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2024-11-25Silence most -Wzero-as-null-pointer-constant diagnosticsAlejandro Colomar4-12/+12
Replace 0 by NULL and {0} by {}. Omit a few cases that aren't so trivial to fix. Link: <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117059> Link: <https://software.codidact.com/posts/292718/292759#answer-292759> Signed-off-by: Alejandro Colomar <alx@kernel.org>
2024-08-01resolv: Fix tst-resolv-short-response for older GCC (bug 32042)Florian Weimer1-2/+4
Previous GCC versions do not support the C23 change that allows labels on declarations. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-07-24resolv: Implement strict-error stub resolver option (bug 27929)Florian Weimer5-36/+74
For now, do not enable this mode by default due to the potential impact on compatibility with existing deployments. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-07-24resolv: Support clearing option flags with a “-” prefix (bug 14799)Florian Weimer2-13/+25
I think using a “-” prefix is less confusing than introducing double-negation construct (“no-no-tld-query”). Reviewed-by: DJ Delorie <dj@redhat.com>
2024-07-24resolv: Do not wait for non-existing second DNS response after error (bug 30081)Florian Weimer4-1/+149
In single-request mode, there is no second response after an error because the second query has not been sent yet. Waiting for it introduces an unnecessary timeout. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-07-24resolv: Allow short error responses to match any query (bug 31890)Florian Weimer3-10/+134
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-06-13resolv: Track single-request fallback via _res._flags (bug 31476)Florian Weimer2-5/+9
This avoids changing _res.options, which inteferes with change detection as part of automatic reloading of /etc/resolv.conf. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-05-20resolv: Make _res_opcodes a compat symbol [BZ #31764]H.J. Lu1-0/+1
_res_opcodes was exported by accident as a variable. Fix BZ #31764 by making _res_opcodes a compat symbol. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
2024-04-02Always define __USE_TIME_BITS64 when 64 bit time_t is usedAdhemerval Zanella1-1/+1
It was raised on libc-help [1] that some Linux kernel interfaces expect the libc to define __USE_TIME_BITS64 to indicate the time_t size for the kABI. Different than defined by the initial y2038 design document [2], the __USE_TIME_BITS64 is only defined for ABIs that support more than one time_t size (by defining the _TIME_BITS for each module). The 64 bit time_t redirects are now enabled using a different internal define (__USE_TIME64_REDIRECTS). There is no expected change in semantic or code generation. Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, and arm-linux-gnueabi [1] https://sourceware.org/pipermail/libc-help/2024-January/006557.html [2] https://sourceware.org/glibc/wiki/Y2038ProofnessDesign Reviewed-by: DJ Delorie <dj@redhat.com>
2024-02-01Refer to C23 in place of C2X in glibcJoseph Myers1-1/+1
WG14 decided to use the name C23 as the informal name of the next revision of the C standard (notwithstanding the publication date in 2024). Update references to C2X in glibc to use the C23 name. This is intended to update everything *except* where it involves renaming files (the changes involving renaming tests are intended to be done separately). In the case of the _ISOC2X_SOURCE feature test macro - the only user-visible interface involved - support for that macro is kept for backwards compatibility, while adding _ISOC23_SOURCE. Tested for x86_64.
2024-01-26Relicense IBM portions of resolv/base64.c resolv/res_debug.c.Carlos O'Donell2-38/+34
This change relicenses the IBM portions of resolv/base64.c and resolv/res_debug.c to a new license that does not have use-limited patent language. The top-level LICENSE file is updated with the license. The relicensing was approved by IBM. Signed-off-by: Brad Topol, IBM Director of Open Technologies <btopol@us.ibm.com> Signed-off-by: Richard Fontana <rfontana@redhat.com> Signed-off-by: Carlos O'Donell <carlos@redhat.com>
2024-01-11resolv: Fix endless loop in __res_context_queryStefan Liebler2-4/+8
Starting with commit 40c0add7d48739f5d89ebba255c1df26629a76e2 "resolve: Remove __res_context_query alloca usage" there is an endless loop in __res_context_query if __res_context_mkquery fails e.g. if type is invalid. Then the scratch buffer is resized to MAXPACKET size and it is retried again. Before the mentioned commit, it was retried only once and with the mentioned commit, there is no check and it retries in an endless loop. This is observable with xtest resolv/tst-resolv-qtypes which times out after 300s. This patch retries mkquery only once as before the mentioned commit. Furthermore, scratch_buffer_set_array_size is now only called with nelem=2 if type is T_QUERY_A_AND_AAAA (also see mentioned commit). The test tst-resolv-qtypes is also adjusted to verify that <func> is really returning with -1 in case of an invalid type. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert97-97/+97
2023-12-12resolv: Fix a few unaligned accesses to fields in HEADERLudwig Rydberg2-6/+6
After refactoring the alloca usage in 40c0add7d4 ("resolve: Remove __res_context_query alloca usage") a few unaligned accesses to HEADER fields surfaced. These unaligned accesses led to problems when running the resolv test suite on sparc32-linux (leon) as many tests failed due to SIGBUS crashes. The issue(s) occured during T_QUERY_A_AND_AAAA queries as the second query now can start on an unaligned address (previously it was explicitly aligned). With this patch the unaligned accesses are now fixed by using the UHEADER instead to ensure the fields are accessed with byte loads/stores. The patch has been verfied by running the resolv test suite on sparc32 and x86_64. Signed-off-by: Ludwig Rydberg <ludwig.rydberg@gaisler.com> Signed-off-by: Andreas Larsson <andreas@gaisler.com> Reviewed-by: Florian Weimer <fweimer@redhat.com>
2023-11-20resolv: free only initialized items from gai poolJan Palus1-1/+2
pool_max_size denotes total allocated rows in pool but possibly not yet initialized. it's pool_size that represents number of actually occupied rows hence use it when freeing pool to avoid freeing random addresses. Signed-off-by: Jan Palus <jpalus@fastmail.com> Reviewed-by: Florian Weimer <fweimer@redhat.com>
2023-10-02resolve: Remove __res_context_query alloca usageAdhemerval Zanella1-31/+23
The bufsize on current Linux build is: size_t bufsize = (type == 439963904 ? 2 : 1) * (12 + 4 + 255 + 1); So with upper bound as 544 (2 * (12 + 4 + 255 + 1)). However, it might increase to 2 * PACKETSIZE later with malloc. The default scratch_buffer should fullfill the most usual allocation requirement. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: Joe Simmons-Talbott <josimmon@redhat.com>
2023-09-29resolv: Fix a comment typo in __resolv_conf_loadArjun Shankar1-1/+1
The file being referred to is host.conf, not hosts.conf.
2023-09-13CVE-2023-4527: Stack read overflow with large TCP responses in no-aaaa modeFlorian Weimer3-1/+132
Without passing alt_dns_packet_buffer, __res_context_search can only store 2048 bytes (what fits into dns_packet_buffer). However, the function returns the total packet size, and the subsequent DNS parsing code in _nss_dns_gethostbyname4_r reads beyond the end of the stack-allocated buffer. Fixes commit f282cdbe7f436c75864e5640a4 ("resolv: Implement no-aaaa stub resolver option") and bug 30842.
2023-09-13resolv: Fix some unaligned accesses in resolver [BZ #30750]John David Anglin2-2/+4
Signed-off-by: John David Anglin <dave.anglin@bell.net>
2023-08-14resolv/nss_dns/dns-host: Get rid of alloca.Joe Simmons-Talbott1-2/+2
Since the alloca is a small constant size use an array instead. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-07-24Restore lookup of IPv4 mapped addresses in files database (bug 25457)Andreas Schwab1-0/+69
This was broken by commit 9c02d0784d ("nss_files: Remove RES_USE_INET6 from hosts processing"), which removed too much.
2023-06-07resolv_conf: release lock on allocation failure (bug 30527)Andreas Schwab1-1/+4
When the initial allocation of global fails, the local lock is left locked. Reported by Steffen Lammel of SAP HANA development.
2023-06-02Fix all the remaining misspellings -- BZ 25337Paul Pluzhnikov20-28/+28
2023-05-19hurd 64bit: Re-introduce gai_suspend symbolSamuel Thibault1-0/+2
4d3f846b88d3 ("hurd: Fix __TIMESIZE on x86_64") incidentaly dropped it because it fixed hurd 64bit into setting __TIMESIZE to 64, and that case was not having gai_suspend defined yet.
2023-05-01hurd 64bit: Add missing libanlSamuel Thibault1-1/+1
The move of libanl to libc was in glibc 2.34 for nptl only.
2023-03-27Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functionsAdhemerval Zanella Netto6-17/+26
They are both used by __libc_freeres to free all library malloc allocated resources to help tooling like mtrace or valgrind with memory leak tracking. The current scheme uses assembly markers and linker script entries to consolidate the free routine function pointers in the RELRO segment and to be freed buffers in BSS. This patch changes it to use specific free functions for libc_freeres_ptrs buffers and call the function pointer array directly with call_function_static_weak. It allows the removal of both the internal macros and the linker script sections. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-02-16C2x strtol binary constant handlingJoseph Myers3-1/+32
C2x adds binary integer constants starting with 0b or 0B, and supports those constants in strtol-family functions when the base passed is 0 or 2. Implement that strtol support for glibc. As discussed at <https://sourceware.org/pipermail/libc-alpha/2020-December/120414.html>, this is incompatible with previous C standard versions, in that such an input string starting with 0b or 0B was previously required to be parsed as 0 (with the rest of the string unprocessed). Thus, as proposed there, this patch adds 20 new __isoc23_* functions with appropriate header redirection support. This patch does *not* do anything about scanf %i (which will need 12 new functions per long double variant, so 12, 24 or 36 depending on the glibc configuration), instead leaving that for a future patch. The function names would remain as __isoc23_* even if C2x ends up published in 2024 rather than 2023. Making this change leads to the question of what should happen to internal uses of these functions in glibc and its tests. The header redirection (which applies for _GNU_SOURCE or any other feature test macros enabling C2x features) has the effect of redirecting internal uses but without those uses then ending up at a hidden alias (see the comment in include/stdio.h about interaction with libc_hidden_proto). It seems desirable for the default for internal uses to be the same versions used by normal code using _GNU_SOURCE, so rather than doing anything to disable that redirection, similar macro definitions to those in include/stdio.h are added to the include/ headers for the new functions. Given that the default for uses in glibc is for the redirections to apply, the next question is whether the C2x semantics are correct for all those uses. Uses with the base fixed to 10, 16 or any other value other than 0 or 2 can be ignored. I think this leaves the following internal uses to consider (an important consideration for review of this patch will be both whether this list is complete and whether my conclusions on all entries in it are correct): benchtests/bench-malloc-simple.c benchtests/bench-string.h elf/sotruss-lib.c math/libm-test-support.c nptl/perf.c nscd/nscd_conf.c nss/nss_files/files-parse.c posix/tst-fnmatch.c posix/wordexp.c resolv/inet_addr.c rt/tst-mqueue7.c soft-fp/testit.c stdlib/fmtmsg.c support/support_test_main.c support/test-container.c sysdeps/pthread/tst-mutex10.c I think all of these places are OK with the new semantics, except for resolv/inet_addr.c, where the POSIX semantics of inet_addr do not allow for binary constants; thus, I changed that file (to use __strtoul_internal, whose semantics are unchanged) and added a test for this case. In the case of posix/wordexp.c I think accepting binary constants is OK since POSIX explicitly allows additional forms of shell arithmetic expressions, and in stdlib/fmtmsg.c SEV_LEVEL is not in POSIX so again I think accepting binary constants is OK. Functions such as __strtol_internal, which are only exported for compatibility with old binaries from when those were used in inline functions in headers, have unchanged semantics; the __*_l_internal versions (purely internal to libc and not exported) have a new argument to specify whether to accept binary constants. As well as for the standard functions, the header redirection also applies to the *_l versions (GNU extensions), and to legacy functions such as strtoq, to avoid confusing inconsistency (the *q functions redirect to __isoc23_*ll rather than needing their own __isoc23_* entry points). For the functions that are only declared with _GNU_SOURCE, this means the old versions are no longer available for normal user programs at all. An internal __GLIBC_USE_C2X_STRTOL macro is used to control the redirections in the headers, and cases in glibc that wish to avoid the redirections - the function implementations themselves and the tests of the old versions of the GNU functions - then undefine and redefine that macro to allow the old versions to be accessed. (There would of course be greater complexity should we wish to make any of the old versions into compat symbols / avoid them being defined at all for new glibc ABIs.) strtol_l.c has some similarity to strtol.c in gnulib, but has already diverged some way (and isn't listed at all at https://sourceware.org/glibc/wiki/SharedSourceFiles unlike strtoll.c and strtoul.c); I haven't made any attempts at gnulib compatibility in the changes to that file. I note incidentally that inttypes.h and wchar.h are missing the __nonnull present on declarations of this family of functions in stdlib.h; I didn't make any changes in that regard for the new declarations added.
2023-01-06Update copyright dates with scripts/update-copyrightsJoseph Myers95-95/+95
2022-12-19Avoid use of atoi in some places in libcJoseph Myers1-3/+3
This patch is split out of <https://sourceware.org/pipermail/libc-alpha/2022-December/144122.html>. atoi has undefined behavior on out-of-range input, which makes it problematic to use anywhere in glibc that might be processing input out-of-range for atoi but not specified to produce undefined behavior for the function calling atoi. Change some uses of atoi to call strtol instead; this avoids the undefined behavior, though there is no guarantee that the overflow handling of strtol is really right in those places either. This also serves to avoid localplt test failures given an installed header redirection for strtol (which means that the call from the inline atoi implementation doesn't end up at a hidden alias from libc_hidden_proto). Certainly, the use of atoi is questionable in argp-help.c (shared with gnulib, so shouldn't depend on glibc implementation details, and processing user-provided input), and maybe also in argp-parse.c (I'm not sure what that code in argp-parse.c is meant to be used for). I also changed inet/rexec.c and resolv/res_init.c similarly to use strtol to avoid such localplt failures, although given those files (in those versions) are only used in glibc it's not problematic for them to rely on the specific behavior of glibc's atoi on out-of-range input (in the absence of compiler optimizations based on the undefined behavior) in the same way it's problematic for gnulib code to do so. There may be other uses of atoi (or atol or atoll), in any of glibc's installed code, for which it would also be appropriate to avoid the undefined behavior on out-of-range input; this patch only fixes the specific cases needed to avoid localplt failures. Tested for x86_64.
2022-11-01configure: Use -Wno-ignored-attributes if compiler warns about multiple aliasesAdhemerval Zanella1-0/+1
clang emits an warning when a double alias redirection is used, to warn the the original symbol will be used even when weak definition is overridden. However, this is a common pattern for weak_alias, where multiple alias are set to same symbol. Reviewed-by: Fangrui Song <maskray@google.com>
2022-08-30resolv: Fix building tst-resolv-invalid-cname for earlier C standardsFlorian Weimer1-1/+1
This fixes this compiler error: tst-resolv-invalid-cname.c: In function ‘test_mode_to_string’: tst-resolv-invalid-cname.c:164:10: error: label at end of compound statement case test_mode_num: ^~~~~~~~~~~~~ Fixes commit 9caf782276ecea4bc86fc94fbb52779736f3106d ("resolv: Add new tst-resolv-invalid-cname").
2022-08-30nss_dns: Rewrite _nss_dns_gethostbyname4_r using current interfacesFlorian Weimer1-281/+162
Introduce struct alloc_buffer to this function, and use it and struct ns_rr_cursor in gaih_getanswer_slice. Adjust gaih_getanswer and gaih_getanswer_noaaaa accordingly. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add new tst-resolv-invalid-cnameFlorian Weimer2-0/+409
This test checks resolution through CNAME chains that do not contain host names (bug 12154). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30nss_dns: In gaih_getanswer_slice, skip strange aliases (bug 12154)Florian Weimer1-4/+4
If the name is not a host name, skip adding it to the result, instead of reporting query failure. This fixes bug 12154 for getaddrinfo. This commit still keeps the old parsing code, and only adjusts when a host name is copied. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30nss_dns: Rewrite getanswer_r to match getanswer_ptr (bug 12154, bug 29305)Florian Weimer1-298/+180
Allocate the pointer arrays only at the end, when their sizes are known. This addresses bug 29305. Skip over invalid names instead of failing lookups. This partially fixes bug 12154 (for gethostbyname, fixing getaddrinfo requires different changes). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30nss_dns: Remove remnants of IPv6 address mappingFlorian Weimer4-201/+9
res_use_inet6 always returns false since commit 3f8b44be0a658266adff5 ("resolv: Remove support for RES_USE_INET6 and the inet6 option"). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30nss_dns: Rewrite _nss_dns_gethostbyaddr2_r and getanswer_ptrFlorian Weimer1-303/+102
The simplification takes advantage of the split from getanswer_r. It fixes various aliases issues, and optimizes NSS buffer usage. The new DNS packet parsing helpers are used, too. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30nss_dns: Split getanswer_ptr from getanswer_rFlorian Weimer1-52/+268
And expand the use of name_ok and qtype in getanswer_ptr (the former also in getanswer_r). After further cleanups, not much code will be shared between the two functions. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add DNS packet parsing helpers geared towards wire formatFlorian Weimer4-0/+369
The public parser functions around the ns_rr record type produce textual domain names, but usually, this is not what we need while parsing DNS packets within glibc. This commit adds two new helper functions, __ns_rr_cursor_init and __ns_rr_cursor_next, for writing packet parsers, and struct ns_rr_cursor, struct ns_rr_wire as supporting types. In theory, it is possible to avoid copying the owner name into the rname field in __ns_rr_cursor_next, but this would need more functions that work on compressed names. Eventually, __res_context_send could be enhanced to preserve the result of the packet parsing that is necessary for matching the incoming UDP packets, so that this works does not have to be done twice. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add internal __ns_name_length_uncompressed functionFlorian Weimer3-0/+212
This function is useful for checking that the question name is uncompressed (as it should be). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add the __ns_samebinaryname functionFlorian Weimer3-0/+122
During packet parsing, only the binary name is available. If the name equality check is performed before conversion to text, we can sometimes skip the last step. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add internal __res_binary_hnok functionFlorian Weimer1-5/+9
During package parsing, only the binary representation is available, and it is convenient to check that directly for conformance with host name requirements. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add tst-resolv-aliasesFlorian Weimer2-0/+256
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-08-30resolv: Add tst-resolv-byaddr for testing reverse lookupFlorian Weimer3-0/+360
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-06-24resolv/tst-resolv-noaaaa: Support building for older C standardsFlorian Weimer1-5/+9
This avoids a compilation error: tst-resolv-noaaaa.c: In function 'response': tst-resolv-noaaaa.c:74:11: error: a label can only be part of a statement and a declaration is not a statement char ipv4[4] = {192, 0, 2, i + 1}; ^~~~ tst-resolv-noaaaa.c:79:11: error: a label can only be part of a statement and a declaration is not a statement char *name = xasprintf ("ptr-%d", i); ^~~~
2022-06-24resolv: Implement no-aaaa stub resolver optionFlorian Weimer11-12/+773
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-04-13Replace {u}int_fast{16|32} with {u}int32_tNoah Goldstein1-1/+1
On 32-bit machines this has no affect. On 64-bit machines {u}int_fast{16|32} are set as {u}int64_t which is often not ideal. Particularly x86_64 this change both saves code size and may save instruction cost. Full xcheck passes on x86_64.
2022-03-31resolv: Initialize loop variable on tst-resolv-trailingAdhemerval Zanella1-1/+1
Checked on x86_64-linux-gnu and i686-linux-gnu.
2022-03-22resolv: Fix unaligned accesses to fields in HEADER structJohn David Anglin3-14/+21
The structure HEADER is normally aligned to a word boundary but sometimes it needs to be accessed when aligned on a byte boundary. This change defines a new typedef, UHEADER, with alignment 1. It is used to ensure the fields are accessed with byte loads and stores when necessary. V4: Change to res_mkquery.c deleted. Small whitespace fix. V5: Move UHEADER typedef to resolv/resolv-internal.h. Replace all HEADER usage with UHEADER in resolv/res_send.c. Signed-off-by: John David Anglin <dave.anglin@bell.net> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2022-02-24resolv: Fix tst-resolv tests for 2.35 ABIs and laterStafford Horne1-9/+9
The commit 737e873b30 ("resolv: Do not build libanl.so for ABIs starting at 2.35") disabled building libanl for ports supporting only 2.35 and later like OpenRISC. However, the if statement was not updated quite correctly and the change ends up disabling many tst-resolv* tests. This was not supposed to be done and it causes test dependency errors like: make: Entering directory 'gnu-home/glibc/resolv' make: *** No rule to make target 'gnu-home/build-glibc/resolv/tst-resolv-res_ninit.out', needed by 'gnu-home/build-glibc/resolv/mtrace-tst-resolv-res_ninit.out'. Stop. make: Leaving directory 'gnu-home/glibc/resolv' This patch move the extra-libs += libanl definition and condition down to be closer to other libanl definitions. The $(have-GLIBC_2.34) condition now includes libanl-routines and libanl-shared-only-routines as well. Also, I have added a comment to endif of $(have-thread-library) to help show the bondary of the have-thread-library definitions. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>