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.Dd May 16, 2024 .Dt CAPSICUM_HELPERS 3 .Os .Sh NAME .Nm caph_limit_stream , .Nm caph_limit_stdin , .Nm caph_limit_stderr , .Nm caph_limit_stdout , .Nm caph_limit_stdio , .Nm caph_stream_rights , .Nm caph_cache_tzdata , .Nm caph_cache_catpages , .Nm caph_enter , .Nm caph_enter_casper , .Nm caph_rights_limit , .Nm caph_ioctls_limit , .Nm caph_fcntls_limit .Nd "set of the capsicum helpers, part of the libcapsicum" .Sh LIBRARY .Lb libcapsicum .Sh SYNOPSIS n capsicum_helpers.h .Ft int .Fn caph_enter "void" .Ft int .Fn caph_enter_casper "void" .Ft int .Fn caph_rights_limit "int fd" "const cap_rights_t *rights" .Ft int .Fn caph_ioctls_limit "int fd" "const unsigned long *cmds" "size_t ncmds" .Ft int .Fn caph_fcntls_limit "int fd" "uint32_t fcntlrights" .Ft int .Fn caph_limit_stream "int fd" "int flags" .Ft int .Fn caph_limit_stdin "void" .Ft int .Fn caph_limit_stderr "void" .Ft int .Fn caph_limit_stdout "void" .Ft int .Fn caph_limit_stdio "void" .Ft void .Fn caph_stream_rights "cap_rights_t *" "int flags" .Ft void .Fn caph_cache_tzdata "void" .Ft void .Fn caph_cache_catpages "void" .Sh DESCRIPTION The .Nm caph_enter , .Nm caph_rights_limit , .Nm caph_ioctls_limit and .Nm caph_fcntls_limit are respectively equivalent to .Xr cap_enter 2 , .Xr cap_rights_limit 2 , .Xr cap_ioctls_limit 2 and .Xr cap_fcntls_limit 2 , it returns success when the kernel is built without support of the capability mode.
p The .Nm caph_enter_casper is equivalent to the .Nm caph_enter it returns success when the system is built without Casper support.
p The .Nm capsicum helpers are a set of a inline functions which simplify modifying programs to use Capsicum. The goal is to reduce duplicated code patterns. The .Nm capsicum helpers are part of .Nm libcapsicum but there is no need to link to the library.
p .Fn caph_limit_stream restricts capabilities on .Fa fd to only those needed by POSIX stream objects (that is, FILEs).
p These flags can be provided:
p l -tag -width "CAPH_IGNORE_EBADF" -compact -offset indent t Dv CAPH_IGNORE_EBADF Do not return an error if file descriptor is invalid. t Dv CAPH_READ Set CAP_READ on limited descriptor. t Dv CAPH_WRITE Set CAP_WRITE on limited descriptor. .El
p .Fn caph_limit_stdin , .Fn caph_limit_stderr and .Fn caph_limit_stdout limit standard descriptors using the .Nm caph_limit_stream function.
p .Fn caph_limit_stdio limits stdin, stderr and stdout.
p .Nm caph_stream_rights may be used to initialize .Fa rights with the same rights that a stream would be limited to, as if .Fn caph_limit_stream had been invoked using the same .Fa flags .
p .Fn caph_cache_tzdata precaches all timezone data needed to use .Li libc local time functions.
p .Fn caph_cache_catpages caches Native Language Support (NLS) data. NLS data is used for localized error printing by .Xr strerror 3 and .Xr err 3 , among others. .Sh RETURN VALUES Upon successful completion, .Fn caph_enter , .Fn caph_enter_casper , .Fn caph_rights_limit , .Fn caph_ioctls_limit , .Fn caph_fcntls_limit , .Fn caph_limit_stream , .Fn caph_limit_stdin , .Fn caph_limit_stderr , .Fn caph_limit_stdout , and .Fn caph_limit_stdio return a value of 0. Otherwise, a value of -1 is returned and the global variable .Va errno is set to indicate the error.
p Functions .Fn caph_stream_rights , .Fn caph_cache_tzdata , and .Fn caph_cache_catpages can not fail. .Ed .Sh SEE ALSO .Xr cap_enter 2 , .Xr cap_rights_limit 2 , .Xr rights 4