From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by passt.top (Postfix, from userid 1000) id A558E5A0270; Sun, 14 May 2023 20:14:15 +0200 (CEST) From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH 02/10] pasta: Improve error handling on failure to join network namespace Date: Sun, 14 May 2023 20:14:07 +0200 Message-Id: <20230514181415.313420-3-sbrivio@redhat.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230514181415.313420-1-sbrivio@redhat.com> References: <20230514181415.313420-1-sbrivio@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: 4UXV2ABTZUXUORSN4Z6I3RK5Q5H65VVG X-Message-ID-Hash: 4UXV2ABTZUXUORSN4Z6I3RK5Q5H65VVG 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 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 --- pasta.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/pasta.c b/pasta.c index 3a4d704..2fa0168 100644 --- a/pasta.c +++ b/pasta.c @@ -94,8 +94,11 @@ 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)); @@ -252,6 +255,8 @@ 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