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Diffstat (limited to 'src/util/open_limit.c')
-rw-r--r-- | src/util/open_limit.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/util/open_limit.c b/src/util/open_limit.c new file mode 100644 index 0000000..8d49433 --- /dev/null +++ b/src/util/open_limit.c @@ -0,0 +1,100 @@ +/*++ +/* NAME +/* open_limit 3 +/* SUMMARY +/* set/get open file limit +/* SYNOPSIS +/* #include <iostuff.h> +/* +/* int open_limit(int limit) +/* DESCRIPTION +/* The \fIopen_limit\fR() routine attempts to change the maximum +/* number of open files to the specified limit. Specify a null +/* argument to effect no change. The result is the actual open file +/* limit for the current process. The number can be smaller or larger +/* than the requested limit. +/* DIAGNOSTICS +/* open_limit() returns -1 in case of problems. The errno +/* variable gives hints about the nature of the problem. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System libraries. */ + +#include "sys_defs.h" +#include <sys/time.h> +#include <sys/resource.h> +#include <errno.h> + +#ifdef USE_MAX_FILES_PER_PROC +#include <sys/sysctl.h> +#define MAX_FILES_PER_PROC "kern.maxfilesperproc" +#endif + +/* Application-specific. */ + +#include "iostuff.h" + + /* + * 44BSD compatibility. + */ +#ifndef RLIMIT_NOFILE +#ifdef RLIMIT_OFILE +#define RLIMIT_NOFILE RLIMIT_OFILE +#endif +#endif + +/* open_limit - set/query file descriptor limit */ + +int open_limit(int limit) +{ +#ifdef RLIMIT_NOFILE + struct rlimit rl; +#endif + + if (limit < 0) { + errno = EINVAL; + return (-1); + } +#ifdef RLIMIT_NOFILE + if (getrlimit(RLIMIT_NOFILE, &rl) < 0) + return (-1); + if (limit > 0) { + + /* + * MacOSX incorrectly reports rlim_max as RLIM_INFINITY. The true + * hard limit is finite and equals the kern.maxfilesperproc value. + */ +#ifdef USE_MAX_FILES_PER_PROC + int max_files_per_proc; + size_t len = sizeof(max_files_per_proc); + + if (sysctlbyname(MAX_FILES_PER_PROC, &max_files_per_proc, &len, + (void *) 0, (size_t) 0) < 0) + return (-1); + if (limit > max_files_per_proc) + limit = max_files_per_proc; +#endif + if (limit > rl.rlim_max) + rl.rlim_cur = rl.rlim_max; + else + rl.rlim_cur = limit; + if (setrlimit(RLIMIT_NOFILE, &rl) < 0) + return (-1); + } + return (rl.rlim_cur); +#endif + +#ifndef RLIMIT_NOFILE + return (getdtablesize()); +#endif +} + |