Manual Pages  — CAP_SYSLOG

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

LIBRARY SYNOPSIS DESCRIPTION EXAMPLES SEE ALSO HISTORY AUTHORS

libcap_syslog

#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);

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.");

The cap_syslog service first appeared in FreeBSD 10.3 .

Mariusz Zaborski <Mt oshogbo@FreeBSD.org>