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curl/lib/tftp.c
Stefan Eissing d7b6ce64ce
lib: replace readwrite with write_resp 
This clarifies the handling of server responses by folding the code for
the complicated protocols into their protocol handlers. This concerns
mainly HTTP and its bastard sibling RTSP.

The terms "read" and "write" are often used without clear context if
they refer to the connect or the client/application side of a
transfer. This PR uses "read/write" for operations on the client side
and "send/receive" for the connection, e.g. server side. If this is
considered useful, we can revisit renaming of further methods in another
PR.

Curl's protocol handler `readwrite()` method been changed:

```diff
-  CURLcode (*readwrite)(struct Curl_easy *data, struct connectdata *conn,
-                        const char *buf, size_t blen,
-                        size_t *pconsumed, bool *readmore);
+  CURLcode (*write_resp)(struct Curl_easy *data, const char *buf, size_t blen,
+                         bool is_eos, bool *done);
```

The name was changed to clarify that this writes reponse data to the
client side. The parameter changes are:

* `conn` removed as it always operates on `data->conn`
* `pconsumed` removed as the method needs to handle all data on success
* `readmore` removed as no longer necessary
* `is_eos` as indicator that this is the last call for the transfer
  response (end-of-stream).
* `done` TRUE on return iff the transfer response is to be treated as
  finished

This change affects many files only because of updated comments in
handlers that provide no implementation. The real change is that the
HTTP protocol handlers now provide an implementation.

The HTTP protocol handlers `write_resp()` implementation will get passed
**all** raw data of a server response for the transfer. The HTTP/1.x
formatted status and headers, as well as the undecoded response
body. `Curl_http_write_resp_hds()` is used internally to parse the
response headers and pass them on. This method is public as the RTSP
protocol handler also uses it.

HTTP/1.1 "chunked" transport encoding is now part of the general
*content encoding* writer stack, just like other encodings. A new flag
`CLIENTWRITE_EOS` was added for the last client write. This allows
writers to verify that they are in a valid end state. The chunked
decoder will check if it indeed has seen the last chunk.

The general response handling in `transfer.c:466` happens in function
`readwrite_data()`. This mainly operates now like:

```
static CURLcode readwrite_data(data, ...)
{
  do {
    Curl_xfer_recv_resp(data, buf)
    ...
    Curl_xfer_write_resp(data, buf)
    ...
  } while(interested);
  ...
}
```

All the response data handling is implemented in
`Curl_xfer_write_resp()`. It calls the protocol handler's `write_resp()`
implementation if available, or does the default behaviour.

All raw response data needs to pass through this function. Which also
means that anyone in possession of such data may call
`Curl_xfer_write_resp()`.

Closes #12480
2024-01-13 17:23:42 +01:00

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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#ifndef CURL_DISABLE_TFTP
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#include "urldata.h"
#include <curl/curl.h>
#include "cf-socket.h"
#include "transfer.h"
#include "sendf.h"
#include "tftp.h"
#include "progress.h"
#include "connect.h"
#include "strerror.h"
#include "sockaddr.h" /* required for Curl_sockaddr_storage */
#include "multiif.h"
#include "url.h"
#include "strcase.h"
#include "speedcheck.h"
#include "select.h"
#include "escape.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
/* RFC2348 allows the block size to be negotiated */
#define TFTP_BLKSIZE_DEFAULT 512
#define TFTP_OPTION_BLKSIZE "blksize"
/* from RFC2349: */
#define TFTP_OPTION_TSIZE "tsize"
#define TFTP_OPTION_INTERVAL "timeout"
typedef enum {
TFTP_MODE_NETASCII = 0,
TFTP_MODE_OCTET
} tftp_mode_t;
typedef enum {
TFTP_STATE_START = 0,
TFTP_STATE_RX,
TFTP_STATE_TX,
TFTP_STATE_FIN
} tftp_state_t;
typedef enum {
TFTP_EVENT_NONE = -1,
TFTP_EVENT_INIT = 0,
TFTP_EVENT_RRQ = 1,
TFTP_EVENT_WRQ = 2,
TFTP_EVENT_DATA = 3,
TFTP_EVENT_ACK = 4,
TFTP_EVENT_ERROR = 5,
TFTP_EVENT_OACK = 6,
TFTP_EVENT_TIMEOUT
} tftp_event_t;
typedef enum {
TFTP_ERR_UNDEF = 0,
TFTP_ERR_NOTFOUND,
TFTP_ERR_PERM,
TFTP_ERR_DISKFULL,
TFTP_ERR_ILLEGAL,
TFTP_ERR_UNKNOWNID,
TFTP_ERR_EXISTS,
TFTP_ERR_NOSUCHUSER, /* This will never be triggered by this code */
/* The remaining error codes are internal to curl */
TFTP_ERR_NONE = -100,
TFTP_ERR_TIMEOUT,
TFTP_ERR_NORESPONSE
} tftp_error_t;
struct tftp_packet {
unsigned char *data;
};
struct tftp_state_data {
tftp_state_t state;
tftp_mode_t mode;
tftp_error_t error;
tftp_event_t event;
struct Curl_easy *data;
curl_socket_t sockfd;
int retries;
int retry_time;
int retry_max;
time_t rx_time;
struct Curl_sockaddr_storage local_addr;
struct Curl_sockaddr_storage remote_addr;
curl_socklen_t remote_addrlen;
int rbytes;
int sbytes;
int blksize;
int requested_blksize;
unsigned short block;
struct tftp_packet rpacket;
struct tftp_packet spacket;
};
/* Forward declarations */
static CURLcode tftp_rx(struct tftp_state_data *state, tftp_event_t event);
static CURLcode tftp_tx(struct tftp_state_data *state, tftp_event_t event);
static CURLcode tftp_connect(struct Curl_easy *data, bool *done);
static CURLcode tftp_disconnect(struct Curl_easy *data,
struct connectdata *conn,
bool dead_connection);
static CURLcode tftp_do(struct Curl_easy *data, bool *done);
static CURLcode tftp_done(struct Curl_easy *data,
CURLcode, bool premature);
static CURLcode tftp_setup_connection(struct Curl_easy *data,
struct connectdata *conn);
static CURLcode tftp_multi_statemach(struct Curl_easy *data, bool *done);
static CURLcode tftp_doing(struct Curl_easy *data, bool *dophase_done);
static int tftp_getsock(struct Curl_easy *data, struct connectdata *conn,
curl_socket_t *socks);
static CURLcode tftp_translate_code(tftp_error_t error);
/*
* TFTP protocol handler.
*/
const struct Curl_handler Curl_handler_tftp = {
"TFTP", /* scheme */
tftp_setup_connection, /* setup_connection */
tftp_do, /* do_it */
tftp_done, /* done */
ZERO_NULL, /* do_more */
tftp_connect, /* connect_it */
tftp_multi_statemach, /* connecting */
tftp_doing, /* doing */
tftp_getsock, /* proto_getsock */
tftp_getsock, /* doing_getsock */
ZERO_NULL, /* domore_getsock */
ZERO_NULL, /* perform_getsock */
tftp_disconnect, /* disconnect */
ZERO_NULL, /* write_resp */
ZERO_NULL, /* connection_check */
ZERO_NULL, /* attach connection */
PORT_TFTP, /* defport */
CURLPROTO_TFTP, /* protocol */
CURLPROTO_TFTP, /* family */
PROTOPT_NOTCPPROXY | PROTOPT_NOURLQUERY /* flags */
};
/**********************************************************
*
* tftp_set_timeouts -
*
* Set timeouts based on state machine state.
* Use user provided connect timeouts until DATA or ACK
* packet is received, then use user-provided transfer timeouts
*
*
**********************************************************/
static CURLcode tftp_set_timeouts(struct tftp_state_data *state)
{
time_t maxtime, timeout;
timediff_t timeout_ms;
bool start = (state->state == TFTP_STATE_START) ? TRUE : FALSE;
/* Compute drop-dead time */
timeout_ms = Curl_timeleft(state->data, NULL, start);
if(timeout_ms < 0) {
/* time-out, bail out, go home */
failf(state->data, "Connection time-out");
return CURLE_OPERATION_TIMEDOUT;
}
if(timeout_ms > 0)
maxtime = (time_t)(timeout_ms + 500) / 1000;
else
maxtime = 3600; /* use for calculating block timeouts */
/* Set per-block timeout to total */
timeout = maxtime;
/* Average reposting an ACK after 5 seconds */
state->retry_max = (int)timeout/5;
/* But bound the total number */
if(state->retry_max<3)
state->retry_max = 3;
if(state->retry_max>50)
state->retry_max = 50;
/* Compute the re-ACK interval to suit the timeout */
state->retry_time = (int)(timeout/state->retry_max);
if(state->retry_time<1)
state->retry_time = 1;
infof(state->data,
"set timeouts for state %d; Total % " CURL_FORMAT_CURL_OFF_T
", retry %d maxtry %d",
(int)state->state, timeout_ms, state->retry_time, state->retry_max);
/* init RX time */
time(&state->rx_time);
return CURLE_OK;
}
/**********************************************************
*
* tftp_set_send_first
*
* Event handler for the START state
*
**********************************************************/
static void setpacketevent(struct tftp_packet *packet, unsigned short num)
{
packet->data[0] = (unsigned char)(num >> 8);
packet->data[1] = (unsigned char)(num & 0xff);
}
static void setpacketblock(struct tftp_packet *packet, unsigned short num)
{
packet->data[2] = (unsigned char)(num >> 8);
packet->data[3] = (unsigned char)(num & 0xff);
}
static unsigned short getrpacketevent(const struct tftp_packet *packet)
{
return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
}
static unsigned short getrpacketblock(const struct tftp_packet *packet)
{
return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
}
static size_t tftp_strnlen(const char *string, size_t maxlen)
{
const char *end = memchr(string, '\0', maxlen);
return end ? (size_t) (end - string) : maxlen;
}
static const char *tftp_option_get(const char *buf, size_t len,
const char **option, const char **value)
{
size_t loc;
loc = tftp_strnlen(buf, len);
loc++; /* NULL term */
if(loc >= len)
return NULL;
*option = buf;
loc += tftp_strnlen(buf + loc, len-loc);
loc++; /* NULL term */
if(loc > len)
return NULL;
*value = &buf[strlen(*option) + 1];
return &buf[loc];
}
static CURLcode tftp_parse_option_ack(struct tftp_state_data *state,
const char *ptr, int len)
{
const char *tmp = ptr;
struct Curl_easy *data = state->data;
/* if OACK doesn't contain blksize option, the default (512) must be used */
state->blksize = TFTP_BLKSIZE_DEFAULT;
while(tmp < ptr + len) {
const char *option, *value;
tmp = tftp_option_get(tmp, ptr + len - tmp, &option, &value);
if(!tmp) {
failf(data, "Malformed ACK packet, rejecting");
return CURLE_TFTP_ILLEGAL;
}
infof(data, "got option=(%s) value=(%s)", option, value);
if(checkprefix(TFTP_OPTION_BLKSIZE, option)) {
long blksize;
blksize = strtol(value, NULL, 10);
if(!blksize) {
failf(data, "invalid blocksize value in OACK packet");
return CURLE_TFTP_ILLEGAL;
}
if(blksize > TFTP_BLKSIZE_MAX) {
failf(data, "%s (%d)", "blksize is larger than max supported",
TFTP_BLKSIZE_MAX);
return CURLE_TFTP_ILLEGAL;
}
else if(blksize < TFTP_BLKSIZE_MIN) {
failf(data, "%s (%d)", "blksize is smaller than min supported",
TFTP_BLKSIZE_MIN);
return CURLE_TFTP_ILLEGAL;
}
else if(blksize > state->requested_blksize) {
/* could realloc pkt buffers here, but the spec doesn't call out
* support for the server requesting a bigger blksize than the client
* requests */
failf(data, "%s (%ld)",
"server requested blksize larger than allocated", blksize);
return CURLE_TFTP_ILLEGAL;
}
state->blksize = (int)blksize;
infof(data, "%s (%d) %s (%d)", "blksize parsed from OACK",
state->blksize, "requested", state->requested_blksize);
}
else if(checkprefix(TFTP_OPTION_TSIZE, option)) {
long tsize = 0;
tsize = strtol(value, NULL, 10);
infof(data, "%s (%ld)", "tsize parsed from OACK", tsize);
/* tsize should be ignored on upload: Who cares about the size of the
remote file? */
if(!data->state.upload) {
if(!tsize) {
failf(data, "invalid tsize -:%s:- value in OACK packet", value);
return CURLE_TFTP_ILLEGAL;
}
Curl_pgrsSetDownloadSize(data, tsize);
}
}
}
return CURLE_OK;
}
static CURLcode tftp_option_add(struct tftp_state_data *state, size_t *csize,
char *buf, const char *option)
{
if(( strlen(option) + *csize + 1) > (size_t)state->blksize)
return CURLE_TFTP_ILLEGAL;
strcpy(buf, option);
*csize += strlen(option) + 1;
return CURLE_OK;
}
static CURLcode tftp_connect_for_tx(struct tftp_state_data *state,
tftp_event_t event)
{
CURLcode result;
#ifndef CURL_DISABLE_VERBOSE_STRINGS
struct Curl_easy *data = state->data;
infof(data, "%s", "Connected for transmit");
#endif
state->state = TFTP_STATE_TX;
result = tftp_set_timeouts(state);
if(result)
return result;
return tftp_tx(state, event);
}
static CURLcode tftp_connect_for_rx(struct tftp_state_data *state,
tftp_event_t event)
{
CURLcode result;
#ifndef CURL_DISABLE_VERBOSE_STRINGS
struct Curl_easy *data = state->data;
infof(data, "%s", "Connected for receive");
#endif
state->state = TFTP_STATE_RX;
result = tftp_set_timeouts(state);
if(result)
return result;
return tftp_rx(state, event);
}
static CURLcode tftp_send_first(struct tftp_state_data *state,
tftp_event_t event)
{
size_t sbytes;
ssize_t senddata;
const char *mode = "octet";
char *filename;
struct Curl_easy *data = state->data;
CURLcode result = CURLE_OK;
/* Set ascii mode if -B flag was used */
if(data->state.prefer_ascii)
mode = "netascii";
switch(event) {
case TFTP_EVENT_INIT: /* Send the first packet out */
case TFTP_EVENT_TIMEOUT: /* Resend the first packet out */
/* Increment the retry counter, quit if over the limit */
state->retries++;
if(state->retries>state->retry_max) {
state->error = TFTP_ERR_NORESPONSE;
state->state = TFTP_STATE_FIN;
return result;
}
if(data->state.upload) {
/* If we are uploading, send an WRQ */
setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
state->data->req.upload_fromhere =
(char *)state->spacket.data + 4;
if(data->state.infilesize != -1)
Curl_pgrsSetUploadSize(data, data->state.infilesize);
}
else {
/* If we are downloading, send an RRQ */
setpacketevent(&state->spacket, TFTP_EVENT_RRQ);
}
/* As RFC3617 describes the separator slash is not actually part of the
file name so we skip the always-present first letter of the path
string. */
result = Curl_urldecode(&state->data->state.up.path[1], 0,
&filename, NULL, REJECT_ZERO);
if(result)
return result;
if(strlen(filename) > (state->blksize - strlen(mode) - 4)) {
failf(data, "TFTP file name too long");
free(filename);
return CURLE_TFTP_ILLEGAL; /* too long file name field */
}
msnprintf((char *)state->spacket.data + 2,
state->blksize,
"%s%c%s%c", filename, '\0', mode, '\0');
sbytes = 4 + strlen(filename) + strlen(mode);
/* optional addition of TFTP options */
if(!data->set.tftp_no_options) {
char buf[64];
/* add tsize option */
if(data->state.upload && (data->state.infilesize != -1))
msnprintf(buf, sizeof(buf), "%" CURL_FORMAT_CURL_OFF_T,
data->state.infilesize);
else
strcpy(buf, "0"); /* the destination is large enough */
result = tftp_option_add(state, &sbytes,
(char *)state->spacket.data + sbytes,
TFTP_OPTION_TSIZE);
if(result == CURLE_OK)
result = tftp_option_add(state, &sbytes,
(char *)state->spacket.data + sbytes, buf);
/* add blksize option */
msnprintf(buf, sizeof(buf), "%d", state->requested_blksize);
if(result == CURLE_OK)
result = tftp_option_add(state, &sbytes,
(char *)state->spacket.data + sbytes,
TFTP_OPTION_BLKSIZE);
if(result == CURLE_OK)
result = tftp_option_add(state, &sbytes,
(char *)state->spacket.data + sbytes, buf);
/* add timeout option */
msnprintf(buf, sizeof(buf), "%d", state->retry_time);
if(result == CURLE_OK)
result = tftp_option_add(state, &sbytes,
(char *)state->spacket.data + sbytes,
TFTP_OPTION_INTERVAL);
if(result == CURLE_OK)
result = tftp_option_add(state, &sbytes,
(char *)state->spacket.data + sbytes, buf);
if(result != CURLE_OK) {
failf(data, "TFTP buffer too small for options");
free(filename);
return CURLE_TFTP_ILLEGAL;
}
}
/* the typecase for the 3rd argument is mostly for systems that do
not have a size_t argument, like older unixes that want an 'int' */
senddata = sendto(state->sockfd, (void *)state->spacket.data,
(SEND_TYPE_ARG3)sbytes, 0,
&data->conn->remote_addr->sa_addr,
data->conn->remote_addr->addrlen);
if(senddata != (ssize_t)sbytes) {
char buffer[STRERROR_LEN];
failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
}
free(filename);
break;
case TFTP_EVENT_OACK:
if(data->state.upload) {
result = tftp_connect_for_tx(state, event);
}
else {
result = tftp_connect_for_rx(state, event);
}
break;
case TFTP_EVENT_ACK: /* Connected for transmit */
result = tftp_connect_for_tx(state, event);
break;
case TFTP_EVENT_DATA: /* Connected for receive */
result = tftp_connect_for_rx(state, event);
break;
case TFTP_EVENT_ERROR:
state->state = TFTP_STATE_FIN;
break;
default:
failf(state->data, "tftp_send_first: internal error");
break;
}
return result;
}
/* the next blocknum is x + 1 but it needs to wrap at an unsigned 16bit
boundary */
#define NEXT_BLOCKNUM(x) (((x) + 1)&0xffff)
/**********************************************************
*
* tftp_rx
*
* Event handler for the RX state
*
**********************************************************/
static CURLcode tftp_rx(struct tftp_state_data *state,
tftp_event_t event)
{
ssize_t sbytes;
int rblock;
struct Curl_easy *data = state->data;
char buffer[STRERROR_LEN];
switch(event) {
case TFTP_EVENT_DATA:
/* Is this the block we expect? */
rblock = getrpacketblock(&state->rpacket);
if(NEXT_BLOCKNUM(state->block) == rblock) {
/* This is the expected block. Reset counters and ACK it. */
state->retries = 0;
}
else if(state->block == rblock) {
/* This is the last recently received block again. Log it and ACK it
again. */
infof(data, "Received last DATA packet block %d again.", rblock);
}
else {
/* totally unexpected, just log it */
infof(data,
"Received unexpected DATA packet block %d, expecting block %d",
rblock, NEXT_BLOCKNUM(state->block));
break;
}
/* ACK this block. */
state->block = (unsigned short)rblock;
setpacketevent(&state->spacket, TFTP_EVENT_ACK);
setpacketblock(&state->spacket, state->block);
sbytes = sendto(state->sockfd, (void *)state->spacket.data,
4, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
if(sbytes < 0) {
failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
return CURLE_SEND_ERROR;
}
/* Check if completed (That is, a less than full packet is received) */
if(state->rbytes < (ssize_t)state->blksize + 4) {
state->state = TFTP_STATE_FIN;
}
else {
state->state = TFTP_STATE_RX;
}
time(&state->rx_time);
break;
case TFTP_EVENT_OACK:
/* ACK option acknowledgement so we can move on to data */
state->block = 0;
state->retries = 0;
setpacketevent(&state->spacket, TFTP_EVENT_ACK);
setpacketblock(&state->spacket, state->block);
sbytes = sendto(state->sockfd, (void *)state->spacket.data,
4, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
if(sbytes < 0) {
failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
return CURLE_SEND_ERROR;
}
/* we're ready to RX data */
state->state = TFTP_STATE_RX;
time(&state->rx_time);
break;
case TFTP_EVENT_TIMEOUT:
/* Increment the retry count and fail if over the limit */
state->retries++;
infof(data,
"Timeout waiting for block %d ACK. Retries = %d",
NEXT_BLOCKNUM(state->block), state->retries);
if(state->retries > state->retry_max) {
state->error = TFTP_ERR_TIMEOUT;
state->state = TFTP_STATE_FIN;
}
else {
/* Resend the previous ACK */
sbytes = sendto(state->sockfd, (void *)state->spacket.data,
4, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
if(sbytes<0) {
failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
return CURLE_SEND_ERROR;
}
}
break;
case TFTP_EVENT_ERROR:
setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
setpacketblock(&state->spacket, state->block);
(void)sendto(state->sockfd, (void *)state->spacket.data,
4, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
/* don't bother with the return code, but if the socket is still up we
* should be a good TFTP client and let the server know we're done */
state->state = TFTP_STATE_FIN;
break;
default:
failf(data, "%s", "tftp_rx: internal error");
return CURLE_TFTP_ILLEGAL; /* not really the perfect return code for
this */
}
return CURLE_OK;
}
/**********************************************************
*
* tftp_tx
*
* Event handler for the TX state
*
**********************************************************/
static CURLcode tftp_tx(struct tftp_state_data *state, tftp_event_t event)
{
struct Curl_easy *data = state->data;
ssize_t sbytes;
CURLcode result = CURLE_OK;
struct SingleRequest *k = &data->req;
size_t cb; /* Bytes currently read */
char buffer[STRERROR_LEN];
switch(event) {
case TFTP_EVENT_ACK:
case TFTP_EVENT_OACK:
if(event == TFTP_EVENT_ACK) {
/* Ack the packet */
int rblock = getrpacketblock(&state->rpacket);
if(rblock != state->block &&
/* There's a bug in tftpd-hpa that causes it to send us an ack for
* 65535 when the block number wraps to 0. So when we're expecting
* 0, also accept 65535. See
* https://www.syslinux.org/archives/2010-September/015612.html
* */
!(state->block == 0 && rblock == 65535)) {
/* This isn't the expected block. Log it and up the retry counter */
infof(data, "Received ACK for block %d, expecting %d",
rblock, state->block);
state->retries++;
/* Bail out if over the maximum */
if(state->retries>state->retry_max) {
failf(data, "tftp_tx: giving up waiting for block %d ack",
state->block);
result = CURLE_SEND_ERROR;
}
else {
/* Re-send the data packet */
sbytes = sendto(state->sockfd, (void *)state->spacket.data,
4 + state->sbytes, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
/* Check all sbytes were sent */
if(sbytes<0) {
failf(data, "%s", Curl_strerror(SOCKERRNO,
buffer, sizeof(buffer)));
result = CURLE_SEND_ERROR;
}
}
return result;
}
/* This is the expected packet. Reset the counters and send the next
block */
time(&state->rx_time);
state->block++;
}
else
state->block = 1; /* first data block is 1 when using OACK */
state->retries = 0;
setpacketevent(&state->spacket, TFTP_EVENT_DATA);
setpacketblock(&state->spacket, state->block);
if(state->block > 1 && state->sbytes < state->blksize) {
state->state = TFTP_STATE_FIN;
return CURLE_OK;
}
/* TFTP considers data block size < 512 bytes as an end of session. So
* in some cases we must wait for additional data to build full (512 bytes)
* data block.
* */
state->sbytes = 0;
state->data->req.upload_fromhere = (char *)state->spacket.data + 4;
do {
result = Curl_fillreadbuffer(data, state->blksize - state->sbytes, &cb);
if(result)
return result;
state->sbytes += (int)cb;
state->data->req.upload_fromhere += cb;
} while(state->sbytes < state->blksize && cb);
sbytes = sendto(state->sockfd, (void *) state->spacket.data,
4 + state->sbytes, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
/* Check all sbytes were sent */
if(sbytes<0) {
failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
return CURLE_SEND_ERROR;
}
/* Update the progress meter */
k->writebytecount += state->sbytes;
Curl_pgrsSetUploadCounter(data, k->writebytecount);
break;
case TFTP_EVENT_TIMEOUT:
/* Increment the retry counter and log the timeout */
state->retries++;
infof(data, "Timeout waiting for block %d ACK. "
" Retries = %d", NEXT_BLOCKNUM(state->block), state->retries);
/* Decide if we've had enough */
if(state->retries > state->retry_max) {
state->error = TFTP_ERR_TIMEOUT;
state->state = TFTP_STATE_FIN;
}
else {
/* Re-send the data packet */
sbytes = sendto(state->sockfd, (void *)state->spacket.data,
4 + state->sbytes, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
/* Check all sbytes were sent */
if(sbytes<0) {
failf(data, "%s", Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
return CURLE_SEND_ERROR;
}
/* since this was a re-send, we remain at the still byte position */
Curl_pgrsSetUploadCounter(data, k->writebytecount);
}
break;
case TFTP_EVENT_ERROR:
state->state = TFTP_STATE_FIN;
setpacketevent(&state->spacket, TFTP_EVENT_ERROR);
setpacketblock(&state->spacket, state->block);
(void)sendto(state->sockfd, (void *)state->spacket.data, 4, SEND_4TH_ARG,
(struct sockaddr *)&state->remote_addr,
state->remote_addrlen);
/* don't bother with the return code, but if the socket is still up we
* should be a good TFTP client and let the server know we're done */
state->state = TFTP_STATE_FIN;
break;
default:
failf(data, "tftp_tx: internal error, event: %i", (int)(event));
break;
}
return result;
}
/**********************************************************
*
* tftp_translate_code
*
* Translate internal error codes to CURL error codes
*
**********************************************************/
static CURLcode tftp_translate_code(tftp_error_t error)
{
CURLcode result = CURLE_OK;
if(error != TFTP_ERR_NONE) {
switch(error) {
case TFTP_ERR_NOTFOUND:
result = CURLE_TFTP_NOTFOUND;
break;
case TFTP_ERR_PERM:
result = CURLE_TFTP_PERM;
break;
case TFTP_ERR_DISKFULL:
result = CURLE_REMOTE_DISK_FULL;
break;
case TFTP_ERR_UNDEF:
case TFTP_ERR_ILLEGAL:
result = CURLE_TFTP_ILLEGAL;
break;
case TFTP_ERR_UNKNOWNID:
result = CURLE_TFTP_UNKNOWNID;
break;
case TFTP_ERR_EXISTS:
result = CURLE_REMOTE_FILE_EXISTS;
break;
case TFTP_ERR_NOSUCHUSER:
result = CURLE_TFTP_NOSUCHUSER;
break;
case TFTP_ERR_TIMEOUT:
result = CURLE_OPERATION_TIMEDOUT;
break;
case TFTP_ERR_NORESPONSE:
result = CURLE_COULDNT_CONNECT;
break;
default:
result = CURLE_ABORTED_BY_CALLBACK;
break;
}
}
else
result = CURLE_OK;
return result;
}
/**********************************************************
*
* tftp_state_machine
*
* The tftp state machine event dispatcher
*
**********************************************************/
static CURLcode tftp_state_machine(struct tftp_state_data *state,
tftp_event_t event)
{
CURLcode result = CURLE_OK;
struct Curl_easy *data = state->data;
switch(state->state) {
case TFTP_STATE_START:
DEBUGF(infof(data, "TFTP_STATE_START"));
result = tftp_send_first(state, event);
break;
case TFTP_STATE_RX:
DEBUGF(infof(data, "TFTP_STATE_RX"));
result = tftp_rx(state, event);
break;
case TFTP_STATE_TX:
DEBUGF(infof(data, "TFTP_STATE_TX"));
result = tftp_tx(state, event);
break;
case TFTP_STATE_FIN:
infof(data, "%s", "TFTP finished");
break;
default:
DEBUGF(infof(data, "STATE: %d", state->state));
failf(data, "%s", "Internal state machine error");
result = CURLE_TFTP_ILLEGAL;
break;
}
return result;
}
/**********************************************************
*
* tftp_disconnect
*
* The disconnect callback
*
**********************************************************/
static CURLcode tftp_disconnect(struct Curl_easy *data,
struct connectdata *conn, bool dead_connection)
{
struct tftp_state_data *state = conn->proto.tftpc;
(void) data;
(void) dead_connection;
/* done, free dynamically allocated pkt buffers */
if(state) {
Curl_safefree(state->rpacket.data);
Curl_safefree(state->spacket.data);
free(state);
}
return CURLE_OK;
}
/**********************************************************
*
* tftp_connect
*
* The connect callback
*
**********************************************************/
static CURLcode tftp_connect(struct Curl_easy *data, bool *done)
{
struct tftp_state_data *state;
int blksize;
int need_blksize;
struct connectdata *conn = data->conn;
blksize = TFTP_BLKSIZE_DEFAULT;
state = conn->proto.tftpc = calloc(1, sizeof(struct tftp_state_data));
if(!state)
return CURLE_OUT_OF_MEMORY;
/* alloc pkt buffers based on specified blksize */
if(data->set.tftp_blksize)
/* range checked when set */
blksize = (int)data->set.tftp_blksize;
need_blksize = blksize;
/* default size is the fallback when no OACK is received */
if(need_blksize < TFTP_BLKSIZE_DEFAULT)
need_blksize = TFTP_BLKSIZE_DEFAULT;
if(!state->rpacket.data) {
state->rpacket.data = calloc(1, need_blksize + 2 + 2);
if(!state->rpacket.data)
return CURLE_OUT_OF_MEMORY;
}
if(!state->spacket.data) {
state->spacket.data = calloc(1, need_blksize + 2 + 2);
if(!state->spacket.data)
return CURLE_OUT_OF_MEMORY;
}
/* we don't keep TFTP connections up basically because there's none or very
* little gain for UDP */
connclose(conn, "TFTP");
state->data = data;
state->sockfd = conn->sock[FIRSTSOCKET];
state->state = TFTP_STATE_START;
state->error = TFTP_ERR_NONE;
state->blksize = TFTP_BLKSIZE_DEFAULT; /* Unless updated by OACK response */
state->requested_blksize = blksize;
((struct sockaddr *)&state->local_addr)->sa_family =
(CURL_SA_FAMILY_T)(conn->remote_addr->family);
tftp_set_timeouts(state);
if(!conn->bits.bound) {
/* If not already bound, bind to any interface, random UDP port. If it is
* reused or a custom local port was desired, this has already been done!
*
* We once used the size of the local_addr struct as the third argument
* for bind() to better work with IPv6 or whatever size the struct could
* have, but we learned that at least Tru64, AIX and IRIX *requires* the
* size of that argument to match the exact size of a 'sockaddr_in' struct
* when running IPv4-only.
*
* Therefore we use the size from the address we connected to, which we
* assume uses the same IP version and thus hopefully this works for both
* IPv4 and IPv6...
*/
int rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr,
conn->remote_addr->addrlen);
if(rc) {
char buffer[STRERROR_LEN];
failf(data, "bind() failed; %s",
Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
return CURLE_COULDNT_CONNECT;
}
conn->bits.bound = TRUE;
}
Curl_pgrsStartNow(data);
*done = TRUE;
return CURLE_OK;
}
/**********************************************************
*
* tftp_done
*
* The done callback
*
**********************************************************/
static CURLcode tftp_done(struct Curl_easy *data, CURLcode status,
bool premature)
{
CURLcode result = CURLE_OK;
struct connectdata *conn = data->conn;
struct tftp_state_data *state = conn->proto.tftpc;
(void)status; /* unused */
(void)premature; /* not used */
if(Curl_pgrsDone(data))
return CURLE_ABORTED_BY_CALLBACK;
/* If we have encountered an error */
if(state)
result = tftp_translate_code(state->error);
return result;
}
/**********************************************************
*
* tftp_getsock
*
* The getsock callback
*
**********************************************************/
static int tftp_getsock(struct Curl_easy *data,
struct connectdata *conn, curl_socket_t *socks)
{
(void)data;
socks[0] = conn->sock[FIRSTSOCKET];
return GETSOCK_READSOCK(0);
}
/**********************************************************
*
* tftp_receive_packet
*
* Called once select fires and data is ready on the socket
*
**********************************************************/
static CURLcode tftp_receive_packet(struct Curl_easy *data)
{
struct Curl_sockaddr_storage fromaddr;
curl_socklen_t fromlen;
CURLcode result = CURLE_OK;
struct connectdata *conn = data->conn;
struct tftp_state_data *state = conn->proto.tftpc;
/* Receive the packet */
fromlen = sizeof(fromaddr);
state->rbytes = (int)recvfrom(state->sockfd,
(void *)state->rpacket.data,
state->blksize + 4,
0,
(struct sockaddr *)&fromaddr,
&fromlen);
if(state->remote_addrlen == 0) {
memcpy(&state->remote_addr, &fromaddr, fromlen);
state->remote_addrlen = fromlen;
}
/* Sanity check packet length */
if(state->rbytes < 4) {
failf(data, "Received too short packet");
/* Not a timeout, but how best to handle it? */
state->event = TFTP_EVENT_TIMEOUT;
}
else {
/* The event is given by the TFTP packet time */
unsigned short event = getrpacketevent(&state->rpacket);
state->event = (tftp_event_t)event;
switch(state->event) {
case TFTP_EVENT_DATA:
/* Don't pass to the client empty or retransmitted packets */
if(state->rbytes > 4 &&
(NEXT_BLOCKNUM(state->block) == getrpacketblock(&state->rpacket))) {
result = Curl_client_write(data, CLIENTWRITE_BODY,
(char *)state->rpacket.data + 4,
state->rbytes-4);
if(result) {
tftp_state_machine(state, TFTP_EVENT_ERROR);
return result;
}
}
break;
case TFTP_EVENT_ERROR:
{
unsigned short error = getrpacketblock(&state->rpacket);
char *str = (char *)state->rpacket.data + 4;
size_t strn = state->rbytes - 4;
state->error = (tftp_error_t)error;
if(tftp_strnlen(str, strn) < strn)
infof(data, "TFTP error: %s", str);
break;
}
case TFTP_EVENT_ACK:
break;
case TFTP_EVENT_OACK:
result = tftp_parse_option_ack(state,
(const char *)state->rpacket.data + 2,
state->rbytes-2);
if(result)
return result;
break;
case TFTP_EVENT_RRQ:
case TFTP_EVENT_WRQ:
default:
failf(data, "%s", "Internal error: Unexpected packet");
break;
}
/* Update the progress meter */
if(Curl_pgrsUpdate(data)) {
tftp_state_machine(state, TFTP_EVENT_ERROR);
return CURLE_ABORTED_BY_CALLBACK;
}
}
return result;
}
/**********************************************************
*
* tftp_state_timeout
*
* Check if timeouts have been reached
*
**********************************************************/
static timediff_t tftp_state_timeout(struct Curl_easy *data,
tftp_event_t *event)
{
time_t current;
struct connectdata *conn = data->conn;
struct tftp_state_data *state = conn->proto.tftpc;
timediff_t timeout_ms;
if(event)
*event = TFTP_EVENT_NONE;
timeout_ms = Curl_timeleft(state->data, NULL,
(state->state == TFTP_STATE_START));
if(timeout_ms < 0) {
state->error = TFTP_ERR_TIMEOUT;
state->state = TFTP_STATE_FIN;
return 0;
}
time(&current);
if(current > state->rx_time + state->retry_time) {
if(event)
*event = TFTP_EVENT_TIMEOUT;
time(&state->rx_time); /* update even though we received nothing */
}
return timeout_ms;
}
/**********************************************************
*
* tftp_multi_statemach
*
* Handle single RX socket event and return
*
**********************************************************/
static CURLcode tftp_multi_statemach(struct Curl_easy *data, bool *done)
{
tftp_event_t event;
CURLcode result = CURLE_OK;
struct connectdata *conn = data->conn;
struct tftp_state_data *state = conn->proto.tftpc;
timediff_t timeout_ms = tftp_state_timeout(data, &event);
*done = FALSE;
if(timeout_ms < 0) {
failf(data, "TFTP response timeout");
return CURLE_OPERATION_TIMEDOUT;
}
if(event != TFTP_EVENT_NONE) {
result = tftp_state_machine(state, event);
if(result)
return result;
*done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
if(*done)
/* Tell curl we're done */
Curl_setup_transfer(data, -1, -1, FALSE, -1);
}
else {
/* no timeouts to handle, check our socket */
int rc = SOCKET_READABLE(state->sockfd, 0);
if(rc == -1) {
/* bail out */
int error = SOCKERRNO;
char buffer[STRERROR_LEN];
failf(data, "%s", Curl_strerror(error, buffer, sizeof(buffer)));
state->event = TFTP_EVENT_ERROR;
}
else if(rc) {
result = tftp_receive_packet(data);
if(result)
return result;
result = tftp_state_machine(state, state->event);
if(result)
return result;
*done = (state->state == TFTP_STATE_FIN) ? TRUE : FALSE;
if(*done)
/* Tell curl we're done */
Curl_setup_transfer(data, -1, -1, FALSE, -1);
}
/* if rc == 0, then select() timed out */
}
return result;
}
/**********************************************************
*
* tftp_doing
*
* Called from multi.c while DOing
*
**********************************************************/
static CURLcode tftp_doing(struct Curl_easy *data, bool *dophase_done)
{
CURLcode result;
result = tftp_multi_statemach(data, dophase_done);
if(*dophase_done) {
DEBUGF(infof(data, "DO phase is complete"));
}
else if(!result) {
/* The multi code doesn't have this logic for the DOING state so we
provide it for TFTP since it may do the entire transfer in this
state. */
if(Curl_pgrsUpdate(data))
result = CURLE_ABORTED_BY_CALLBACK;
else
result = Curl_speedcheck(data, Curl_now());
}
return result;
}
/**********************************************************
*
* tftp_perform
*
* Entry point for transfer from tftp_do, starts state mach
*
**********************************************************/
static CURLcode tftp_perform(struct Curl_easy *data, bool *dophase_done)
{
CURLcode result = CURLE_OK;
struct connectdata *conn = data->conn;
struct tftp_state_data *state = conn->proto.tftpc;
*dophase_done = FALSE;
result = tftp_state_machine(state, TFTP_EVENT_INIT);
if((state->state == TFTP_STATE_FIN) || result)
return result;
tftp_multi_statemach(data, dophase_done);
if(*dophase_done)
DEBUGF(infof(data, "DO phase is complete"));
return result;
}
/**********************************************************
*
* tftp_do
*
* The do callback
*
* This callback initiates the TFTP transfer
*
**********************************************************/
static CURLcode tftp_do(struct Curl_easy *data, bool *done)
{
struct tftp_state_data *state;
CURLcode result;
struct connectdata *conn = data->conn;
*done = FALSE;
if(!conn->proto.tftpc) {
result = tftp_connect(data, done);
if(result)
return result;
}
state = conn->proto.tftpc;
if(!state)
return CURLE_TFTP_ILLEGAL;
result = tftp_perform(data, done);
/* If tftp_perform() returned an error, use that for return code. If it
was OK, see if tftp_translate_code() has an error. */
if(!result)
/* If we have encountered an internal tftp error, translate it. */
result = tftp_translate_code(state->error);
return result;
}
static CURLcode tftp_setup_connection(struct Curl_easy *data,
struct connectdata *conn)
{
char *type;
conn->transport = TRNSPRT_UDP;
/* TFTP URLs support an extension like ";mode=<typecode>" that
* we'll try to get now! */
type = strstr(data->state.up.path, ";mode=");
if(!type)
type = strstr(conn->host.rawalloc, ";mode=");
if(type) {
char command;
*type = 0; /* it was in the middle of the hostname */
command = Curl_raw_toupper(type[6]);
switch(command) {
case 'A': /* ASCII mode */
case 'N': /* NETASCII mode */
data->state.prefer_ascii = TRUE;
break;
case 'O': /* octet mode */
case 'I': /* binary mode */
default:
/* switch off ASCII */
data->state.prefer_ascii = FALSE;
break;
}
}
return CURLE_OK;
}
#endif
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