As defined in the C standard:
In all cases the argument is an int, the value of which shall
be representable as an unsigned char or shall equal the value
of the macro EOF. If the argument has any other value, the
behavior is undefined.
This is because they're designed to work with the int values returned
by getc or fgetc; they need extra work to handle a char value.
If EOF is -1 (as it almost always is), with 8-bit bytes, the allowed
inputs to the ctype(3) functions are:
{-1, 0, 1, 2, 3, ..., 255}.
However, on platforms where char is signed, such as x86 with the
usual ABI, code like
char *arg = ...;
... isspace(*arg) ...
may pass in values in the range:
{-128, -127, -126, ..., -2, -1, 0, 1, ..., 127}.
This has two problems:
1. Inputs in the set {-128, -127, -126, ..., -2} are forbidden.
2. The non-EOF byte 0xff is conflated with the value EOF = -1, so
even though the input is not forbidden, it may give the wrong
answer.
Casting char to int first before passing the result to ctype(3)
doesn't help: inputs like -128 are unchanged by this cast. It is
necessary to cast char inputs to unsigned char first; you can then
cast to int if you like but there's no need because the functions
will always convert the argument to int by definition. So the above
fragment needs to be:
char *arg = ...;
... isspace((unsigned char)*arg) ...
This patch inserts unsigned char casts where necessary, and changes
int casts to unsigned char casts where the input is char.
I left alone int casts where the input is unsigned char already --
they're not immediately harmful, although they would have the effect
of suppressing some compiler warnings if the input is ever changed to
be char instead of unsigned char, so it might be better to remove
those casts too.
I also left alone calls where the input is int to begin with because
it came from getc; casting to unsigned char here would be wrong, of
course.
When re-reading upstream servers from /etc/resolv.conf or other
sources that can change dnsmasq tries to avoid memory fragmentation by
re-using existing records that are being re-read unchanged. This
involves seaching all the server records for each new one installed.
During startup this search is pointless, and can cause long start
times with thousands of --server options because the work needed is
O(n^2). Handle this case more intelligently. Thanks to Ye Zhou for
spotting the problem and an initial patch.
The code added in6 c596f1cc1d92b2b90ef5ce043ace314eefa868b
fails to free the returned datastructures from gethostinfo()
because sdetails.hostinfo is used to loop through the addresses
and ends up NULL. In some libc implementations this results
in a SEGV when freeaddrinfo() is called.
Also fix FTBFS under BSD. Thanks to Johnny S. Lee for the bug report.
Also Dbus SetDomainServers method.
Revert getaddrinfo hints.ai_socktype to SOCK_DGRAM to eliminate
duplicating every address three times for DGRAM, STREAM and RAW
in the results.
This gives dnsmasq the ability to originate retries for upstream DNS
queries itself, rather than relying on the downstream client. This is
most useful when doing DNSSEC over unreliable upstream network. It
comes with some cost in memory usage and network bandwidth.
By default, when sending a query via random ports to multiple upstream servers or
retrying a query dnsmasq will use a single random port for all the tries/retries.
This option allows a larger number of ports to be used, which can increase robustness
in certain network configurations. Note that increasing this to more than
two or three can have security and resource implications and should only
be done with understanding of those.
This change also removes a previous bug
where --dhcp-alternate-port would affect the port used
to relay _to_ as well as the port being listened on.
The new feature allows configuration to provide bug-for-bug
compatibility, if required. Thanks to Damian Kaczkowski
for the feature suggestion.
This allows hosts get a domain which relects the interface they
are attached to in a way which doesn't require hard-coding addresses.
Thanks to Sten Spans for the idea.
Fix the following build failure with gcc 4.8 raised since version 2.86:
option.c: In function 'one_opt':
option.c:2445:11: error: 'for' loop initial declarations are only allowed in C99 mode
for (char *p = arg; *p; p++) {
^
option.c:2445:11: note: use option -std=c99 or -std=gnu99 to compile your code
option.c:2453:11: error: 'for' loop initial declarations are only allowed in C99 mode
for (u8 i = 0; i < sizeof(daemon->umbrella_device); i++, arg+=2) {
^
Fixes:
- http://autobuild.buildroot.org/results/39b34a4e69fc10f4bd9d4ddb0ed8c0aae5741c84
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
To be treated as hex, the pattern must consist of only hex digits AND
contain at least one ':'. Thanks to Bengt-Erik Sandstrom who tripped
over a pattern consisting of a decimal number which was interpreted
surprisingly.
Previously, the prefix was limited to [8,16,24,32] for IPv4 and
to multiples of 4 for IPv6. This patch also makes the prefix-length optional
for --rev-server.
Inspired by a patch from DL6ER <dl6er@dl6er.de>, but completely
re-written by srk. All bugs are his.
Error: STRING_OVERFLOW (CWE-120): [#def99]
dnsmasq-2.86test7/src/option.c:801: fixed_size_dest: You might overrun the 100-character fixed-size string "buff" by copying "usage[i].arg" without checking the length.
# 799| if (usage[i].arg)
# 800| {
# 801|-> strcpy(buff, usage[i].arg);
# 802| for (j = 0; tab[j].handle; j++)
# 803| if (tab[j].handle == *(usage[i].arg))
Error: CLANG_WARNING: [#def100]
dnsmasq-2.86test7/src/option.c:962:3: warning[deadcode.DeadStores]: Value stored to 'domain' is never read
# 960| }
# 961|
# 962|-> domain += sprintf(domain, "in-addr.arpa");
# 963|
# 964| return 1;
Error: CLANG_WARNING: [#def101]
dnsmasq-2.86test7/src/option.c:981:3: warning[deadcode.DeadStores]: Value stored to 'domain' is never read
# 979| domain += sprintf(domain, "%.1x.", (i>>2) & 1 ? dig & 15 : dig >> 4);
# 980| }
# 981|-> domain += sprintf(domain, "ip6.arpa");
# 982|
# 983| return 1;
Error: RESOURCE_LEAK (CWE-772): [#def102] [important]
dnsmasq-2.86test7/src/option.c:1809: alloc_fn: Storage is returned from allocation function "opt_malloc".
dnsmasq-2.86test7/src/option.c:1809: var_assign: Assigning: "path" = storage returned from "opt_malloc(strlen(directory) + len + 2UL)".
dnsmasq-2.86test7/src/option.c:1810: noescape: Resource "path" is not freed or pointed-to in "strcpy". [Note: The source code implementation of the function has been overridden by a builtin model.]
dnsmasq-2.86test7/src/option.c:1811: noescape: Resource "path" is not freed or pointed-to in "strcat". [Note: The source code implementation of the function has been overridden by a builtin model.]
dnsmasq-2.86test7/src/option.c:1812: noescape: Resource "path" is not freed or pointed-to in "strcat". [Note: The source code implementation of the function has been overridden by a builtin model.]
dnsmasq-2.86test7/src/option.c:1815: noescape: Resource "path" is not freed or pointed-to in "stat".
dnsmasq-2.86test7/src/option.c:1809: overwrite_var: Overwriting "path" in "path = opt_malloc(strlen(directory) + len + 2UL)" leaks the storage that "path" points to.
# 1807| continue;
# 1808|
# 1809|-> path = opt_malloc(strlen(directory) + len + 2);
# 1810| strcpy(path, directory);
# 1811| strcat(path, "/");
Error: RESOURCE_LEAK (CWE-772): [#def103] [important]
dnsmasq-2.86test7/src/option.c:1809: alloc_fn: Storage is returned from allocation function "opt_malloc".
dnsmasq-2.86test7/src/option.c:1809: var_assign: Assigning: "path" = storage returned from "opt_malloc(strlen(directory) + len + 2UL)".
dnsmasq-2.86test7/src/option.c:1810: noescape: Resource "path" is not freed or pointed-to in "strcpy". [Note: The source code implementation of the function has been overridden by a builtin model.]
dnsmasq-2.86test7/src/option.c:1811: noescape: Resource "path" is not freed or pointed-to in "strcat". [Note: The source code implementation of the function has been overridden by a builtin model.]
dnsmasq-2.86test7/src/option.c:1812: noescape: Resource "path" is not freed or pointed-to in "strcat". [Note: The source code implementation of the function has been overridden by a builtin model.]
dnsmasq-2.86test7/src/option.c:1815: noescape: Resource "path" is not freed or pointed-to in "stat".
dnsmasq-2.86test7/src/option.c:1858: leaked_storage: Variable "path" going out of scope leaks the storage it points to.
# 1856| free(files);
# 1857| }
# 1858|-> break;
# 1859| }
# 1860|
Error: RESOURCE_LEAK (CWE-772): [#def104] [important]
dnsmasq-2.86test7/src/option.c:1996: alloc_fn: Storage is returned from allocation function "canonicalise_opt".
dnsmasq-2.86test7/src/option.c:1996: var_assign: Assigning: "name" = storage returned from "canonicalise_opt(arg)".
dnsmasq-2.86test7/src/option.c:1998: leaked_storage: Variable "name" going out of scope leaks the storage it points to.
# 1996| if (!(name = canonicalise_opt(arg)) ||
# 1997| (comma && !(target = canonicalise_opt(comma))))
# 1998|-> ret_err(_("bad MX name"));
# 1999|
# 2000| new = opt_malloc(sizeof(struct mx_srv_record));
Error: RESOURCE_LEAK (CWE-772): [#def106] [important]
dnsmasq-2.86test7/src/option.c:3477: alloc_fn: Storage is returned from allocation function "opt_malloc".
dnsmasq-2.86test7/src/option.c:3477: var_assign: Assigning: "new" = storage returned from "opt_malloc(96UL)".
dnsmasq-2.86test7/src/option.c:3618: leaked_storage: Variable "new" going out of scope leaks the storage it points to.
# 3616| sprintf(errstr, _("duplicate dhcp-host IP address %s"),
# 3617| daemon->addrbuff);
# 3618|-> return 0;
# 3619| }
# 3620| }
Error: RESOURCE_LEAK (CWE-772): [#def108] [important]
dnsmasq-2.86test7/src/option.c:3781: alloc_fn: Storage is returned from allocation function "opt_malloc".
dnsmasq-2.86test7/src/option.c:3781: var_assign: Assigning: "new" = storage returned from "opt_malloc(32UL)".
dnsmasq-2.86test7/src/option.c:3786: leaked_storage: Variable "new" going out of scope leaks the storage it points to.
# 3784|
# 3785| if (!(comma = split(arg)) || (len = strlen(comma)) == 0)
# 3786|-> ret_err(gen_err);
# 3787|
# 3788| new->wildcard = 0;
Error: RESOURCE_LEAK (CWE-772): [#def109] [important]
dnsmasq-2.86test7/src/option.c:3921: alloc_fn: Storage is returned from allocation function "opt_malloc".
dnsmasq-2.86test7/src/option.c:3921: var_assign: Assigning: "new" = storage returned from "opt_malloc(56UL)".
dnsmasq-2.86test7/src/option.c:3994: leaked_storage: Variable "new" going out of scope leaks the storage it points to.
# 3992| }
# 3993|
# 3994|-> ret_err(gen_err);
# 3995| }
# 3996|
Error: CLANG_WARNING: [#def111]
dnsmasq-2.86test7/src/option.c:4693:25: warning[deadcode.DeadStores]: Value stored to 'tmp' during its initialization is never read
# 4691| if (!canon)
# 4692| {
# 4693|-> struct name_list *tmp = new->names, *next;
# 4694| for (tmp = new->names; tmp; tmp = next)
# 4695|
