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Now have enough functions to implement a standard TFTP client in around 50 

lines of code.
This commit is contained in:
Michael Brown 2005-06-01 11:01:59 +00:00
parent 7d63b39e3d
commit 0b048e9cfb
2 changed files with 132 additions and 11 deletions
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25
src/include/tftpcore.h Normal file
View File

@ -0,0 +1,25 @@
#ifndef TFTPCORE_H
#define TFTPCORE_H
#include "tftp.h"
extern int await_tftp ( int ival, void *ptr, unsigned short ptype,
struct iphdr *ip, struct udphdr *udp,
struct tcphdr *tcp );
extern int tftp_open ( struct tftp_state *state, const char *filename,
union tftp_any **reply );
extern int tftp_process_opts ( struct tftp_state *state,
struct tftp_oack *oack );
extern int tftp_ack_nowait ( struct tftp_state *state );
extern int tftp_ack ( struct tftp_state *state, union tftp_any **reply );
extern int tftp_error ( struct tftp_state *state, int errcode,
const char *errmsg );
extern void tftp_set_errno ( struct tftp_error *error );
#endif /* TFTPCORE_H */

118
src/proto/tftpcore.c
View File

@ -2,6 +2,7 @@
#include "tcp.h" /* for struct tcphdr */
#include "errno.h"
#include "etherboot.h"
#include "tftpcore.h"
/** @file
*
@ -16,6 +17,9 @@
* Wait for a TFTP packet
*
* @v ptr Pointer to a struct tftp_state
* @v tftp_state::server::sin_addr TFTP server IP address
* @v tftp_state::client::sin_addr Client multicast IP address, or 0.0.0.0
* @v tftp_state::client::sin_port Client UDP port
* @v ip IP header
* @v udp UDP header
* @ret True This is our TFTP packet
@ -74,16 +78,20 @@ int await_tftp ( int ival __unused, void *ptr, unsigned short ptype __unused,
* @v filename File name
* @ret True Received a non-error response
* @ret False Received error response / no response
* @ret tftp_state::server::sin_port TFTP server UDP port
* @ret tftp_state::client::sin_port Client UDP port
* @ret tftp_state::client::blksize Always #TFTP_DEFAULT_BLKSIZE
* @ret *tftp The server's response, if any
* @ret tftp_state::blksize Always #TFTP_DEFAULT_BLKSIZE
* @ret *reply The server's response, if any
* @err #PXENV_STATUS_TFTP_OPEN_TIMEOUT TFTP open timed out
* @err other As returned by udp_transmit()
* @err other As set by tftp_set_errno()
*
* Send a TFTP/TFTM/MTFTP RRQ (read request) to a TFTP server, and
* return the server's reply (which may be an OACK, DATA or ERROR
* packet). The server's reply will not be acknowledged, or processed
* in any way.
*
* If tftp_state::server::sin_port is 0, the standard tftp server port
* If tftp_state::server::sin_port is 0, the standard TFTP server port
* (#TFTP_PORT) will be used.
*
* If tftp_state::client::sin_addr is not 0.0.0.0, it will be used as
@ -121,6 +129,10 @@ int await_tftp ( int ival __unused, void *ptr, unsigned short ptype __unused,
* be assumed until the OACK packet is processed (by a subsequent call
* to tftp_process_opts()).
*
* tftp_state::server::sin_port will be set to the UDP port from which
* the server's response originated. This may or may not be the port
* to which the open request was sent.
*
* The options "blksize", "tsize" and "multicast" will always be
* appended to a TFTP open request. Servers that do not understand
* any of these options should simply ignore them.
@ -129,9 +141,11 @@ int await_tftp ( int ival __unused, void *ptr, unsigned short ptype __unused,
* the caller is responsible for calling join_group() and
* leave_group() at appropriate times.
*
* If the response from the server is a TFTP ERROR packet, tftp_open()
* will return False and #errno will be set accordingly.
*/
int tftp_open ( struct tftp_state *state, const char *filename,
union tftp_any **tftp ) {
union tftp_any **reply ) {
static unsigned short lport = 2000; /* local port */
int fixed_lport;
struct tftp_rrq rrq;
@ -164,7 +178,7 @@ int tftp_open ( struct tftp_state *state, const char *filename,
state->blksize = TFTP_DEFAULT_BLKSIZE;
/* Nullify received packet pointer */
*tftp = NULL;
*reply = NULL;
/* Transmit RRQ until we get a response */
for ( retry = 0 ; retry < MAX_TFTP_RETRIES ; retry++ ) {
@ -186,7 +200,13 @@ int tftp_open ( struct tftp_state *state, const char *filename,
/* Wait for response */
if ( await_reply ( await_tftp, 0, state, timeout ) ) {
*tftp = ( union tftp_any * ) &nic.packet[ETH_HLEN];
*reply = ( union tftp_any * ) &nic.packet[ETH_HLEN];
state->server.sin_port =
ntohs ( (*reply)->common.udp.dest );
if ( ntohs ( (*reply)->common.opcode ) == TFTP_ERROR ){
tftp_set_errno ( &(*reply)->error );
return 0;
}
return 1;
}
}
@ -321,13 +341,14 @@ int tftp_process_opts ( struct tftp_state *state, struct tftp_oack *oack ) {
* @v tftp_state::block Most recently received block number
* @ret True Acknowledgement packet was sent
* @ret False Acknowledgement packet was not sent
* @err other As returned by udp_transmit()
*
* Send a TFTP ACK packet for the most recently received block.
*
* This sends only a single ACK packet; it does not wait for the
* server's response.
*/
int tftp_ack ( struct tftp_state *state ) {
int tftp_ack_nowait ( struct tftp_state *state ) {
struct tftp_ack ack;
ack.opcode = htons ( TFTP_ACK );
@ -337,6 +358,59 @@ int tftp_ack ( struct tftp_state *state ) {
sizeof ( ack ), &ack );
}
/**
* Acknowledge a TFTP packet and wait for a response
*
* @v state TFTP transfer state
* @v tftp_state::server::sin_addr TFTP server IP address
* @v tftp_state::server::sin_port TFTP server UDP port
* @v tftp_state::client::sin_port Client UDP port
* @v tftp_state::block Most recently received block number
* @ret True Received a non-error response
* @ret False Received error response / no response
* @ret *reply The server's response, if any
* @err #PXENV_STATUS_TFTP_READ_TIMEOUT Timed out waiting for a response
* @err other As returned by tftp_ack_nowait()
* @err other As set by tftp_set_errno()
*
* Send a TFTP ACK packet for the most recently received data block,
* and keep transmitting this ACK until we get a response from the
* server (e.g. a new data block).
*
* If the response is a TFTP DATA packet, no processing is done.
* Specifically, the block number is not checked to ensure that this
* is indeed the next data block in the sequence, nor is
* tftp_state::block updated with the new block number.
*
* If the response from the server is a TFTP ERROR packet, tftp_open()
* will return False and #errno will be set accordingly.
*/
int tftp_ack ( struct tftp_state *state, union tftp_any **reply ) {
int retry;
*reply = NULL;
for ( retry = 0 ; retry < MAX_TFTP_RETRIES ; retry++ ) {
long timeout = rfc2131_sleep_interval ( TFTP_REXMT, retry );
/* ACK the last data block */
if ( ! tftp_ack_nowait ( state ) ) {
DBG ( "TFTP: could not send ACK: %m\n" );
return 0;
}
if ( await_reply ( await_tftp, 0, &state, timeout ) ) {
/* We received a reply */
*reply = ( union tftp_any * ) &nic.packet[ETH_HLEN];
if ( ntohs ( (*reply)->common.opcode ) == TFTP_ERROR ){
tftp_set_errno ( &(*reply)->error );
return 0;
}
return 1;
}
}
DBG ( "TFTP: ACK retries exceeded\n" );
errno = PXENV_STATUS_TFTP_READ_TIMEOUT;
return 0;
}
/**
* Send a TFTP error
*
@ -344,7 +418,7 @@ int tftp_ack ( struct tftp_state *state ) {
* @v tftp_state::server::sin_addr TFTP server IP address
* @v tftp_state::server::sin_port TFTP server UDP port
* @v tftp_state::client::sin_port Client UDP port
* @v err TFTP error code
* @v errcode TFTP error code
* @v errmsg Descriptive error string
* @ret True Error packet was sent
* @ret False Error packet was not sent
@ -352,14 +426,36 @@ int tftp_ack ( struct tftp_state *state ) {
* Send a TFTP ERROR packet back to the server to terminate the
* transfer.
*/
int tftp_error ( struct tftp_state *state, int err, const char *errmsg ) {
int tftp_error ( struct tftp_state *state, int errcode, const char *errmsg ) {
struct tftp_error error;
DBG ( "TFTPCORE: aborting with error %d (%s)\n", err, errmsg );
DBG ( "TFTPCORE: aborting with error %d (%s)\n", errcode, errmsg );
error.opcode = htons ( TFTP_ERROR );
error.errcode = htons ( err );
error.errcode = htons ( errcode );
strncpy ( error.errmsg, errmsg, sizeof ( error.errmsg ) );
return udp_transmit ( state->server.sin_addr.s_addr,
state->client.sin_port, state->server.sin_port,
sizeof ( error ), &error );
}
/**
* Interpret a TFTP error
*
* @v error Pointer to a struct tftp_error
*
* Sets #errno based on the error code in a TFTP ERROR packet.
*/
void tftp_set_errno ( struct tftp_error *error ) {
static int errmap[] = {
[TFTP_ERR_FILE_NOT_FOUND] = PXENV_STATUS_TFTP_FILE_NOT_FOUND,
[TFTP_ERR_ACCESS_DENIED] = PXENV_STATUS_TFTP_ACCESS_VIOLATION,
[TFTP_ERR_ILLEGAL_OP] = PXENV_STATUS_TFTP_UNKNOWN_OPCODE,
};
unsigned int errcode = ntohs ( error->errcode );
errno = 0;
if ( errcode < ( sizeof(errmap) / sizeof(errmap[0]) ) )
errno = errmap[errcode];
if ( ! errno )
errno = PXENV_STATUS_TFTP_ERROR_OPCODE;
}