From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by passt.top (Postfix, from userid 1000) id 0568B5A0283; Mon, 22 May 2023 19:46:08 +0200 (CEST) From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH v3 02/10] pasta: Improve error handling on failure to join network namespace Date: Mon, 22 May 2023 19:45:59 +0200 Message-Id: <20230522174607.2824220-3-sbrivio@redhat.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230522174607.2824220-1-sbrivio@redhat.com> References: <20230522174607.2824220-1-sbrivio@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: RF3EBS233TXBNRDF6KOATGLM6GMEUVMW X-Message-ID-Hash: RF3EBS233TXBNRDF6KOATGLM6GMEUVMW X-MailFrom: sbrivio@passt.top X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Callum Parsey , me@yawnt.com, David Gibson , lemmi@nerd2nerd.org, Andrea Arcangeli X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: In pasta_wait_for_ns(), open() failing with ENOENT is expected: we're busy-looping until the network namespace appears. But any other failure is not something we're going to recover from: return right away if we don't get either success or ENOENT. Now that pasta_wait_for_ns() can actually fail, handle that in pasta_start_ns() by reporting the issue and exiting. Looping on EPERM, when pasta doesn't actually have the permissions to join a given namespace, isn't exactly a productive thing to do. Signed-off-by: Stefano Brivio Reviewed-by: David Gibson --- pasta.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/pasta.c b/pasta.c index b30ce70..2a6fb60 100644 --- a/pasta.c +++ b/pasta.c @@ -95,8 +95,11 @@ static int pasta_wait_for_ns(void *arg) char ns[PATH_MAX]; snprintf(ns, PATH_MAX, "/proc/%i/ns/net", pasta_child_pid); - do - while ((c->pasta_netns_fd = open(ns, flags)) < 0); + while ((c->pasta_netns_fd = open(ns, flags)) < 0) { + if (errno != ENOENT) + return 0; + } + while (setns(c->pasta_netns_fd, CLONE_NEWNET) && !close(c->pasta_netns_fd)); @@ -257,6 +260,8 @@ void pasta_start_ns(struct ctx *c, uid_t uid, gid_t gid, } NS_CALL(pasta_wait_for_ns, c); + if (c->pasta_netns_fd < 0) + die("Failed to join network namespace"); } /** -- 2.39.2