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Handle the case where no IDB follows the SHB. This fixes part of 

https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=7533
which deals with Div by 0 crash in pcapng_read_packet_block().

svn path=/trunk/; revision=44074
This commit is contained in:
Michael Tüxen 2012-07-27 18:43:53 +00:00
parent 26d1cbb989
commit d8c4c4617c
1 changed files with 30 additions and 34 deletions
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64
wiretap/pcapng.c
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@ -2056,6 +2056,35 @@ pcapng_open(wtap *wth, int *err, gchar **err_info)
/* Loop over all IDB:s that appear before any packets */
while (1) {
/* peek at next block */
/* Try to read the (next) block header */
saved_offset = file_tell(wth->fh);
errno = WTAP_ERR_CANT_READ;
bytes_read = file_read(&bh, sizeof bh, wth->fh);
if (bytes_read == 0) {
pcapng_debug0("No more IDBs available...");
break;
}
if (bytes_read != sizeof bh) {
*err = file_error(wth->fh, err_info);
pcapng_debug3("pcapng_open: Check for more IDB:s, file_read() returned %d instead of %u, err = %d.", bytes_read, (unsigned int)sizeof bh, *err);
if (*err == 0)
*err = WTAP_ERR_SHORT_READ;
return -1;
}
/* go back to where we were */
file_seek(wth->fh, saved_offset, SEEK_SET, err);
if (pn.byte_swapped) {
bh.block_type = BSWAP32(bh.block_type);
}
pcapng_debug1("pcapng_open: Check for more IDB:s block_type 0x%x", bh.block_type);
if (bh.block_type != BLOCK_TYPE_IDB) {
break; /* No more IDB:s */
}
bytes_read = pcapng_read_block(wth->fh, FALSE, &pn, &wblock, err, err_info);
if (bytes_read == 0) {
pcapng_debug0("No more IDBs available...");
@ -2068,7 +2097,6 @@ pcapng_open(wtap *wth, int *err, gchar **err_info)
*err = WTAP_ERR_SHORT_READ;
return -1;
}
int_data.wtap_encap = wblock.data.if_descr.wtap_encap;
int_data.time_units_per_second = wblock.data.if_descr.time_units_per_second;
int_data.link_type = wblock.data.if_descr.link_type;
@ -2102,42 +2130,10 @@ pcapng_open(wtap *wth, int *err, gchar **err_info)
g_array_append_val(pcapng->interface_data, interface_data);
pcapng->number_of_interfaces++;
pcapng->read_idbs = FALSE;
pcapng_debug2("pcapng_open: Read IDB number_of_interfaces %u, wtap_encap %i", wth->number_of_interfaces, int_data.wtap_encap);
/* peek at next block */
/* Try to read the (next) block header */
saved_offset = file_tell(wth->fh);
errno = WTAP_ERR_CANT_READ;
bytes_read = file_read(&bh, sizeof bh, wth->fh);
if (bytes_read == 0) {
pcapng_debug0("No more IDBs available...");
break;
}
if (bytes_read != sizeof bh) {
*err = file_error(wth->fh, err_info);
pcapng_debug3("pcapng_open: Check for more IDB:s, file_read() returned %d instead of %u, err = %d.", bytes_read, (unsigned int)sizeof bh, *err);
if (*err == 0)
*err = WTAP_ERR_SHORT_READ;
return -1;
}
/* go back to where we were */
file_seek(wth->fh, saved_offset, SEEK_SET, err);
if (pn.byte_swapped) {
bh.block_type = BSWAP32(bh.block_type);
}
pcapng_debug1("pcapng_open: Check for more IDB:s block_type 0x%x", bh.block_type);
if (bh.block_type != BLOCK_TYPE_IDB) {
break; /* No more IDB:s */
}
}
pcapng->read_idbs = FALSE;
return 1;
}