core/logging: Fix broken syslog levels on older glibc.

The fix to ASTERISK-25407 introduced the usage of LOG_MAKEPRI. However
this macro is broken in older glibc (< 2.17); it would left-shift the
facility a second time, causing the resultant priority to become
invalid.

The syslog manpage mentions nothing about LOG_MAKEPRI and suggests this:

    The priority argument is formed by ORing the facility and the level
    values [...].

ASTERISK-25510 #close
Reported by: Michael Newton

Change-Id: Ia89debe7fac5ad090c7ef595c0707f31bb1e3d03

diff --git a/main/logger.c b/main/logger.c
index 13f6de89026f3c7d13e05ee063fbd4a78826f890..42a1c700049cd9946001f1c6c74519d344c4ab47 100644 (file)
--- a/main/logger.c
+++ b/main/logger.c
@@ -1514,7 +1514,8 @@ static void logger_print_normal(struct logmsg *logmsg)
                                                continue;
                                        }
 
-                                       syslog_level = LOG_MAKEPRI(chan->facility, syslog_level);
+                                       /* Don't use LOG_MAKEPRI because it's broken in glibc<2.17 */
+                                       syslog_level = chan->facility | syslog_level; /* LOG_MAKEPRI(chan->facility, syslog_level); */
                                        if (!chan->formatter.format_log(chan, logmsg, buf, BUFSIZ)) {
                                                syslog(syslog_level, "%s", buf);
                                        }