From 834b9a30491b0211f59b4e0ac2a79910665f8e0d Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Thu, 23 Feb 2023 18:32:20 +0100 Subject: [PATCH] log: Send identifier string in log messages, openlog() won't work for us openlog() can be used to set "ident" and have all the log messages prefixed by it, but only if we call syslog() -- this is implemented by C libraries. We don't log messages with syslog(), though, as we have a custom implementation to ensure we don't need dynamic memory allocation. This means that it's perfectly useless to call openlog(), and that we have to prefix every message we log by the identifier on our own. Reported-by: Andrea Bolognani Signed-off-by: Stefano Brivio Tested-by: Andrea Bolognani Reviewed-by: Andrea Bolognani Reviewed-by: David Gibson --- log.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/log.c b/log.c index f23e8ef..bfde6ce 100644 --- a/log.c +++ b/log.c @@ -106,7 +106,7 @@ void trace_init(int enable) } /** - * __openlog() - Non-optional openlog() wrapper, to allow custom vsyslog() + * __openlog() - Non-optional openlog() implementation, for custom vsyslog() * @ident: openlog() identity (program name) * @option: openlog() options * @facility: openlog() facility (LOG_DAEMON) @@ -136,8 +136,6 @@ void __openlog(const char *ident, int option, int facility) log_mask |= facility; strncpy(log_ident, ident, sizeof(log_ident) - 1); log_opt = option; - - openlog(ident, option, facility); } /** @@ -158,11 +156,11 @@ void __setlogmask(int mask) */ void passt_vsyslog(int pri, const char *format, va_list ap) { + int prefix_len, n; char buf[BUFSIZ]; - int n; - /* Send without name and timestamp, the system logger should add them */ - n = snprintf(buf, BUFSIZ, "<%i> ", pri); + /* Send without timestamp, the system logger should add it */ + n = prefix_len = snprintf(buf, BUFSIZ, "<%i> %s: ", pri, log_ident); n += vsnprintf(buf + n, BUFSIZ - n, format, ap); @@ -170,7 +168,7 @@ void passt_vsyslog(int pri, const char *format, va_list ap) n += snprintf(buf + n, BUFSIZ - n, "\n"); if (log_opt & LOG_PERROR) - fprintf(stderr, "%s", buf + sizeof("<0>")); + fprintf(stderr, "%s", buf + prefix_len); if (send(log_sock, buf, n, 0) != n) fprintf(stderr, "Failed to send %i bytes to syslog\n", n);