Reference

cap_syslog(3)

library for syslog in capability mode

Part of cap_closelog(3).

NAME

cap_syslog, cap_vsyslog, cap_openlog, cap_closelog, cap_setlogmask – library for syslog in capability mode

LIBRARY

library “libcap_syslog”

SYNOPSIS

#include <libcasper.h>

#include <casper/cap_syslog.h>

void

cap_syslog(cap_channel_t *chan, int pri, const char *fmt, ...);

void

cap_vsyslog(cap_channel_t *chan, int priority, const char *fmt, va_list ap);

void

cap_openlog(cap_channel_t *chan, const char *ident, int logopt, int facility);

void

cap_closelog(cap_channel_t *chan);

int

cap_setlogmask(cap_channel_t *chan, int maskpri);

DESCRIPTION

The functions cap_syslog() cap_vsyslog() cap_openlog() cap_closelog() cap_setlogmask() are respectively equivalent to syslog(3), vsyslog(3), openlog(3), closelog(3), setlogmask(3) except that the connection to the system.syslog service needs to be provided.

All of these functions are reentrant but not thread-safe. That is, they may be called from separate threads only with different cap_channel_t arguments or with synchronization.

EXAMPLES

The following example first opens a capability to casper and then uses this capability to create the system.syslog casper service to log messages.

cap_channel_t *capcas, *capsyslog;
/* Open capability to Casper. */
capcas = cap_init();
if (capcas == NULL)
	err(1, "Unable to contact Casper");
/* Enter capability mode sandbox. */
if (cap_enter() < 0 && errno != ENOSYS)
	err(1, "Unable to enter capability mode");
/* Use Casper capability to create capability to the system.syslog service. */
capsyslog = cap_service_open(capcas, "system.syslog");
if (capsyslog == NULL)
	err(1, "Unable to open system.syslog service");
/* Close Casper capability, we don't need it anymore. */
cap_close(capcas);
/* Let's log something. */
cap_syslog(capsyslog, LOG_NOTICE, "System logs from capability mode.");

SEE ALSO

cap_enter(2), closelog(3), err(3), openlog(3), setlogmask(3), syslog(3), vsyslog(3), capsicum(4), nv(9)

HISTORY

The cap_syslog service first appeared in FreeBSD 10.3.

AUTHORS

Mariusz Zaborski ⟨[email protected]⟩

History