/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2007, 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 http://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. * * $Id: tftp.c,v 1.48 2007-06-12 08:15:02 bagder Exp $ ***************************************************************************/ #include "setup.h" #ifndef CURL_DISABLE_TFTP /* -- WIN32 approved -- */ #include #include #include #include #include #if defined(WIN32) #include #include #else #ifdef HAVE_SYS_SOCKET_H #include #endif #include #ifdef HAVE_SYS_TIME_H #include #endif #ifdef HAVE_UNISTD_H #include #endif #include #ifdef HAVE_ARPA_INET_H #include #endif #ifdef HAVE_NET_IF_H #include #endif #include #include #ifdef HAVE_SYS_PARAM_H #include #endif #endif /* WIN32 */ #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 "url.h" #define _MPRINTF_REPLACE /* use our functions only */ #include #include "memory.h" #include "select.h" /* The last #include file should be: */ #include "memdebug.h" /* RFC2348 allows the block size to be negotiated, but we don't support that */ #define TFTP_BLOCKSIZE 512 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_INIT=0, TFTP_EVENT_RRQ = 1, TFTP_EVENT_WRQ = 2, TFTP_EVENT_DATA = 3, TFTP_EVENT_ACK = 4, TFTP_EVENT_ERROR = 5, 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, TFTP_ERR_TIMEOUT, TFTP_ERR_NORESPONSE } tftp_error_t; typedef struct tftp_packet { unsigned char data[2 + 2 + TFTP_BLOCKSIZE]; } tftp_packet_t; typedef struct tftp_state_data { tftp_state_t state; tftp_mode_t mode; tftp_error_t error; struct connectdata *conn; curl_socket_t sockfd; int retries; int retry_time; int retry_max; time_t start_time; time_t max_time; unsigned short block; struct Curl_sockaddr_storage local_addr; struct Curl_sockaddr_storage remote_addr; socklen_t remote_addrlen; int rbytes; int sbytes; 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) ; void tftp_set_timeouts(tftp_state_data_t *state) ; /********************************************************** * * 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 * * **********************************************************/ void tftp_set_timeouts(tftp_state_data_t *state) { struct SessionHandle *data = state->conn->data; time_t maxtime, timeout; time(&state->start_time); if(state->state == TFTP_STATE_START) { /* Compute drop-dead time */ maxtime = (time_t)(data->set.connecttimeout/1000L? data->set.connecttimeout/1000L:30); state->max_time = state->start_time+maxtime; /* Set per-block timeout to total */ timeout = maxtime ; /* Average restart after 5 seconds */ state->retry_max = 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 = timeout/state->retry_max; if(state->retry_time<1) state->retry_time=1; } else { /* Compute drop-dead time */ maxtime = (time_t)(data->set.timeout/1000L? data->set.timeout/1000L:3600); state->max_time = state->start_time+maxtime; /* Set per-block timeout to 10% of total */ timeout = maxtime/10 ; /* Average reposting an ACK after 15 seconds */ state->retry_max = timeout/15; } /* 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 = timeout/state->retry_max; if(state->retry_time<1) state->retry_time=1; infof(data, "set timeouts for state %d; Total %d, retry %d maxtry %d\n", state->state, (state->max_time-state->start_time), state->retry_time, state->retry_max); } /********************************************************** * * 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(tftp_packet_t *packet) { return (unsigned short)((packet->data[0] << 8) | packet->data[1]); } static unsigned short getrpacketblock(tftp_packet_t *packet) { return (unsigned short)((packet->data[2] << 8) | packet->data[3]); } static CURLcode tftp_send_first(tftp_state_data_t *state, tftp_event_t event) { int sbytes; const char *mode = "octet"; char *filename; struct SessionHandle *data = state->conn->data; CURLcode res = 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 res; } if(data->set.upload) { /* If we are uploading, send an WRQ */ setpacketevent(&state->spacket, TFTP_EVENT_WRQ); state->conn->data->reqdata.upload_fromhere = (char *)&state->spacket.data[4]; if(data->set.infilesize != -1) Curl_pgrsSetUploadSize(data, data->set.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. */ filename = curl_easy_unescape(data, &state->conn->data->reqdata.path[1], 0, NULL); if (!filename) return CURLE_OUT_OF_MEMORY; snprintf((char *)&state->spacket.data[2], TFTP_BLOCKSIZE, "%s%c%s%c", filename, '\0', mode, '\0'); sbytes = 4 + (int)strlen(filename) + (int)strlen(mode); sbytes = sendto(state->sockfd, (void *)&state->spacket, sbytes, 0, state->conn->ip_addr->ai_addr, state->conn->ip_addr->ai_addrlen); if(sbytes < 0) { failf(data, "%s\n", Curl_strerror(state->conn, SOCKERRNO)); } Curl_safefree(filename); break; case TFTP_EVENT_ACK: /* Connected for transmit */ infof(data, "%s\n", "Connected for transmit"); state->state = TFTP_STATE_TX; tftp_set_timeouts(state); return tftp_tx(state, event); case TFTP_EVENT_DATA: /* connected for receive */ infof(data, "%s\n", "Connected for receive"); state->state = TFTP_STATE_RX; tftp_set_timeouts(state); return tftp_rx(state, event); case TFTP_EVENT_ERROR: state->state = TFTP_STATE_FIN; break; default: failf(state->conn->data, "tftp_send_first: internal error\n"); break; } return res; } /********************************************************** * * tftp_rx * * Event handler for the RX state * **********************************************************/ static CURLcode tftp_rx(tftp_state_data_t *state, tftp_event_t event) { int sbytes; int rblock; struct SessionHandle *data = state->conn->data; switch(event) { case TFTP_EVENT_DATA: /* Is this the block we expect? */ rblock = getrpacketblock(&state->rpacket); if ((state->block+1) != rblock) { /* No, log it, up the retry count and fail if over the limit */ infof(data, "Received unexpected DATA packet block %d\n", rblock); state->retries++; if (state->retries>state->retry_max) { failf(data, "tftp_rx: giving up waiting for block %d\n", state->block+1); return CURLE_TFTP_ILLEGAL; } } /* This is the expected block. Reset counters and ACK it. */ state->block = (unsigned short)rblock; 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\n", Curl_strerror(state->conn, SOCKERRNO)); return CURLE_SEND_ERROR; } /* Check if completed (That is, a less than full packet is received) */ if (state->rbytes < (int)sizeof(state->spacket)){ state->state = TFTP_STATE_FIN; } else { state->state = TFTP_STATE_RX; } 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", 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, 4, SEND_4TH_ARG, (struct sockaddr *)&state->remote_addr, state->remote_addrlen); /* Check all sbytes were sent */ if(sbytes<0) { failf(data, "%s\n", Curl_strerror(state->conn, SOCKERRNO)); return CURLE_SEND_ERROR; } } break; case TFTP_EVENT_ERROR: state->state = TFTP_STATE_FIN; break; default: failf(data, "%s\n", "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 SessionHandle *data = state->conn->data; int sbytes; int rblock; CURLcode res = CURLE_OK; struct Curl_transfer_keeper *k = &data->reqdata.keep; switch(event) { case TFTP_EVENT_ACK: /* Ack the packet */ rblock = getrpacketblock(&state->rpacket); if(rblock != state->block) { /* 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); res = CURLE_SEND_ERROR; } else { /* Re-send the data packet */ sbytes = sendto(state->sockfd, (void *)&state->spacket, 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\n", Curl_strerror(state->conn, SOCKERRNO)); res = CURLE_SEND_ERROR; } } return res; } /* This is the expected packet. Reset the counters and send the next block */ state->block++; state->retries = 0; setpacketevent(&state->spacket, TFTP_EVENT_DATA); setpacketblock(&state->spacket, state->block); if(state->block > 1 && state->sbytes < TFTP_BLOCKSIZE) { state->state = TFTP_STATE_FIN; return CURLE_OK; } res = Curl_fillreadbuffer(state->conn, TFTP_BLOCKSIZE, &state->sbytes); if(res) return res; 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\n", Curl_strerror(state->conn, SOCKERRNO)); 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", 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, 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\n", Curl_strerror(state->conn, SOCKERRNO)); 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; break; default: failf(data, "%s\n", "tftp_tx: internal error"); break; } return res; } /********************************************************** * * tftp_state_machine * * The tftp state machine event dispatcher * **********************************************************/ static CURLcode tftp_state_machine(tftp_state_data_t *state, tftp_event_t event) { CURLcode res = CURLE_OK; struct SessionHandle *data = state->conn->data; switch(state->state) { case TFTP_STATE_START: DEBUGF(infof(data, "TFTP_STATE_START\n")); res = tftp_send_first(state, event); break; case TFTP_STATE_RX: DEBUGF(infof(data, "TFTP_STATE_RX\n")); res = tftp_rx(state, event); break; case TFTP_STATE_TX: DEBUGF(infof(data, "TFTP_STATE_TX\n")); res = 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\n", "Internal state machine error"); res = CURLE_TFTP_ILLEGAL; break; } return res; } /********************************************************** * * Curl_tftp_connect * * The connect callback * **********************************************************/ CURLcode Curl_tftp_connect(struct connectdata *conn, bool *done) { CURLcode code; tftp_state_data_t *state; int rc; state = conn->data->reqdata.proto.tftp = calloc(sizeof(tftp_state_data_t), 1); if(!state) return CURLE_OUT_OF_MEMORY; conn->bits.close = FALSE; /* keep it open if possible */ state->conn = conn; state->sockfd = state->conn->sock[FIRSTSOCKET]; state->state = TFTP_STATE_START; ((struct sockaddr *)&state->local_addr)->sa_family = (unsigned short)(conn->ip_addr->ai_family); tftp_set_timeouts(state); if(!conn->bits.reuse) { /* If not reused, bind to any interface, random UDP port. If it is reused, * 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... */ rc = bind(state->sockfd, (struct sockaddr *)&state->local_addr, conn->ip_addr->ai_addrlen); if(rc) { failf(conn->data, "bind() failed; %s\n", Curl_strerror(conn, SOCKERRNO)); return CURLE_COULDNT_CONNECT; } } Curl_pgrsStartNow(conn->data); *done = TRUE; code = CURLE_OK; return(code); } /********************************************************** * * Curl_tftp_done * * The done callback * **********************************************************/ CURLcode Curl_tftp_done(struct connectdata *conn, CURLcode status, bool premature) { (void)status; /* unused */ (void)premature; /* not used */ #if 0 free(conn->data->reqdata.proto.tftp); conn->data->reqdata.proto.tftp = NULL; #endif Curl_pgrsDone(conn); return CURLE_OK; } /********************************************************** * * Curl_tftp * * The do callback * * This callback handles the entire TFTP transfer * **********************************************************/ CURLcode Curl_tftp(struct connectdata *conn, bool *done) { struct SessionHandle *data = conn->data; tftp_state_data_t *state = (tftp_state_data_t *) conn->data->reqdata.proto.tftp; tftp_event_t event; CURLcode code; int rc; struct Curl_sockaddr_storage fromaddr; socklen_t fromlen; int check_time = 0; struct Curl_transfer_keeper *k = &data->reqdata.keep; *done = TRUE; /* Since connections can be re-used between SessionHandles, this might be a connection already existing but on a fresh SessionHandle struct so we must make sure we have a good 'struct TFTP' to play with. For new connections, the struct TFTP is allocated and setup in the Curl_tftp_connect() function. */ if(!state) { code = Curl_tftp_connect(conn, done); if(code) return code; state = (tftp_state_data_t *)conn->data->reqdata.proto.tftp; } code = Curl_readwrite_init(conn); if(code) return code; /* Run the TFTP State Machine */ for(code=tftp_state_machine(state, TFTP_EVENT_INIT); (state->state != TFTP_STATE_FIN) && (code == CURLE_OK); code=tftp_state_machine(state, event) ) { /* Wait until ready to read or timeout occurs */ rc=Curl_socket_ready(state->sockfd, CURL_SOCKET_BAD, state->retry_time * 1000); if(rc == -1) { /* bail out */ int error = SOCKERRNO; failf(data, "%s\n", Curl_strerror(conn, error)); event = TFTP_EVENT_ERROR; } else if (rc==0) { /* A timeout occured */ event = TFTP_EVENT_TIMEOUT; /* Force a look at transfer timeouts */ check_time = 0; } else { /* Receive the packet */ fromlen=sizeof(fromaddr); state->rbytes = recvfrom(state->sockfd, (void *)&state->rpacket, sizeof(state->rpacket), 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(conn->data, "Received too short packet\n"); /* Not a timeout, but how best to handle it? */ event = TFTP_EVENT_TIMEOUT; } else { /* The event is given by the TFTP packet time */ event = (tftp_event_t)getrpacketevent(&state->rpacket); switch(event) { case TFTP_EVENT_DATA: /* Don't pass to the client empty or retransmitted packets */ if (state->rbytes > 4 && ((state->block+1) == getrpacketblock(&state->rpacket))) { code = Curl_client_write(conn, CLIENTWRITE_BODY, (char *)&state->rpacket.data[4], state->rbytes-4); if(code) return code; k->bytecount += state->rbytes-4; Curl_pgrsSetDownloadCounter(data, (curl_off_t) k->bytecount); } break; case TFTP_EVENT_ERROR: state->error = (tftp_error_t)getrpacketblock(&state->rpacket); infof(conn->data, "%s\n", (char *)&state->rpacket.data[4]); break; case TFTP_EVENT_ACK: break; case TFTP_EVENT_RRQ: case TFTP_EVENT_WRQ: default: failf(conn->data, "%s\n", "Internal error: Unexpected packet"); break; } /* Update the progress meter */ if(Curl_pgrsUpdate(conn)) return CURLE_ABORTED_BY_CALLBACK; } } /* Check for transfer timeout every 10 blocks, or after timeout */ if(check_time%10==0) { time_t current; time(¤t); if(current>state->max_time) { DEBUGF(infof(data, "timeout: %d > %d\n", current, state->max_time)); state->error = TFTP_ERR_TIMEOUT; state->state = TFTP_STATE_FIN; } } } if(code) return code; /* Tell curl we're done */ code = Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL); if(code) return code; /* If we have encountered an error */ if(state->error) { /* Translate internal error codes to curl error codes */ switch(state->error) { case TFTP_ERR_NOTFOUND: code = CURLE_TFTP_NOTFOUND; break; case TFTP_ERR_PERM: code = CURLE_TFTP_PERM; break; case TFTP_ERR_DISKFULL: code = CURLE_TFTP_DISKFULL; break; case TFTP_ERR_ILLEGAL: code = CURLE_TFTP_ILLEGAL; break; case TFTP_ERR_UNKNOWNID: code = CURLE_TFTP_UNKNOWNID; break; case TFTP_ERR_EXISTS: code = CURLE_TFTP_EXISTS; break; case TFTP_ERR_NOSUCHUSER: code = CURLE_TFTP_NOSUCHUSER; break; case TFTP_ERR_TIMEOUT: code = CURLE_OPERATION_TIMEOUTED; break; case TFTP_ERR_NORESPONSE: code = CURLE_COULDNT_CONNECT; break; default: code= CURLE_ABORTED_BY_CALLBACK; break; } } else code = CURLE_OK; return code; } #endif