sock, recvbuf, sizeof (recvbuf), MSG_DONTWAIT,
(struct sockaddr *) &ack, (socklen_t *) & server_len);
usleep (1000);
}
/* if(debug)
ip_port (ack); print the vlaue recived from the server */
tid = ntohs (ack.sin_port); //get the tid of the server.
server.sin_port = htons (tid); //set the tid for rest of the transfer
if (n < 0 && errno != EAGAIN)
{
if (debug)
printf
("Client: could not receive from the server (errno: %d n: %d)\n",
errno, n);
//resend packet
}
else if (n < 0 && errno == EAGAIN)
{
if (debug)
printf ("Client: Timeout waiting for ack (errno: %d n: %d)\n",
errno, n);
//resend packet
}
else
{ /*changed client to server here */
if (server.sin_addr.s_addr != ack.sin_addr.s_addr) /* checks to ensure send to ip is same from ACK IP */
{
if (debug)
printf
("Client: Error recieving ACK (ACK from invalid address)\n");
j--; /* in this case someone else connected to our port. Ignore this fact and retry getting the ack */
continue;
}
if (tid != ntohs (server.sin_port)) /* checks to ensure get from the correct TID */
{
if (debug)
printf
("Client: Error recieving file (data from invalid tid)\n");
len = err_packet (5, err_msg[5], buf);
if (sendto (sock, buf, len, 0, (struct sockaddr *) &server, sizeof (server)) != len) /* send the data packet */
{
printf
("Client: Mismatch in number of sent bytes while trying to send mode error packet\n");
}
/* if (debug)
ip_port(server); */
j--;
continue; /* we aren't going to let another connection spoil our first connection */
}
/* this formatting code is just like the code in the main function */
bufindex = (char *) recvbuf; //start our pointer going
if (bufindex++[0] != 0x00)
printf ("Client: bad first nullbyte!\n");
opcode = *bufindex++;
rcount = *bufindex++ << 8;
rcount &= 0xff00;
rcount += (*bufindex++ & 0x00ff);
if (opcode != 4 || rcount != count) /* ack packet should have code 4 (ack) and should be acking the packet we just sent */
{
if (debug)
printf
("Client: Remote host failed to ACK proper data packet # %d (got OP: %d Block: %d)\n",
count, opcode, rcount);
/* sending error message */
if (opcode > 5)
{
len = err_packet (4, err_msg[4], buf);
if (sendto (sock, buf, len, 0, (struct sockaddr *) &server, sizeof (server)) != len) /* send the data packet */
{
printf
("Client: Mismatch in number of sent bytes while trying to send mode error packet\n");
}
}
/* from here we will loop back and resend */
/* if (debug)
ip_port(server); */
}
else
{
if (debug)
printf ("Client: Remote host successfully ACK'd (#%d)\n",
rcount);
break;
}
} //end of else
if (debug)
printf ("Client: Ack(s) lost. Resending complete.\n");
}
/* The ack sending 'for' loop ends here */
memset (filebuf, 0, sizeof (filebuf)); //clear the filebuf
while (1) /* our break statement will escape us when we are done */
{
acked = 0;
ssize = fread (filebuf, 1, datasize, fp);
if (debug)
{
printf
("The first data block has been read from the file and will be sent to the server\n");
printf ("The size read from the file is: %d\n", ssize);
}
count++; /* count number of datasize byte portions we read from the file */
if (count == 1) /* we always look for an ack on the FIRST packet */
bcount = 0;
else if (count == 2) /* The second packet will always start our counter at zreo. This special case needs to exist to avoid a DBZ when count = 2 - 2 = 0 */
bcount = 0;
else
bcount = (count - 2) % ackfreq;
sprintf ((char *) packetbuf[bcount], "%c%c%c%c", 0x00, 0x03, 0x00, 0x00); /* build data packet but write out the count as zero */
memcpy ((char *) packetbuf[bcount] + 4, filebuf, ssize);
len = 4 + ssize;
packetbuf[bcount][2] = (count & 0xFF00) >> 8; //fill in the count (top number first)
packetbuf[bcount][3] = (count & 0x00FF); //fill in the lower part of the count
if (debug)
printf ("Client: Sending packet # %04d (length: %d file chunk: %d)\n",
count, len, ssize);
/* send the data packet */
if (sendto
(sock, packetbuf[bcount], len, 0, (struct sockaddr *) &server,
sizeof (server)) != len)
{
if (debug)
printf ("Client: Mismatch in number of sent bytes\n");
return;
}
if (debug)
{
ip_port (server);
printf ("==count: %d bcount: %d ssize: %d datasize: %d\n", count,
bcount, ssize, datasize);
}
//if ((count - 1) == 0 || ((count - 1) % ackfreq) == 0 || ssize != datasize)
if (((count) % ackfreq) == 0 || ssize != datasize)
{
if (debug)
printf ("-- I will get an ACK\n");
/* The following 'for' loop is used to recieve/timeout ACKs */
for (j = 0; j < RETRIES; j++)
{
server_len = sizeof (ack);
errno = EAGAIN;
n = -1;
for (i = 0; errno == EAGAIN && i <= TIMEOUT && n < 0; i++)
{
n =
recvfrom (sock, recvbuf, sizeof (recvbuf), MSG_DONTWAIT,
(struct sockaddr *) &ack,
(socklen_t *) & server_len);
/* if (debug)
ip_port(ack); */
usleep (1000);
}
if (n < 0 && errno != EAGAIN)
{
if (debug)
printf
("Client: could not receive from the server (errno: %d n: %d)\n",
errno, n);
//resend packet
}
else if (n < 0 && errno == EAGAIN)
{
if (debug)
printf
("Client: Timeout waiting for ack (errno: %d n: %d)\n",
errno, n);
//resend packet
}
else
{ /* checks to ensure send to ip is same from ACK IP */
if (server.sin_addr.s_addr != ack.sin_addr.s_addr)
{
if (debug)
printf
("Client: Error recieving ACK (ACK from invalid address)\n");
/* in this case someone else connected to our port. Ignore this fact and retry getting the ack */
j--;
continue;
}
if (tid != ntohs (server.sin_port)) /* checks to ensure get from the correct TID */
{
if (debug)
printf
("Client: Error recieving file (data from invalid tid)\n");
len = err_packet (5, err_msg[5], buf);
/* send the data packet */
if (sendto
(sock, buf, len, 0, (struct sockaddr *) &server,
sizeof (server)) != len)
{
printf
("Client: Mismatch in number of sent bytes while trying to send mode error packet\n");
}
/*if (debug)
ip_port(server); */
j--;
continue; /* we aren't going to let another connection spoil our first connection */
}
/* this formatting code is just like the code in the main function */
bufindex = (char *) recvbuf; //start our pointer going
if (bufindex++[0] != 0x00)
printf ("Client: bad first nullbyte!\n");
opcode = *bufindex++;
rcount = *bufindex++ << 8;
rcount &= 0xff00;
rcount += (*bufindex++ & 0x00ff);
if (opcode != 4 || rcount != count) /* ack packet should have code 4 (ack) and should be acking the packet we just sent */
{
if (debug)
printf
("Client: Remote host failed to ACK proper data packet # %d (got OP: %d Block: %d)\n",
count, opcode, rcount);
/* sending error message */
if (opcode > 5)
{
len = err_packet (4, err_msg[4], buf);
if (sendto (sock, buf, len, 0, (struct sockaddr *) &server, sizeof (server)) != len) /* send the data packet */
{
printf
("Client: Mismatch in number of sent bytes while trying to send mode error packet\n");
}
/*if (debug)
ip_port(server); */
}
/* from here we will loop back and resend */
}
else
{
if (debug)
printf
("Client: Remote host successfully ACK'd (#%d)\n",
rcount);
break;
}
}
for (i = 0; i <= bcount; i++)
{
if (sendto (sock, packetbuf[i], len, 0, (struct sockaddr *) &server, sizeof (server)) != len) /* resend the data packet */
{
if (debug)
printf ("Client: Mismatch in number of sent bytes\n");
return;
}
if (debug)
{
printf ("Client: Ack(s) lost. Resending: %d\n",
count - bcount + i);
ip_port (server);
}
}
if (debug)
printf ("Client: Ack(s) lost. Resending complete.\n");
}
/* The ack sending 'for' loop ends here */
}
else if (debug)
{
printf
("Client: Not attempting to recieve ack. Not required. count: %d\n",
count);
n = recvfrom (sock, recvbuf, sizeof (recvbuf), MSG_DONTWAIT, (struct sockaddr *) &ack, (socklen_t *) & server_len); /* just do a quick check incase the remote host is trying with ackfreq = 1 */
/*if (debug)
ip_port(ack); */
}
if (j == RETRIES)
{
if (debug)
printf ("Client: Ack Timeout. Aborting transfer\n");
fclose (fp);
return;
}
if (ssize != datasize)
break;
memset (filebuf, 0, sizeof (filebuf)); /* fill the filebuf with zeros so that when the fread fills it, it is a null terminated string */
}
fclose (fp);
if (debug)
printf ("Client: File sent successfully\n");
return;
} //end of tsend function
