--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/tftp.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,1423 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, 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.haxx.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.
+ *
+ ***************************************************************************/
+
+#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 "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_BLKSIZE_MIN 8
+#define TFTP_BLKSIZE_MAX 65464
+#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;
+
+typedef struct tftp_packet {
+  unsigned char *data;
+} tftp_packet_t;
+
+typedef struct tftp_state_data {
+  tftp_state_t    state;
+  tftp_mode_t     mode;
+  tftp_error_t    error;
+  tftp_event_t    event;
+  struct connectdata      *conn;
+  curl_socket_t   sockfd;
+  int             retries;
+  int             retry_time;
+  int             retry_max;
+  time_t          start_time;
+  time_t          max_time;
+  time_t          rx_time;
+  unsigned short  block;
+  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;
+  tftp_packet_t   rpacket;
+  tftp_packet_t   spacket;
+} tftp_state_data_t;
+
+
+/* Forward declarations */
+static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event);
+static CURLcode tftp_tx(tftp_state_data_t *state, tftp_event_t event);
+static CURLcode tftp_connect(struct connectdata *conn, bool *done);
+static CURLcode tftp_disconnect(struct connectdata *conn,
+                                bool dead_connection);
+static CURLcode tftp_do(struct connectdata *conn, bool *done);
+static CURLcode tftp_done(struct connectdata *conn,
+                          CURLcode, bool premature);
+static CURLcode tftp_setup_connection(struct connectdata * conn);
+static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done);
+static CURLcode tftp_doing(struct connectdata *conn, bool *dophase_done);
+static int tftp_getsock(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,                            /* readwrite */
+  ZERO_NULL,                            /* connection_check */
+  PORT_TFTP,                            /* defport */
+  CURLPROTO_TFTP,                       /* protocol */
+  PROTOPT_NONE | 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(tftp_state_data_t *state)
+{
+  time_t maxtime, timeout;
+  timediff_t timeout_ms;
+  bool start = (state->state == TFTP_STATE_START) ? TRUE : FALSE;
+
+  time(&state->start_time);
+
+  /* Compute drop-dead time */
+  timeout_ms = Curl_timeleft(state->conn->data, NULL, start);
+
+  if(timeout_ms < 0) {
+    /* time-out, bail out, go home */
+    failf(state->conn->data, "Connection time-out");
+    return CURLE_OPERATION_TIMEDOUT;
+  }
+
+  if(start) {
+
+    maxtime = (time_t)(timeout_ms + 500) / 1000;
+    state->max_time = state->start_time + maxtime;
+
+    /* Set per-block timeout to total */
+    timeout = maxtime;
+
+    /* Average restart after 5 seconds */
+    state->retry_max = (int)timeout/5;
+
+    if(state->retry_max < 1)
+      /* avoid division by zero below */
+      state->retry_max = 1;
+
+    /* Compute the re-start interval to suit the timeout */
+    state->retry_time = (int)timeout/state->retry_max;
+    if(state->retry_time<1)
+      state->retry_time = 1;
+
+  }
+  else {
+    if(timeout_ms > 0)
+      maxtime = (time_t)(timeout_ms + 500) / 1000;
+    else
+      maxtime = 3600;
+
+    state->max_time = state->start_time + maxtime;
+
+    /* 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->conn->data,
+        "set timeouts for state %d; Total %ld, retry %d maxtry %d\n",
+        (int)state->state, (long)(state->max_time-state->start_time),
+        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(tftp_packet_t *packet, unsigned short num)
+{
+  packet->data[0] = (unsigned char)(num >> 8);
+  packet->data[1] = (unsigned char)(num & 0xff);
+}
+
+
+static void setpacketblock(tftp_packet_t *packet, unsigned short num)
+{
+  packet->data[2] = (unsigned char)(num >> 8);
+  packet->data[3] = (unsigned char)(num & 0xff);
+}
+
+static unsigned short getrpacketevent(const tftp_packet_t *packet)
+{
+  return (unsigned short)((packet->data[0] << 8) | packet->data[1]);
+}
+
+static unsigned short getrpacketblock(const tftp_packet_t *packet)
+{
+  return (unsigned short)((packet->data[2] << 8) | packet->data[3]);
+}
+
+static size_t Curl_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 = Curl_strnlen(buf, len);
+  loc++; /* NULL term */
+
+  if(loc >= len)
+    return NULL;
+  *option = buf;
+
+  loc += Curl_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(tftp_state_data_t *state,
+                                      const char *ptr, int len)
+{
+  const char *tmp = ptr;
+  struct Curl_easy *data = state->conn->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 == NULL) {
+      failf(data, "Malformed ACK packet, rejecting");
+      return CURLE_TFTP_ILLEGAL;
+    }
+
+    infof(data, "got option=(%s) value=(%s)\n", option, value);
+
+    if(checkprefix(option, TFTP_OPTION_BLKSIZE)) {
+      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)\n", "blksize parsed from OACK",
+            state->blksize, "requested", state->requested_blksize);
+    }
+    else if(checkprefix(option, TFTP_OPTION_TSIZE)) {
+      long tsize = 0;
+
+      tsize = strtol(value, NULL, 10);
+      infof(data, "%s (%ld)\n", "tsize parsed from OACK", tsize);
+
+      /* tsize should be ignored on upload: Who cares about the size of the
+         remote file? */
+      if(!data->set.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(tftp_state_data_t *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(tftp_state_data_t *state,
+                                    tftp_event_t event)
+{
+  CURLcode result;
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+  struct Curl_easy *data = state->conn->data;
+
+  infof(data, "%s\n", "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(tftp_state_data_t *state,
+                                    tftp_event_t event)
+{
+  CURLcode result;
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+  struct Curl_easy *data = state->conn->data;
+
+  infof(data, "%s\n", "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(tftp_state_data_t *state, tftp_event_t event)
+{
+  size_t sbytes;
+  ssize_t senddata;
+  const char *mode = "octet";
+  char *filename;
+  struct Curl_easy *data = state->conn->data;
+  CURLcode result = CURLE_OK;
+
+  /* Set ascii mode if -B flag was used */
+  if(data->set.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->set.upload) {
+      /* If we are uploading, send an WRQ */
+      setpacketevent(&state->spacket, TFTP_EVENT_WRQ);
+      state->conn->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(data, &state->conn->data->state.up.path[1], 0,
+                            &filename, NULL, FALSE);
+    if(result)
+      return result;
+
+    if(strlen(filename) > (state->blksize - strlen(mode) - 4)) {
+      failf(data, "TFTP file name too long\n");
+      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->set.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,
+                      state->conn->ip_addr->ai_addr,
+                      state->conn->ip_addr->ai_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->set.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->conn->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(tftp_state_data_t *state, tftp_event_t event)
+{
+  ssize_t sbytes;
+  int rblock;
+  struct Curl_easy *data = state->conn->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.\n", rblock);
+    }
+    else {
+      /* totally unexpected, just log it */
+      infof(data,
+            "Received unexpected DATA packet block %d, expecting block %d\n",
+            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\n",
+          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(tftp_state_data_t *state, tftp_event_t event)
+{
+  struct Curl_easy *data = state->conn->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
+          * http://syslinux.zytor.com/archives/2010-September/015253.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\n",
+              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->conn->data->req.upload_fromhere = (char *)state->spacket.data + 4;
+    do {
+      result = Curl_fillreadbuffer(state->conn, state->blksize - state->sbytes,
+                                   &cb);
+      if(result)
+        return result;
+      state->sbytes += (int)cb;
+      state->conn->data->req.upload_fromhere += cb;
+    } while(state->sbytes < state->blksize && cb != 0);
+
+    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\n", 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(tftp_state_data_t *state,
+                                   tftp_event_t event)
+{
+  CURLcode result = CURLE_OK;
+  struct Curl_easy *data = state->conn->data;
+
+  switch(state->state) {
+  case TFTP_STATE_START:
+    DEBUGF(infof(data, "TFTP_STATE_START\n"));
+    result = tftp_send_first(state, event);
+    break;
+  case TFTP_STATE_RX:
+    DEBUGF(infof(data, "TFTP_STATE_RX\n"));
+    result = tftp_rx(state, event);
+    break;
+  case TFTP_STATE_TX:
+    DEBUGF(infof(data, "TFTP_STATE_TX\n"));
+    result = tftp_tx(state, event);
+    break;
+  case TFTP_STATE_FIN:
+    infof(data, "%s\n", "TFTP finished");
+    break;
+  default:
+    DEBUGF(infof(data, "STATE: %d\n", 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 connectdata *conn, bool dead_connection)
+{
+  tftp_state_data_t *state = conn->proto.tftpc;
+  (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 connectdata *conn, bool *done)
+{
+  tftp_state_data_t *state;
+  int blksize;
+  int need_blksize;
+
+  blksize = TFTP_BLKSIZE_DEFAULT;
+
+  state = conn->proto.tftpc = calloc(1, sizeof(tftp_state_data_t));
+  if(!state)
+    return CURLE_OUT_OF_MEMORY;
+
+  /* alloc pkt buffers based on specified blksize */
+  if(conn->data->set.tftp_blksize) {
+    blksize = (int)conn->data->set.tftp_blksize;
+    if(blksize > TFTP_BLKSIZE_MAX || blksize < TFTP_BLKSIZE_MIN)
+      return CURLE_TFTP_ILLEGAL;
+  }
+
+  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->conn = conn;
+  state->sockfd = state->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->ip_addr->ai_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->ip_addr->ai_addrlen);
+    if(rc) {
+      char buffer[STRERROR_LEN];
+      failf(conn->data, "bind() failed; %s",
+            Curl_strerror(SOCKERRNO, buffer, sizeof(buffer)));
+      return CURLE_COULDNT_CONNECT;
+    }
+    conn->bits.bound = TRUE;
+  }
+
+  Curl_pgrsStartNow(conn->data);
+
+  *done = TRUE;
+
+  return CURLE_OK;
+}
+
+/**********************************************************
+ *
+ * tftp_done
+ *
+ * The done callback
+ *
+ **********************************************************/
+static CURLcode tftp_done(struct connectdata *conn, CURLcode status,
+                          bool premature)
+{
+  CURLcode result = CURLE_OK;
+  tftp_state_data_t *state = (tftp_state_data_t *)conn->proto.tftpc;
+
+  (void)status; /* unused */
+  (void)premature; /* not used */
+
+  if(Curl_pgrsDone(conn))
+    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 connectdata *conn, curl_socket_t *socks)
+{
+  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 connectdata *conn)
+{
+  struct Curl_sockaddr_storage fromaddr;
+  curl_socklen_t        fromlen;
+  CURLcode              result = CURLE_OK;
+  struct Curl_easy  *data = conn->data;
+  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
+  struct SingleRequest  *k = &data->req;
+
+  /* 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(conn, CLIENTWRITE_BODY,
+                                   (char *)state->rpacket.data + 4,
+                                   state->rbytes-4);
+        if(result) {
+          tftp_state_machine(state, TFTP_EVENT_ERROR);
+          return result;
+        }
+        k->bytecount += state->rbytes-4;
+        Curl_pgrsSetDownloadCounter(data, (curl_off_t) k->bytecount);
+      }
+      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(Curl_strnlen(str, strn) < strn)
+        infof(data, "TFTP error: %s\n", 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(conn)) {
+      tftp_state_machine(state, TFTP_EVENT_ERROR);
+      return CURLE_ABORTED_BY_CALLBACK;
+    }
+  }
+  return result;
+}
+
+/**********************************************************
+ *
+ * tftp_state_timeout
+ *
+ * Check if timeouts have been reached
+ *
+ **********************************************************/
+static long tftp_state_timeout(struct connectdata *conn, tftp_event_t *event)
+{
+  time_t                current;
+  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
+
+  if(event)
+    *event = TFTP_EVENT_NONE;
+
+  time(&current);
+  if(current > state->max_time) {
+    DEBUGF(infof(conn->data, "timeout: %ld > %ld\n",
+                 (long)current, (long)state->max_time));
+    state->error = TFTP_ERR_TIMEOUT;
+    state->state = TFTP_STATE_FIN;
+    return 0;
+  }
+  if(current > state->rx_time + state->retry_time) {
+    if(event)
+      *event = TFTP_EVENT_TIMEOUT;
+    time(&state->rx_time); /* update even though we received nothing */
+  }
+
+  /* there's a typecast below here since 'time_t' may in fact be larger than
+     'long', but we estimate that a 'long' will still be able to hold number
+     of seconds even if "only" 32 bit */
+  return (long)(state->max_time - current);
+}
+
+/**********************************************************
+ *
+ * tftp_multi_statemach
+ *
+ * Handle single RX socket event and return
+ *
+ **********************************************************/
+static CURLcode tftp_multi_statemach(struct connectdata *conn, bool *done)
+{
+  tftp_event_t          event;
+  CURLcode              result = CURLE_OK;
+  struct Curl_easy  *data = conn->data;
+  tftp_state_data_t     *state = (tftp_state_data_t *)conn->proto.tftpc;
+  long                  timeout_ms = tftp_state_timeout(conn, &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 != 0) {
+      result = tftp_receive_packet(conn);
+      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 connectdata *conn, bool *dophase_done)
+{
+  CURLcode result;
+  result = tftp_multi_statemach(conn, dophase_done);
+
+  if(*dophase_done) {
+    DEBUGF(infof(conn->data, "DO phase is complete\n"));
+  }
+  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(conn))
+      result = CURLE_ABORTED_BY_CALLBACK;
+    else
+      result = Curl_speedcheck(conn->data, Curl_now());
+  }
+  return result;
+}
+
+/**********************************************************
+ *
+ * tftp_peform
+ *
+ * Entry point for transfer from tftp_do, sarts state mach
+ *
+ **********************************************************/
+static CURLcode tftp_perform(struct connectdata *conn, bool *dophase_done)
+{
+  CURLcode              result = CURLE_OK;
+  tftp_state_data_t     *state = (tftp_state_data_t *)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(conn, dophase_done);
+
+  if(*dophase_done)
+    DEBUGF(infof(conn->data, "DO phase is complete\n"));
+
+  return result;
+}
+
+
+/**********************************************************
+ *
+ * tftp_do
+ *
+ * The do callback
+ *
+ * This callback initiates the TFTP transfer
+ *
+ **********************************************************/
+
+static CURLcode tftp_do(struct connectdata *conn, bool *done)
+{
+  tftp_state_data_t *state;
+  CURLcode result;
+
+  *done = FALSE;
+
+  if(!conn->proto.tftpc) {
+    result = tftp_connect(conn, done);
+    if(result)
+      return result;
+  }
+
+  state = (tftp_state_data_t *)conn->proto.tftpc;
+  if(!state)
+    return CURLE_TFTP_ILLEGAL;
+
+  result = tftp_perform(conn, 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 connectdata * conn)
+{
+  struct Curl_easy *data = conn->data;
+  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->set.prefer_ascii = TRUE;
+      break;
+
+    case 'O': /* octet mode */
+    case 'I': /* binary mode */
+    default:
+      /* switch off ASCII */
+      data->set.prefer_ascii = FALSE;
+      break;
+    }
+  }
+
+  return CURLE_OK;
+}
+#endif