Fate #303031: Circumvent TFTP size restrictions in atftpd
The size of a single image file that can be transferred with TFTP is limited to
2^(2*8) *BLOCKSIZE (as per RFC 1350 there are only two bytes for the block
counter). This is problematic for one of our customers who needs to transfer
100+ MB Windows images using a TFTP client (NT bootloader) which has a
hardwared BLOCKSIZE setting of 1432).
block rollover
http://www.compuphase.com/tftp.htm
Patch originally from OpenSUSE:
https://build.opensuse.org/package/view_file/openSUSE:Leap:42.2/atftp/atftpd-0.7_circumvent_tftp_size_restrictions.patch?expand=1
Modified to apply for atftp-0.7.1 used in PhotonOS
diff --git a/tftp_def.h b/tftp_def.h.new
index e4b338d..6849d6f 100644
--- a/tftp_def.h
+++ b/tftp_def.h.new
@@ -32,6 +32,7 @@
#define TIMEOUT 5 /* Client timeout */
#define S_TIMEOUT 5 /* Server timout. */
#define NB_OF_RETRY 5
+#define MAXBLOCKS 1000000 /* maximum number of blocks in a download */
/* definition to use tftp_options structure */
#define OPT_FILENAME 0
diff --git a/tftp_file.c b/tftp_file.c.new
index 27ae4d0..baab66c 100644
--- a/tftp_file.c
+++ b/tftp_file.c.new
@@ -622,8 +622,8 @@ int tftp_send_file(struct client_data *data)
int state = S_SEND_REQ; /* current state in the state machine */
int timeout_state = state; /* what state should we go on when timeout */
int result;
- int block_number = 0;
- int last_block = -1;
+ long block_number = 0;
+ long last_block = -1;
int data_size; /* size of data received */
int sockfd = data->sockfd; /* just to simplify calls */
struct sockaddr_storage sa; /* a copy of data.sa_peer */
@@ -637,8 +637,8 @@ int tftp_send_file(struct client_data *data)
int convert = 0; /* if true, do netascii convertion */
char string[MAXLEN];
- int prev_block_number = 0; /* needed to support netascii convertion */
- int prev_file_pos = 0;
+ long prev_block_number = 0; /* needed to support netascii convertion */
+ long prev_file_pos = 0;
int temp = 0;
data->file_size = 0;
@@ -745,7 +745,7 @@ int tftp_send_file(struct client_data *data)
data_size, data->data_buffer);
data->file_size += data_size;
if (data->trace)
- fprintf(stderr, "sent DATA <block: %d, size: %d>\n",
+ fprintf(stderr, "sent DATA <block: %ld, size: %d>\n",
block_number + 1, data_size - 4);
state = S_WAIT_PACKET;
break;
@@ -785,7 +785,7 @@ int tftp_send_file(struct client_data *data)
}
block_number = ntohs(tftphdr->th_block);
if (data->trace)
- fprintf(stderr, "received ACK <block: %d>\n",
+ fprintf(stderr, "received ACK <block: %ld>\n",
block_number);
if ((last_block != -1) && (block_number > last_block))
{
diff --git a/tftp_io.c b/tftp_io.c.new
index 605a9c2..b559d5a 100644
--- a/tftp_io.c
+++ b/tftp_io.c.new
@@ -350,8 +350,8 @@ int tftp_get_packet(int sock1, int sock2, int *sock, struct sockaddr_storage *sa
/*
* Read from file and do netascii conversion if needed
*/
-int tftp_file_read(FILE *fp, char *data_buffer, int data_buffer_size, int block_number,
- int convert, int *prev_block_number, int *prev_file_pos, int *temp)
+int tftp_file_read(FILE *fp, char *data_buffer, int data_buffer_size, long block_number,
+ int convert, long *prev_block_number, long *prev_file_pos, int *temp)
{
int i;
int c;
diff --git a/tftp_io.h b/tftp_io.h.new
index da8c369..7840744 100644
--- a/tftp_io.h
+++ b/tftp_io.h.new
@@ -52,8 +52,8 @@ int tftp_send_data(int socket, struct sockaddr_storage *s_inn, short block_numbe
int tftp_get_packet(int sock1, int sock2, int *sock, struct sockaddr_storage *sa,
struct sockaddr_storage *from, struct sockaddr_storage *to,
int timeout, int *size, char *data);
-int tftp_file_read(FILE *fp, char *buffer, int buffer_size, int block_number, int convert,
- int *prev_block_number, int *prev_file_pos, int *temp);
+int tftp_file_read(FILE *fp, char *buffer, int buffer_size, long block_number, int convert,
+ long *prev_block_number, long *prev_file_pos, int *temp);
int tftp_file_write(FILE *fp, char *data_buffer, int data_buffer_size, int block_number,
int data_size, int convert, int *prev_block_number, int *temp);
#endif
diff --git a/tftpd_file.c b/tftpd_file.c.new
index da1d6c9..3b37f94 100644
--- a/tftpd_file.c
+++ b/tftpd_file.c.new
@@ -407,8 +407,9 @@ int tftpd_send_file(struct thread_data *data)
int state = S_BEGIN;
int timeout_state = state;
int result;
- int block_number = 0;
- int last_block = -1;
+ long block_number = 0;
+ long last_block = -1;
+ int block_loops = 0;
int data_size;
struct sockaddr_storage *sa = &data->client_info->client;
struct sockaddr_storage from;
@@ -431,8 +432,8 @@ int tftpd_send_file(struct thread_data *data)
struct client_info *client_old = NULL;
struct tftp_opt options[OPT_NUMBER];
- int prev_block_number = 0; /* needed to support netascii convertion */
- int prev_file_pos = 0;
+ long prev_block_number = 0; /* needed to support netascii convertion */
+ long prev_file_pos = 0;
int temp = 0;
/* look for mode option */
@@ -565,11 +566,12 @@ int tftpd_send_file(struct thread_data *data)
logger(LOG_INFO, "blksize option -> %d", result);
}
- /* Verify that the file can be sent in 2^16 block of BLKSIZE octets */
- if ((file_stat.st_size / (data->data_buffer_size - 4)) > 65535)
+ /* 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 to big, increase BLKSIZE");
+ logger(LOG_NOTICE, "Requested file too big, increase BLKSIZE");
+ logger(LOG_NOTICE, "Only %d blocks of %d bytes can be served.", MAXBLOCKS, data->data_buffer_size);
if (data->trace)
logger(LOG_DEBUG, "sent ERROR <code: %d, msg: %s>", EUNDEF,
tftp_errmsg[EUNDEF]);
@@ -880,10 +882,15 @@ int tftpd_send_file(struct thread_data *data)
}
/* The ACK is from the current client */
number_of_timeout = 0;
- block_number = ntohs(tftphdr->th_block);
+ block_number = (block_loops * 65536) + ntohs(tftphdr->th_block);
if (data->trace)
- logger(LOG_DEBUG, "received ACK <block: %d>",
- block_number);
+ {
+ logger(LOG_DEBUG, "received ACK <block: %d>", block_number);
+ }
+ if (ntohs(tftphdr->th_block) == 65535)
+ {
+ block_loops++;
+ };
if ((last_block != -1) && (block_number > last_block))
{
state = S_END;