From: Paul Holzinger <pholzing@redhat.com>
To: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [PATCH] passt, log: Call __openlog() earlier, log to stderr until we detach
Date: Wed, 13 Mar 2024 11:23:56 +0100 [thread overview]
Message-ID: <4ea9d22c-fed4-410b-84f9-340f95c63c9b@redhat.com> (raw)
In-Reply-To: <20240312223448.649997-1-sbrivio@redhat.com>
Thanks for the quick patch.
On 12/03/2024 23:34, Stefano Brivio wrote:
> Paul reports that, with commit 15001b39ef1d ("conf: set the log level
> much earlier"), early messages aren't reported to standard error
> anymore.
>
> The reason is that, once the log mask is changed from LOG_EARLY, we
> don't force logging to stderr, and this mechanism was abused to have
> early errors on stderr. Now that we drop LOG_EARLY earlier on, this
> doesn't work anymore.
>
> Call __openlog() as soon as we know the mode we're running as, using
> LOG_PERROR. Then, once we detach, if we're not running from an
> interactive terminal and logging to standard error is not forced,
> drop LOG_PERROR from the options.
>
> While at it, make sure we don't print messages to standard error
> reporting that we couldn't log to the system logger, if we didn't
> open a connection yet. That's expected.
>
> Reported-by: Paul Holzinger <pholzing@redhat.com>
> Fixes: 15001b39ef1d ("conf: set the log level much earlier")
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Tested-by: Paul Holzinger <pholzing@redhat.com>
> ---
> log.c | 2 +-
> passt.c | 14 +++++++-------
> 2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/log.c b/log.c
> index eafaca2..bdd31b4 100644
> --- a/log.c
> +++ b/log.c
> @@ -174,7 +174,7 @@ void passt_vsyslog(int pri, const char *format, va_list ap)
> if (log_opt & LOG_PERROR)
> fprintf(stderr, "%s", buf + prefix_len);
>
> - if (send(log_sock, buf, n, 0) != n)
> + if (log_sock >= 0 && send(log_sock, buf, n, 0) != n)
> fprintf(stderr, "Failed to send %i bytes to syslog\n", n);
> }
>
> diff --git a/passt.c b/passt.c
> index f430648..e4cb11e 100644
> --- a/passt.c
> +++ b/passt.c
> @@ -225,6 +225,8 @@ int main(int argc, char **argv)
> strncpy(argv0, argv[0], PATH_MAX - 1);
> name = basename(argv0);
> if (strstr(name, "pasta")) {
> + __openlog(log_name = "pasta", LOG_PERROR, LOG_DAEMON);
> +
> sa.sa_handler = pasta_child_handler;
> if (sigaction(SIGCHLD, &sa, NULL)) {
> die("Couldn't install signal handlers: %s",
> @@ -237,18 +239,16 @@ int main(int argc, char **argv)
> }
>
> c.mode = MODE_PASTA;
> - log_name = "pasta";
> } else if (strstr(name, "passt")) {
> + __openlog(log_name = "passt", LOG_PERROR, LOG_DAEMON);
> +
> c.mode = MODE_PASST;
> - log_name = "passt";
> } else {
> exit(EXIT_FAILURE);
> }
>
> madvise(pkt_buf, TAP_BUF_BYTES, MADV_HUGEPAGE);
>
> - __openlog(log_name, 0, LOG_DAEMON);
> -
> c.epollfd = epoll_create1(EPOLL_CLOEXEC);
> if (c.epollfd == -1) {
> perror("epoll_create1");
> @@ -269,9 +269,6 @@ int main(int argc, char **argv)
> conf(&c, argc, argv);
> trace_init(c.trace);
>
> - if (c.force_stderr || isatty(fileno(stdout)))
> - __openlog(log_name, LOG_PERROR, LOG_DAEMON);
> -
> pasta_netns_quit_init(&c);
>
> tap_sock_init(&c);
> @@ -314,6 +311,9 @@ int main(int argc, char **argv)
> if (isolate_prefork(&c))
> die("Failed to sandbox process, exiting");
>
> + if (!c.force_stderr && !isatty(fileno(stdout)))
I still have the feeling this should check the stderr fd instead of
stdout as it is logging to stderr. But I guess it shouldn't make a big
difference in real situations so not a big deal.
> + __openlog(log_name, 0, LOG_DAEMON);
> +
> if (!c.foreground)
> __daemon(pidfile_fd, devnull_fd);
> else
next prev parent reply other threads:[~2024-03-13 10:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-12 22:34 [PATCH] passt, log: Call __openlog() earlier, log to stderr until we detach Stefano Brivio
2024-03-13 10:23 ` Paul Holzinger [this message]
2024-03-13 10:41 ` Stefano Brivio
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