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* overhaul internally-public declarations using wrapper headersRich Felker2018-09-121-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commits leading up to this one have moved the vast majority of libc-internal interface declarations to appropriate internal headers, allowing them to be type-checked and setting the stage to limit their visibility. the ones that have not yet been moved are mostly namespace-protected aliases for standard/public interfaces, which exist to facilitate implementing plain C functions in terms of POSIX functionality, or C or POSIX functionality in terms of extensions that are not standardized. some don't quite fit this description, but are "internally public" interfacs between subsystems of libc. rather than create a number of newly-named headers to declare these functions, and having to add explicit include directives for them to every source file where they're needed, I have introduced a method of wrapping the corresponding public headers. parallel to the public headers in $(srcdir)/include, we now have wrappers in $(srcdir)/src/include that come earlier in the include path order. they include the public header they're wrapping, then add declarations for namespace-protected versions of the same interfaces and any "internally public" interfaces for the subsystem they correspond to. along these lines, the wrapper for features.h is now responsible for the definition of the hidden, weak, and weak_alias macros. this means source files will no longer need to include any special headers to access these features. over time, it is my expectation that the scope of what is "internally public" will expand, reducing the number of source files which need to include *_impl.h and related headers down to those which are actually implementing the corresponding subsystems, not just using them.
* declare __getopt_msg in stdio_impl.hRich Felker2018-09-121-2/+1
| | | | | | it's not ideal, but the function is essentially an extended stdio function specialized to getopt's needs. the only reason it exists is avoiding pulling printf code into every program using getopt.
* use lighter internal stdio lock in getopt error printingRich Felker2018-09-121-2/+3
| | | | | | the public flockfile interface is significantly heavier because it has to handle the possibility of caller returning or thread exiting while holding the lock.
* move and deduplicate declarations of __procfdname to make it checkableRich Felker2018-09-121-2/+0
| | | | | | syscall.h was chosen as the header to declare it, since its intended usage is alongside syscalls as a fallback for operations the direct syscall does not support.
* fix issues from public functions defined without declaration visibleRich Felker2018-09-123-0/+5
| | | | | | | | | | | | | | | | | policy is that all public functions which have a public declaration should be defined in a context where that public declaration is visible, to avoid preventable type mismatches. an audit performed using GCC's -Wmissing-declarations turned up the violations corrected here. in some cases the public header had not been included; in others, a feature test macro needed to make the declaration visible had been omitted. in the case of gethostent and getnetent, the omission seems to have been intentional, as a hack to admit a single stub definition for both functions. this kind of hack is no longer acceptable; it's UB and would not fly with LTO or advanced toolchains. the hack is undone to make exposure of the declarations possible.
* getopt: update optarg and optind correctly on missing argumentRich Felker2018-08-221-6/+6
| | | | | | | | | the text of the specification for getopt's handling of options that require an argument, which requires updating optarg and optind, does not exclude the error case where the end of the argument list has been reached. in that case, it is expected that optarg be assigned argv[argc] (normally null) and optind be incremented by 2, resulting in a value of argc+1.
* getopt_long_only: don't prefix-match long-options that match short onesRich Felker2018-04-271-2/+15
| | | | | | | | | | | | | | | | | for getopt_long, partial (prefix) matches of long options always begin with "--" and thus can never be ambiguous with a short option. for getopt_long_only, though, a single-character option can match both a short option and as a prefix for a long option. in this case, we wrongly interpreted it as a prefix for the long option. introduce a new pass, only in long-only mode, to check the prefix match against short options before accepting it. the only reason there's a slightly nontrivial loop being introduced rather than strchr is that our getopt already supports multibyte short options, and getopt_long_long should handle them consistently. a temp buffer and strstr could have been used, but the code to set it up would be just as large as what's introduced here and it would unnecessarily pull in relatively large code for strstr.
* add public interface headers to implementation filesRich Felker2018-02-251-0/+2
| | | | | | | | | general policy is that all source files defining a public API or an ABI mechanism referenced by a public header should include the public header that declares the interface, so that the compiler or analysis tools can check the consistency of the declarations. Alexander Monakov pointed out a number of violations of this principle a few years back. fix them now.
* fix getopt wrongly treating colons in optstring as valid option charsRich Felker2018-02-241-1/+1
| | | | | | | the ':' in optstring has special meaning as a flag applying to the previous option character, or to getopt's error handling behavior when it appears at the beginning. don't also accept a "-:" option based on its presence.
* add getentropy functionRich Felker2018-02-231-0/+31
| | | | | | | based loosely on patch by Hauke Mehrtens; converted to wrap the public API of the underlying getrandom function rather than direct syscalls, so that if/when a fallback implementation of getrandom is added it will automatically get picked up by getentropy too.
* re-fix child reaping in wordexpAlexander Monakov2018-02-051-7/+1
| | | | | | Do not retry waitpid if the child was terminated by a signal. Do not examine status: since we are not passing any flags, we will not receive stop or continue notifications.
* getopt_long: accept prefix match of long options containing equals signsSamuel Holland2018-01-311-1/+2
| | | | | | | | | | | | Consider the first equals sign found in the option to be the delimiter between it and its argument, even if it matches an equals sign in the option name. This avoids consuming the equals sign, which would prevent finding the argument. Instead, it forces a partial match of the part of the option name before the equals sign. Maintainer's note: GNU getopt_long does not explicitly document this behavior, but it can be seen as a consequence of how partial matches are specified, and at least GNU (bfd) ld is known to make use of it.
* fix getopt_long arguments to partial matchesSamuel Holland2018-01-311-1/+3
| | | | | | | If we find a partial option name match, we need to keep looking for ambiguous/conflicting options. However, we need to remember the position in the candidate argument to find its option-argument later, if there is one. This fixes e.g. option "foobar" being given as "--fooba=baz".
* revise the definition of multiple basic locks in the codeJens Gustedt2018-01-091-1/+1
| | | | In all cases this is just a change from two volatile int to one.
* fix incorrect base name offset from nftw when pathname ends in slash(es)Rich Felker2017-10-131-3/+9
| | | | | | | | | | | | | | | the rightmost '/' character is not necessarily the delimiter before the basename; it could be a spurious trailing character on the directory name. this change does not introduce any normalization of pathnames or stripping of trailing slashes, contrary to at least glibc and perhaps other implementations; it jusst prevents their presence from breaking things. whether further changes should be made is an open question that may depend on conformance and/or application compatibility considerations. based loosely on patch by Joakim Sindholt.
* fix getopt[_long] clobbering of optopt on successRich Felker2017-01-042-2/+5
| | | | | | | | | | | | | getopt is only specified to modify optopt on error, and some software apparently infers an error from optopt!=0. getopt_long is changed analogously. the resulting behavior differs slightly from the behavior of the GNU implementation of getopt_long, which keeps an internal shadow copy of optopt and copies it to the public one on return, but since the GNU implementation also exhibits this shadow-copy behavior for plain getopt where is is non-conforming, I think this can reasonably be considered a bug rather than an intentional behavior that merits mimicing.
* fix getopt_long_only misinterpreting "--" as an optionRich Felker2016-10-201-1/+1
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* use dynamic buffer for getmntentNatanael Copa2016-10-201-4/+13
| | | | | | | | | | overlayfs may have fairly long lines so we use getline to allocate a buffer dynamically. The buffer will be allocated on first use, expand as needed, but will never be free'ed. Downstream bug: http://bugs.alpinelinux.org/issues/5703 Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
* fix a64l undefined behavior on ILP32 archs, wrong results on LP64 archsRich Felker2016-05-231-3/+6
| | | | | | | | | | | | | | | | | | | the difference of pointers is a signed type ptrdiff_t; if it is only 32-bit, left-shifting it by 30 bits produces undefined behavior. cast the difference to an appropriate unsigned type, uint32_t, before shifting to avoid this. the a64l function is specified to return a signed 32-bit result in type long. as noted in the bug report by Ed Schouten, converting implicitly from uint32_t only produces the desired result when long is a 32-bit type. since the computation has to be done in unsigned arithmetic to avoid overflow, simply cast the result to int32_t. further, POSIX leaves the behavior on invalid input unspecified but not undefined, so we should not take the difference between the potentially-null result of strchr and the base pointer without first checking the result. the simplest behavior is just returning the partial conversion already performed in this case, so do that.
* fix unlikely corner cases in getopt's message printingRich Felker2016-02-161-2/+2
| | | | | | | | | | | | like fputs (see commit 10a17dfbad2c267d885817abc9c7589fc7ff630b), the message printing code for getopt assumed that fwrite only returns 0 on failure, but it can also happen on success if the total length to be written is zero. programs with zero-length argv[0] were affected. commit 500c6886c654fd45e4926990fee2c61d816be197 introduced this problem in getopt by fixing the fwrite behavior to conform to the requirements of ISO C. previously the wrong expectations of the getopt code were met by the fwrite implementation.
* getsubopt: don't include leading = in value stringSteven Barth2015-08-211-1/+1
| | | | | | | getsubopt incorrectly returns the delimiting = in the value string, this patch fixes it by increasing the pointer position by one. Signed-off-by: Steven Barth <cyrus@openwrt.org>
* handle loss of syslog socket connectionRich Felker2015-07-091-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | when traditional syslogd implementations are restarted, the old server socket ceases to exist and a new unix socket with the same pathname is created. when this happens, the default destination address associated with the client socket via connect is no longer valid, and attempts to send produce errors. this happens despite the socket being datagram type, and is in contrast to the behavior that would be seen with an IP datagram (UDP) socket. in order to avoid a situation where the application is unable to send further syslog messages without calling closelog, this patch makes syslog attempt to reconnect the socket when send returns an error indicating a lost connection. additionally, initial failure to connect the socket no longer results in the socket being closed. this ensures that an application which calls openlog to reserve the socket file descriptor will not run into a situation where transient connection failure (e.g. due to syslogd restart) prevents fd reservation. however, applications which may be unable to connect the socket later (e.g. due to chroot, restricted permissions, seccomp, etc.) will still fail to log if the syslog socket cannot be connected at openlog time or if it has to be reconnected later.
* add alternate backend support for getgrouplistJosiah Worcester2015-03-151-24/+0
| | | | | | | | | | | | | | | | | This completes the alternate backend support that was previously added to the getpw* and getgr* functions. Unlike those, though, it unconditionally queries nscd. Any groups from nscd that aren't in the /etc/groups file are added to the returned list, and any that are present in the file are ignored. The purpose of this behavior is to provide a view of the group database consistent with what is observed by the getgr* functions. If group memberships reported by nscd were honored when the corresponding group already has a definition in the /etc/groups file, the user's getgrouplist-based membership in the group would conflict with their non-membership in the reported gr_mem[] for the group. The changes made also make getgrouplist thread-safe and eliminate its clobbering of the global getgrent state.
* eliminate atomics in syslog setlogmask functionRich Felker2015-03-041-4/+6
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* make all objects used with atomic operations volatileRich Felker2015-03-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the memory model we use internally for atomics permits plain loads of values which may be subject to concurrent modification without requiring that a special load function be used. since a compiler is free to make transformations that alter the number of loads or the way in which loads are performed, the compiler is theoretically free to break this usage. the most obvious concern is with atomic cas constructs: something of the form tmp=*p;a_cas(p,tmp,f(tmp)); could be transformed to a_cas(p,*p,f(*p)); where the latter is intended to show multiple loads of *p whose resulting values might fail to be equal; this would break the atomicity of the whole operation. but even more fundamental breakage is possible. with the changes being made now, objects that may be modified by atomics are modeled as volatile, and the atomic operations performed on them by other threads are modeled as asynchronous stores by hardware which happens to be acting on the request of another thread. such modeling of course does not itself address memory synchronization between cores/cpus, but that aspect was already handled. this all seems less than ideal, but it's the best we can do without mandating a C11 compiler and using the C11 model for atomics. in the case of pthread_once_t, the ABI type of the underlying object is not volatile-qualified. so we are assuming that accessing the object through a volatile-qualified lvalue via casts yields volatile access semantics. the language of the C standard is somewhat unclear on this matter, but this is an assumption the linux kernel also makes, and seems to be the correct interpretation of the standard.
* fix bad character checking in wordexpRich Felker2015-02-111-0/+1
| | | | | | | | | the character sequence '$((' was incorrectly interpreted as the opening of arithmetic even within single-quoted contexts, thereby suppressing the checks for bad characters after the closing quote. presently bad character checking is only performed when the WRDE_NOCMD is used; this patch only corrects checking in that case.
* simplify part of getopt_longRich Felker2015-01-211-13/+11
| | | | | | | as a result of commit e8e4e56a8ce1f3d7e4a027ff5478f2f8ea70c46b, the later code path for setting optarg to a null pointer is no longer necessary, and removing it eliminates an indention level and arguably makes the code more readable.
* always set optarg in getopt_longRich Felker2015-01-211-1/+1
| | | | | | | | | | | the standard getopt does not touch optarg unless processing an option with an argument. however, programs using the GNU getopt API, which we attempt to provide in getopt_long, expect optarg to be a null pointer after processing an option without an argument. before argument permutation support was added, such programs typically detected its absence and used their own replacement getopt_long, masking the discrepency in behavior.
* for multithreaded set*id/setrlimit, handle case where callback does not runRich Felker2015-01-151-3/+3
| | | | | | | | in the current version of __synccall, the callback is always run, so failure to handle this case did not matter. however, the upcoming overhaul of __synccall will have failure cases, in which case the callback does not run and errno is already set. the changes being committed now are in preparation for that.
* increase syslog message limit from 256 to 1024Rich Felker2015-01-131-1/+1
| | | | | this addresses alpine linux issue #3692 and brings the syslog message length limit in alignment with uclibc's implementation.
* fix regression in getopt_long support for non-option argumentsRich Felker2015-01-111-7/+6
| | | | | | | | | | | | | | | | commit b72cd07f176b876aa51864d93aa8101477b1d732 added support for a this feature in getopt, but it was later broken in the case where getopt_long is used as a side effect of the changes made in commit 91184c4f16b143107fa9935edebe5d2b20bd70d8, which prevented the underlying getopt call from seeing the leading '-' or '+' character in optstring. this commit changes the logic in the getopt_long core to check for a leading colon, possibly after the leading '-' or '+', without depending on the latter having been skipped by the caller. a minor incorrectness in the return value for one error condition in getopt_long is also fixed when opterr has been set to zero but optstring has no leading ':'.
* check for connect failure in syslog log openingRich Felker2015-01-091-2/+6
| | | | | | | based on patch by Dima Krasner, with minor improvements for code size. connect can fail if there is no listening syslogd, in which case a useless socket was kept open, preventing subsequent syslog call from attempting to connect again.
* overhaul forkpty function using new login_ttyRich Felker2014-12-211-26/+45
| | | | | | | | | | | | | | | | | based on discussion with and patches by Felix Janda. these changes started as an effort to factor forkpty in terms of login_tty, which returns an error and skips fd reassignment and closing if setting the controlling terminal failed. the previous forkpty code was unable to handle errors in the child, and did not attempt to; it just silently ignored them. but this would have been unacceptable when switching to using login_tty, since the child would start with the wrong stdin, stdout, and stderr and thereby clobber the parent's files. the new code uses the same technique as the posix_spawn implementation to convey any possible error in the child to the parent so that the parent can report failure to the caller. it is also safe against thread cancellation and against signal delivery in the child prior to the determination of success.
* block pthread cancellation in openpty functionRich Felker2014-12-201-9/+14
| | | | | | | being a nonstandard function, this isn't strictly necessary, but it's inexpensive and avoids unpleasant surprises. eventually I would like all functions in libc to be safe against cancellation, either ignoring it or acting on it cleanly.
* don't write openpty results until success is determinedRich Felker2014-12-201-10/+12
| | | | | | not only is this semantically more correct; it also reduces code size slightly by eliminating the need for the compiler to assume the possibility of aliasing.
* add login_tty functionFelix Janda2014-12-201-0/+14
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* set optopt in getopt_longRich Felker2014-12-201-0/+1
| | | | | | this is undocumented but possibly expected behavior of GNU getopt_long, and useful when error message printing has been suppressed.
* add error message printing to getopt_long and make related improvementsRich Felker2014-12-202-6/+32
| | | | | some related changes are also made to getopt, and the return value of getopt_long in the case of missing arguments is fixed.
* support translation for getopt error messagesRich Felker2014-12-201-0/+2
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* fix stderr locking and ferror semantics in getopt message printingRich Felker2014-12-191-12/+16
| | | | | | | | | | if writing the error message fails, POSIX requires that ferror(stderr) be set. and as a function that operates on a stdio stream, getopt is required to lock the stream it uses, stderr. fwrite calls are used instead of fprintf since there is a demand from some users not to pull in heavy stdio machinery via getopt. this mimics the original code using write.
* simplify getopt_long argv permutation loop logicRich Felker2014-12-131-3/+1
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* fix handling of "--" with getopt_long argv permutationRich Felker2014-12-131-1/+0
| | | | | | if argv permutation is used, the option terminator "--" should be moved before any skipped non-option arguments rather than being left in the argv tail where the caller will see and interpret it.
* accept null longopts pointer in getopt_longRich Felker2014-12-111-1/+1
| | | | | this is an undocumented feature of GNU getopt_long that the BSD version also mimics, and is reportedly needed by some programs.
* fix getopt handling of initial '+' in optstringRich Felker2014-12-101-1/+1
| | | | | | | in the case where an initial '+' was passed in optstring (a getopt_long feature to suppress argv permutation), getopt would fail to see a possible subsequent ':', resulting in incorrect handling of missing arguments.
* support abbreviated options in getopt_longRich Felker2014-12-101-7/+18
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* support options after non-option arguments in getopt_long (argv permutation)Rich Felker2014-12-101-0/+39
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* fix getopt handling of ':' modifier for multibyte option charactersRich Felker2014-12-041-4/+9
| | | | | | | | | the previous hard-coded offsets of +1 and +2 contained a hidden assumption that the option character matched was single-byte, despite this implementation of getopt attempting to support multibyte option characters. this patch reworks the matching logic to leave the final index pointing just past the matched character so that fixed offsets can be used to check for ':'.
* add support for non-option arguments extension to getoptGianluca Anzolin2014-12-022-4/+20
| | | | | | | this is a GNU extension, activated by including '-' as the first character of the options string, whereby non-option arguments are processed as if they were arguments to an option character '\1' rather than ending option processing.
* getopt: fix optional argument processingFelix Fietkau2014-11-151-2/+2
| | | | | | | Processing an option character with optional argument fails if the option is last on the command line. This happens because the if (optind >= argc) check runs first before testing for optional argument.
* make endmntent function handle null argumentTimo Teräs2014-08-081-1/+1
| | | | | The function originates from SunOS 4.x in which the null argument is allowed. glibc also handles this case.