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tftpd_file.c
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tftpd_file.c
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/* hey emacs! -*- Mode: C; c-file-style: "k&r"; indent-tabs-mode: nil -*- */
/*
* tftpd_file.c
* state machine for file transfer on the server side
*
* $Id: tftpd_file.c,v 1.51 2004/02/18 02:21:47 jp Exp $
*
* Copyright (c) 2000 Jean-Pierre Lefebvre <[email protected]>
* and Remi Lefebvre <[email protected]>
*
* atftp is free software; you can redistribute them and/or modify them
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/stat.h>
#include "tftpd.h"
#include "tftp_io.h"
#include "tftp_def.h"
#include "logger.h"
#include "options.h"
#ifdef HAVE_PCRE
#include "tftpd_pcre.h"
#endif
#define S_BEGIN 0
#define S_SEND_REQ 1
#define S_SEND_ACK 2
#define S_SEND_OACK 3
#define S_SEND_DATA 4
#define S_WAIT_PACKET 5
#define S_REQ_RECEIVED 6
#define S_ACK_RECEIVED 7
#define S_OACK_RECEIVED 8
#define S_DATA_RECEIVED 9
#define S_ABORT 10
#define S_END 11
/* read only variables unless for the main thread, at initialisation */
extern char directory[MAXLEN];
/* read only except for the main thread */
extern int tftpd_cancel;
extern int tftpd_prevent_sas;
#ifdef HAVE_PCRE
extern tftpd_pcre_self_t *pcre_top;
#endif
/*
* Rules for filenames. This is common to both tftpd_recieve_file
* and tftpd_send_file It is placed here to make sure the rules are
* consistent and clearer.
*/
int tftpd_rules_check(char *filename)
{
char string[MAXLEN];
/* If the filename does not start with the directory, change it */
if (strncmp(directory, filename, strlen(directory)) != 0)
{
/* Append the prefix directory to the requested file. */
snprintf(string, sizeof(string), "%s%s",
directory, filename);
Strncpy(filename, string, MAXLEN);
}
/* If the filename contain /../ sequences, we forbid the access */
if (strstr(filename, "/../") != NULL)
{
/* Illegal access. */
logger(LOG_INFO, "File name with /../ are forbidden");
return ERR;
}
return OK;
}
/*
* Receive a file. It is implemented as a state machine using a while loop
* and a switch statement. Function flow is as follow:
* - sanity check
* - check client's request
* - enter state machine
*
* 1) send a ACK or OACK
* 2) wait replay
* - if DATA packet, read it, send an acknowledge, goto 2
* - if ERROR abort
* - if TIMEOUT goto previous state
*/
int tftpd_receive_file(struct thread_data *data)
{
int state = S_BEGIN;
int timeout_state = state;
int windowblock = 0; /* number of block in a window, c.f. RFC7440 */
int windowsize = 1; /* c.f. RFC7440 */
int result;
long block_number = 0;
long last_received_block = 0;
int extra_ack = 0; /* number of additional ACKs */
int data_size;
int sockfd = data->sockfd;
struct sockaddr_storage *sa = &data->client_info->client;
struct sockaddr_storage from;
char addr_str[SOCKADDR_PRINT_ADDR_LEN];
struct tftphdr *tftphdr = (struct tftphdr *)data->data_buffer;
FILE *fp = NULL;
char filename[MAXLEN];
char string[MAXLEN];
int timeout = data->timeout;
int number_of_timeout = 0;
int all_blocks_received = 0; /* temporary kludge */
int convert = 0; /* if true, do netascii conversion */
long prev_block_number = 0; /* needed to support netascii conversion */
int temp = 0;
/* look for mode option */
if (strcasecmp(data->tftp_options[OPT_MODE].value, "netascii") == 0)
{
convert = 1;
logger(LOG_DEBUG, "will do netascii conversion");
}
/* file name verification */
Strncpy(filename, data->tftp_options[OPT_FILENAME].value,
MAXLEN);
if (tftpd_rules_check(filename) != OK)
{
tftp_send_error(sockfd, sa, EACCESS, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EACCESS,
tftp_errmsg[EACCESS]);
return ERR;
}
/* tsize option */
if (((result = opt_get_tsize(data->tftp_options)) > -1) && !convert)
{
opt_set_tsize(result, data->tftp_options);
logger(LOG_DEBUG, "tsize option -> %d", result);
}
/* windowsize */
if ((result = opt_get_windowsize(data->tftp_options)) > -1)
{
windowsize = result;
opt_set_windowsize(result, data->tftp_options);
logger(LOG_DEBUG, "windowsize option -> %d", result);
}
/* timeout option */
if ((result = opt_get_timeout(data->tftp_options)) > -1)
{
if ((result < 1) || (result > 255))
{
tftp_send_error(sockfd, sa, EOPTNEG, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EOPTNEG,
tftp_errmsg[EOPTNEG]);
return ERR;
}
timeout = result;
opt_set_timeout(timeout, data->tftp_options);
logger(LOG_DEBUG, "timeout option -> %d", timeout);
}
/* blksize */
if ((result = opt_get_blksize(data->tftp_options)) > -1)
{
/*
* If we receive more options, we have to make sure our buffer for
* the OACK is not too small. Use the string representation of
* the options here for simplicity, which puts us on the safe side.
* FIXME: Use independent buffers for OACK and data.
*/
opt_options_to_string(data->tftp_options, string, MAXLEN);
if ((result < strlen(string)-2) || (result > 65464))
{
logger(LOG_NOTICE, "options <%s> require roughly a blksize of %d for the OACK.",
string, strlen(string)-2);
tftp_send_error(sockfd, sa, EOPTNEG, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EOPTNEG,
tftp_errmsg[EOPTNEG]);
return ERR;
}
data->data_buffer_size = result + 4;
data->data_buffer = realloc(data->data_buffer, data->data_buffer_size);
if (data->data_buffer == NULL)
{
logger(LOG_ERR, "memory allocation failure");
return ERR;
}
tftphdr = (struct tftphdr *)data->data_buffer;
if (data->data_buffer == NULL)
{
tftp_send_error(sockfd, sa, ENOSPACE, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", ENOSPACE,
tftp_errmsg[ENOSPACE]);
return ERR;
}
opt_set_blksize(result, data->tftp_options);
logger(LOG_DEBUG, "blksize option -> %d", result);
}
/* that's it, we start receiving the file */
while (1)
{
if (tftpd_cancel)
{
logger(LOG_DEBUG, "thread cancelled");
tftp_send_error(sockfd, sa, EUNDEF, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EUNDEF,
tftp_errmsg[EUNDEF]);
state = S_ABORT;
}
switch (state)
{
case S_BEGIN:
/* Did the client request RFC1350 options ?*/
if (opt_support_options(data->tftp_options))
state = S_SEND_OACK;
else
state = S_SEND_ACK;
break;
case S_SEND_ACK:
windowblock = 0;
timeout_state = state;
tftp_send_ack(sockfd, sa, last_received_block);
if (data->trace)
logger(LOG_DEBUG, "sent ACK <block: %ld>", last_received_block);
if (all_blocks_received)
state = S_END;
else
state = S_WAIT_PACKET;
break;
case S_SEND_OACK:
windowblock = 0;
timeout_state = state;
tftp_send_oack(sockfd, sa, data->tftp_options,
data->data_buffer, data->data_buffer_size);
if (data->trace) {
opt_options_to_string(data->tftp_options, string, MAXLEN);
logger(LOG_DEBUG, "sent OACK <%s>", string);
}
state = S_WAIT_PACKET;
break;
case S_WAIT_PACKET:
data_size = data->data_buffer_size;
result = tftp_get_packet(sockfd, -1, NULL, sa, &from, NULL,
timeout, 0, &data_size, data->data_buffer);
switch (result)
{
case GET_TIMEOUT:
number_of_timeout++;
if (number_of_timeout > NB_OF_RETRY)
{
logger(LOG_INFO, "client (%s) not responding",
sockaddr_print_addr(&data->client_info->client,
addr_str, sizeof(addr_str)));
state = S_END;
}
else
{
logger(LOG_WARNING, "timeout: retrying ...");
state = timeout_state;
}
break;
case GET_ERROR:
/*
* This does not work correctly if load balancers are
* employed on one side of a multihomed host. ie, the
* tftp RRQ goes through the load balancer and has the
* source ports changed while the multicast traffic
* bypasses the load balancers.
*
* **** It is not compliant with RFC1350 to skip this
* **** test since the port number is the TID. Use this
* **** only if you know what you're doing.
*/
if (sockaddr_get_port(sa) != sockaddr_get_port(&from))
{
if (data->checkport)
{
logger(LOG_WARNING, "packet discarded <%s>",
sockaddr_print_addr(&from, addr_str,
sizeof(addr_str)));
break;
}
else
logger(LOG_WARNING, "source port mismatch, check bypassed");
}
Strncpy(string, tftphdr->th_msg, sizeof(string));
if (data->trace)
logger(LOG_DEBUG, "received ERROR <code: %d, msg: %s>",
ntohs(tftphdr->th_code), string);
state = S_ABORT;
break;
case GET_DATA:
/* Check that source port match */
if (sockaddr_get_port(sa) != sockaddr_get_port(&from))
{
if (data->checkport)
{
logger(LOG_WARNING, "packet discarded <%s>",
sockaddr_print_addr(&from, addr_str,
sizeof(addr_str)));
break;
}
else
logger(LOG_WARNING, "source port mismatch, check bypassed");
}
number_of_timeout = 0;
state = S_DATA_RECEIVED;
break;
case GET_DISCARD:
/* FIXME: should we increment number_of_timeout */
logger(LOG_WARNING, "packet discarded <%s>",
sockaddr_print_addr(&from, addr_str,
sizeof(addr_str)));
break;
case ERR:
logger(LOG_ERR, "%s: %d: recvfrom: %s",
__FILE__, __LINE__, strerror(errno));
state = S_ABORT;
break;
default:
logger(LOG_ERR, "%s: %d: abnormal return value %d",
__FILE__, __LINE__, result);
state = S_ABORT;
}
break;
case S_DATA_RECEIVED:
if (fp == NULL) {
/* Open the file for writing. */
if ((fp = fopen(filename, "w")) == NULL)
{
/* Can't create the file. */
logger(LOG_INFO, "Can't open %s for writing", filename);
tftp_send_error(sockfd, sa, EACCESS, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EACCESS,
tftp_errmsg[EACCESS]);
return ERR;
}
}
/* We need to seek to the right place in the file */
block_number = tftp_rollover_blocknumber(ntohs(tftphdr->th_block), prev_block_number, 0);
/* The first data package acknowledges the OACK */
if ((last_received_block < windowsize) && (timeout_state = S_SEND_OACK))
timeout_state = S_SEND_ACK;
/* The sequence of blocks may contain a gap, i.e. (block_number > last_received_block + 1).
Send an extra ACK for the last block before the gap once.
The ACK of a received window gets lost. The sender times out and starts
sending all blocks of that window again, i.e. (block_number < last_received_block + 1).
Again, send the extra ACK. */
if (block_number != last_received_block + 1) {
/* We got a wrong block from the client, send ACK for last block again */
if (extra_ack < 1) {
logger(LOG_DEBUG, "got wrong block <block: %ld>, sending extra ACK for <block: %ld>",
block_number, last_received_block);
extra_ack++;
state = S_SEND_ACK;
} else {
logger(LOG_DEBUG, "got wrong block <block: %ld>, ignoring", block_number);
state = S_WAIT_PACKET;
}
break;
}
extra_ack = 0;
windowblock++;
if (data->trace)
logger(LOG_DEBUG, "received %d. DATA <block: %ld, size %d>, update last received block: %ld → %ld>",
windowblock, block_number, data_size - 4, last_received_block, block_number);
last_received_block = block_number;
if (tftp_file_write(fp, tftphdr->th_data, data->data_buffer_size - 4, block_number,
data_size - 4, convert, &prev_block_number, &temp) != data_size - 4)
{
logger(LOG_ERR, "%s: %d: error writing to file %s",
__FILE__, __LINE__, filename);
tftp_send_error(sockfd, sa, ENOSPACE, data->data_buffer,
data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>",
ENOSPACE, tftp_errmsg[ENOSPACE]);
state = S_ABORT;
break;
}
if (data_size < data->data_buffer_size)
all_blocks_received = 1;
else
all_blocks_received = 0;
if ((windowblock >= windowsize) || (all_blocks_received))
state = S_SEND_ACK;
else
state = S_WAIT_PACKET;
break;
case S_END:
if (fp != NULL) fclose(fp);
logger(LOG_DEBUG, "End of transfer");
return OK;
case S_ABORT:
if (fp != NULL) fclose(fp);
logger(LOG_DEBUG, "Aborting transfer");
return ERR;
default:
if (fp != NULL) fclose(fp);
logger(LOG_ERR, "%s: %d: tftpd_file.c: huh?",
__FILE__, __LINE__);
return ERR;
}
}
}
/*
* Send a file. It is implemented as a state machine using a while loop
* and a switch statement. Function flow is as follow:
* - sanity check
* - check client's request
* - enter state machine
*
* 1) send a DATA or OACK
* 2) wait replay
* - if ACK, goto 3
* - if ERROR abort
* - if TIMEOUT goto previous state
* 3) send data, goto 2
*/
int tftpd_send_file(struct thread_data *data)
{
int state = S_BEGIN;
int timeout_state = state;
int result;
long block_number = 0;
long last_ackd_block = -1;
long last_block = -1;
int data_size;
struct sockaddr_storage *sa = &data->client_info->client;
struct sockaddr_storage from;
char addr_str[SOCKADDR_PRINT_ADDR_LEN];
int sockfd = data->sockfd;
struct tftphdr *tftphdr = (struct tftphdr *)data->data_buffer;
FILE *fp;
char filename[MAXLEN];
char string[MAXLEN];
int timeout = data->timeout;
int windowblock = 0;
int windowsize = 1;
int in_window_ack = -1;
int delay = 0; /* delay between datagrams in a window */
int number_of_timeout = 0;
int mcast_switch = data->mcast_switch_client;
struct stat file_stat;
int convert = 0; /* if true, do netascii conversion */
struct thread_data *thread = NULL; /* used when looking for a multicast
thread */
int multicast = 0; /* set to 1 if multicast */
struct client_info *client_info = data->client_info;
struct client_info *client_old = NULL;
struct tftp_opt options[OPT_NUMBER];
long prev_block_number = 0; /* needed to support netascii conversion */
long prev_file_pos = 0;
int temp = 0;
int prev_sent_count = 0;
int prev_ack_count = 0;
int curr_sent_count = 0;
/* look for mode option */
if (strcasecmp(data->tftp_options[OPT_MODE].value, "netascii") == 0)
{
convert = 1;
logger(LOG_DEBUG, "will do netascii conversion");
}
/* file name verification */
Strncpy(filename, data->tftp_options[OPT_FILENAME].value,
MAXLEN);
if (tftpd_rules_check(filename) != OK)
{
tftp_send_error(sockfd, sa, EACCESS, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EACCESS,
tftp_errmsg[EACCESS]);
return ERR;
}
/* verify that the requested file exist */
fp = fopen(filename, "r");
#ifdef HAVE_PCRE
if (fp == NULL)
{
/* Verify if this file have a working subsitution */
if (pcre_top != NULL)
{
if (tftpd_pcre_sub(pcre_top, string, MAXLEN,
data->tftp_options[OPT_FILENAME].value) < 0)
{
logger(LOG_DEBUG, "PCRE failed to match");
}
else
{
logger(LOG_INFO, "PCRE mapped %s -> %s",
data->tftp_options[OPT_FILENAME].value, string);
Strncpy(filename, string, MAXLEN);
/* recheck those rules */
if (tftpd_rules_check(filename) != OK)
{
tftp_send_error(sockfd, sa, EACCESS, data->data_buffer,
data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EACCESS,
tftp_errmsg[EACCESS]);
return ERR;
}
/* write back the new file name to the option structure */
opt_set_options(data->tftp_options, "filename", filename);
/* try to open this new file */
fp = fopen(filename, "r");
}
}
}
#endif
if (fp == NULL)
{
tftp_send_error(sockfd, sa, ENOTFOUND, data->data_buffer, data->data_buffer_size);
logger(LOG_INFO, "File %s not found", filename);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", ENOTFOUND,
tftp_errmsg[ENOTFOUND]);
return ERR;
}
/* To return the size of the file with tsize argument */
fstat(fileno(fp), &file_stat);
/* tsize option */
if ((opt_get_tsize(data->tftp_options) > -1) && !convert)
{
opt_set_tsize(file_stat.st_size, data->tftp_options);
logger(LOG_INFO, "tsize option -> %d", file_stat.st_size);
}
/* timeout option */
if ((result = opt_get_timeout(data->tftp_options)) > -1)
{
if ((result < 1) || (result > 255))
{
tftp_send_error(sockfd, sa, EOPTNEG, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EOPTNEG,
tftp_errmsg[EOPTNEG]);
fclose(fp);
return ERR;
}
timeout = result;
opt_set_timeout(timeout, data->tftp_options);
logger(LOG_INFO, "timeout option -> %d", timeout);
}
/* windowsize option */
if ((result = opt_get_windowsize(data->tftp_options)) > -1)
{
if ((result < 1) || (result > 65535))
{
tftp_send_error(sockfd, sa, EOPTNEG, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EOPTNEG,
tftp_errmsg[EOPTNEG]);
fclose(fp);
return ERR;
}
windowsize = result;
opt_set_windowsize(windowsize, data->tftp_options);
logger(LOG_INFO, "windowsize option -> %d", windowsize);
}
/* blksize */
if ((result = opt_get_blksize(data->tftp_options)) > -1)
{
/*
* If we receive more options, we have to make sure our buffer for
* the OACK is not too small. Use the string representation of
* the options here for simplicity, which puts us on the safe side.
* FIXME: Use independent buffers for OACK and data.
*/
opt_options_to_string(data->tftp_options, string, MAXLEN);
if ((result < strlen(string)-2) || (result > 65464))
{
logger(LOG_NOTICE, "options <%s> require roughly a blksize of %d for the OACK.",
string, strlen(string)-2);
tftp_send_error(sockfd, sa, EOPTNEG, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EOPTNEG,
tftp_errmsg[EOPTNEG]);
fclose(fp);
return ERR;
}
data->data_buffer_size = result + 4;
data->data_buffer = realloc(data->data_buffer, data->data_buffer_size);
if (data->data_buffer == NULL)
{
logger(LOG_ERR, "memory allocation failure");
fclose(fp);
return ERR;
}
tftphdr = (struct tftphdr *)data->data_buffer;
if (data->data_buffer == NULL)
{
tftp_send_error(sockfd, sa, ENOSPACE, data->data_buffer, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", ENOSPACE,
tftp_errmsg[ENOSPACE]);
fclose(fp);
return ERR;
}
opt_set_blksize(result, data->tftp_options);
logger(LOG_INFO, "blksize option -> %d", result);
}
/* Verify that the file can be sent in MAXBLOCKS blocks of BLKSIZE octets */
if ((file_stat.st_size / (data->data_buffer_size - 4)) > MAXBLOCKS)
{
tftp_send_error(sockfd, sa, EUNDEF, data->data_buffer, data->data_buffer_size);
logger(LOG_NOTICE, "Requested file too big, increase BLKSIZE");
logger(LOG_NOTICE, "Only %d blocks of %d bytes can be served via multicast", MAXBLOCKS, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EUNDEF,
tftp_errmsg[EUNDEF]);
fclose(fp);
return ERR;
}
/* multicast option */
if (data->tftp_options[OPT_MULTICAST].specified &&
data->tftp_options[OPT_MULTICAST].enabled && !convert)
{
/* Verify that the file can be sent in 65536 blocks of BLKSIZE octets */
if ((file_stat.st_size / (data->data_buffer_size - 4)) > 65536)
{
tftp_send_error(sockfd, sa, EUNDEF, data->data_buffer, data->data_buffer_size);
logger(LOG_NOTICE, "Requested file too big, increase BLKSIZE");
logger(LOG_NOTICE, "Only %d blocks of %d bytes can be served.", 65536, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EUNDEF,
tftp_errmsg[EUNDEF]);
fclose(fp);
return ERR;
}
/*
* Find a server with the same options to give up the client.
*/
logger(LOG_DEBUG, "Searching a server thread to give up this client");
result = tftpd_list_find_multicast_server_and_add(&thread, data, data->client_info);
if ( result > 0)
{
/* add this client to its list of client */
if (result == 1)
logger(LOG_DEBUG, "Added client %p to thread %p", data->client_info,
thread);
else
logger(LOG_DEBUG, "Client (%p) is already in list of thread %p",
data->client_info, thread);
/* NULL our own pointer so we don't free memory */
if (result == 1)
data->client_info = NULL;
/* Look at needed information to oack that client */
opt_set_multicast(data->tftp_options, thread->mc_addr,
thread->mc_port, 0);
logger(LOG_INFO, "multicast option -> %s,%d,%d",
thread->mc_addr, thread->mc_port, 0);
/* Send an OACK to that client. There is a possible race condition
here where the new server thread OACK this client before us. This should
not be a problem: the client thread will receive a second OACK and fall
back to non master mode. Then the server will timeout and either resend
OACK or continu with the next client */
if (data->trace)
{
opt_options_to_string(data->tftp_options, string, MAXLEN);
logger(LOG_DEBUG, "sent OACK <%s>", string);
}
tftp_send_oack(thread->sockfd, sa, data->tftp_options,
data->data_buffer, data->data_buffer_size);
/* We are done */
logger(LOG_INFO, "Client transferred to %p", thread);
fclose(fp);
return OK;
}
else
{
struct addrinfo hints, *result;
/* configure socket, get an IP address */
if (tftpd_mcast_get_tid(&data->mc_addr, &data->mc_port) != OK)
{
logger(LOG_ERR, "No multicast address/port available");
fclose(fp);
return ERR;
}
logger(LOG_DEBUG, "mcast_addr: %s, mcast_port: %d",
data->mc_addr, data->mc_port);
/* convert address */
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_DGRAM;
hints.ai_flags = AI_NUMERICHOST;
if (getaddrinfo(data->mc_addr, NULL, &hints, &result) ||
sockaddr_set_addrinfo(&data->sa_mcast, result))
{
logger(LOG_ERR, "bad address %s\n",data->mc_addr);
fclose(fp);
return ERR;
}
freeaddrinfo(result);
sockaddr_set_port(&data->sa_mcast, data->mc_port);
/* verify address is multicast */
if (!sockaddr_is_multicast(&data->sa_mcast))
{
logger(LOG_ERR, "bad multicast address %s\n",
sockaddr_print_addr(&data->sa_mcast,
addr_str, sizeof(addr_str)));
fclose(fp);
return ERR;
}
/* initialise multicast address structure */
sockaddr_get_mreq(&data->sa_mcast, &data->mcastaddr);
if (data->sa_mcast.ss_family == AF_INET)
setsockopt(data->sockfd, IPPROTO_IP, IP_MULTICAST_TTL,
&data->mcast_ttl, sizeof(data->mcast_ttl));
else
setsockopt(data->sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
&data->mcast_ttl, sizeof(data->mcast_ttl));
/* set options data for OACK */
opt_set_multicast(data->tftp_options, data->mc_addr,
data->mc_port, 1);
logger(LOG_INFO, "multicast option -> %s,%d,%d", data->mc_addr,
data->mc_port, 1);
/* the socket must be unconnected for multicast */
sa->ss_family = AF_UNSPEC;
connect(sockfd, (struct sockaddr *)sa, sizeof(*sa));
/* set multicast flag */
multicast = 1;
/* Now ready to receive new clients */
tftpd_clientlist_ready(data);
}
}
/* copy options to local structure, used when falling back a client to slave */
memcpy(options, data->tftp_options, sizeof(options));
opt_set_multicast(options, data->mc_addr, data->mc_port, 0);
/* That's it, ready to send the file */
while (1)
{
if (tftpd_cancel)
{
/* Send error to all client */
logger(LOG_DEBUG, "thread cancelled");
do
{
tftpd_clientlist_done(data, client_info, NULL);
tftp_send_error(sockfd, &client_info->client,
EUNDEF, data->data_buffer, data->data_buffer_size);
if (data->trace)
{
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s> to %s", EUNDEF,
tftp_errmsg[EUNDEF],
sockaddr_print_addr(&client_info->client,
addr_str, sizeof(addr_str)));
}
} while (tftpd_clientlist_next(data, &client_info) == 1);
state = S_ABORT;
}
switch (state)
{
case S_BEGIN:
if (opt_support_options(data->tftp_options))
state = S_SEND_OACK;
else
state = S_SEND_DATA;
break;
case S_SEND_OACK:
timeout_state = state;
if (data->trace) {
opt_options_to_string(data->tftp_options, string, MAXLEN);
logger(LOG_DEBUG, "sent OACK <%s>", string);
}
tftp_send_oack(sockfd, sa, data->tftp_options,
data->data_buffer, data->data_buffer_size);
state = S_WAIT_PACKET;
break;
case S_SEND_DATA:
windowblock++;
timeout_state = state;
data_size = tftp_file_read(fp, tftphdr->th_data, data->data_buffer_size - 4, block_number,
convert, &prev_block_number, &prev_file_pos, &temp);
data_size += 4; /* need to consider tftp header */
/* record the last block number */
if (feof(fp))
last_block = block_number;
if (multicast)
{
tftp_send_data(sockfd, &data->sa_mcast,
block_number + 1, data_size,
data->data_buffer);
}
else
{
tftp_send_data(sockfd, sa, block_number + 1,
data_size, data->data_buffer);
}
if (data->trace)
logger(LOG_DEBUG, "sent %d. DATA <block: %ld, size %d>",
windowblock, block_number + 1, data_size - 4);
state = S_WAIT_PACKET;
break;
case S_WAIT_PACKET:
data_size = data->data_buffer_size;
if ((windowblock >= windowsize) || (last_ackd_block == -1) || (last_block != -1)) {
/* we wait for the ACK */
result = tftp_get_packet(sockfd, -1, NULL, sa, &from, NULL,
timeout, 0, &data_size, data->data_buffer);
if ((delay > 0) && (in_window_ack == 0))
delay--;
in_window_ack = 0;
} else {
/* we check if an unsolicitated ACK arrived */
result = tftp_get_packet(sockfd, -1, NULL, sa, &from, NULL,
0, delay, &data_size, data->data_buffer);
if (result == GET_TIMEOUT) {
/* we send the next block */
block_number = tftp_rollover_blocknumber(
ntohs(tftphdr->th_block), prev_block_number, 0);
state = S_SEND_DATA;
break;
}
in_window_ack++;
}
switch (result)
{
case GET_TIMEOUT:
number_of_timeout++;
windowblock = 0;
if (number_of_timeout > NB_OF_RETRY)
{
logger(LOG_INFO, "client (%s) not responding",
sockaddr_print_addr(&client_info->client,
addr_str, sizeof(addr_str)));
state = S_END;
}
else
{
/* The client failed to ACK our last packet. Send an
OACK with mc=0 to it, fetch the next client in the
list and continu with this new one */
if (multicast && mcast_switch)
{
client_old = client_info;
tftpd_clientlist_next(data, &client_info);
if (client_info && (client_info != client_old))
{
/* Send an OACK to the old client remove is
master client status */
if (data->trace)
{
opt_options_to_string(options, string, MAXLEN);
logger(LOG_DEBUG, "sent OACK <%s>", string);
}
tftp_send_oack(sockfd, sa, options,
data->data_buffer, data->data_buffer_size);
/* Proceed normally with the next client,
going to OACK state */
logger(LOG_INFO,
"Serving next client: %s:%d",
sockaddr_print_addr(
&client_info->client,
addr_str, sizeof(addr_str)),
sockaddr_get_port(
&client_info->client));
sa = &client_info->client;
/* rewind the last_ackd_block counter */
last_ackd_block = -1;
state = S_SEND_OACK;
break;
}
else if (client_info == NULL)
{
/* we got a big problem if this happend */
logger(LOG_ERR,
"%s: %d: abnormal condition",
__FILE__, __LINE__);
state = S_ABORT;
break;
}
}
logger(LOG_WARNING, "timeout block %ld: retrying ...", block_number);
/* rewind the block_number to the last block we received */
block_number = last_ackd_block;
state = timeout_state;
}
break;
case GET_ACK:
/* handle case where packet come from un unexpected client */
if (multicast)
{
if (!sockaddr_equal(sa, &from))
{
/* We got an ACK from a client that is not the master client.
* If this is an ACK for the last block, mark this client as
* done
*/
if ((last_block != -1) && (block_number > last_block))
{
if (tftpd_clientlist_done(data, NULL, &from) == 1)
logger(LOG_DEBUG, "client done <%s>",
sockaddr_print_addr(
&from, addr_str,
sizeof(addr_str)));
else
logger(LOG_WARNING, "packet discarded <%s:%d>",
sockaddr_print_addr(
&from, addr_str,
sizeof(addr_str)),
sockaddr_get_port(&from));
}
else
/* If not, send and OACK with mc=0 to shut it up. */
{
if (data->trace)
{
opt_options_to_string(options, string, MAXLEN);
logger(LOG_DEBUG, "sent OACK <%s>", string);
}
tftp_send_oack(sockfd, &from, options,
data->data_buffer, data->data_buffer_size);
}
break;
}
}
else
{
/* check that the packet is from the current client */
if (sockaddr_get_port(sa) != sockaddr_get_port(&from))
{
if (data->checkport)
{
logger(LOG_WARNING, "packet discarded <%s:%d>",
sockaddr_print_addr(&from, addr_str,