/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2021, Daniel Stenberg, , 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. * ***************************************************************************/ #include "curl_setup.h" #ifndef CURL_DISABLE_TFTP #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_NETDB_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #ifdef HAVE_NET_IF_H #include #endif #ifdef HAVE_SYS_IOCTL_H #include #endif #ifdef HAVE_SYS_PARAM_H #include #endif #include "urldata.h" #include #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; 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 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; 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 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 */ CURLPROTO_TFTP, /* family */ 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(struct tftp_state_data *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(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->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(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->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(struct tftp_state_data *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(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->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, 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->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(struct tftp_state_data *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(struct tftp_state_data *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(struct tftp_state_data *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) { struct tftp_state_data *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) { struct tftp_state_data *state; int blksize; int need_blksize; 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(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; struct tftp_state_data *state = 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; struct tftp_state_data *state = 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(tftp_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; struct tftp_state_data *state = conn->proto.tftpc; if(event) *event = TFTP_EVENT_NONE; time(¤t); 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; struct tftp_state_data *state = 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; 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(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) { struct tftp_state_data *state; CURLcode result; *done = FALSE; if(!conn->proto.tftpc) { result = tftp_connect(conn, done); if(result) return result; } state = 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=" 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