From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 83E4F5A0274 for ; Fri, 3 Nov 2023 03:23:13 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=201602; t=1698978187; bh=Prn7WPAdUEbCRonzWULzL/8J/ad95/c6SffcIM7gpgY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BYgTZnpN8b3m9mH4yr3Ob/uP+2Nv+Gr9FIpfPHS9Bw2rWclVaGdngDJ+nww8T8vwl sGMDpaxNprZd4faLNY2L8Aec7f0i9Dh+7ILpIwy6SmlSabzgIBe9tVm4chi1gHkIPG h1y7Kr5a8owgIBEIcHv3fH/ce+OJ+5m4x88GnMw4= Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4SM4KR5p46z4xVV; Fri, 3 Nov 2023 13:23:07 +1100 (AEDT) From: David Gibson To: passt-dev@passt.top, Stefano Brivio Subject: [PATCH v2 4/9] util: Add open_in_ns() helper Date: Fri, 3 Nov 2023 13:22:58 +1100 Message-ID: <20231103022303.968638-5-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231103022303.968638-1-david@gibson.dropbear.id.au> References: <20231103022303.968638-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: TWKVTH5JKDBEOCGRNDF6LKI7UQZW25EF X-Message-ID-Hash: TWKVTH5JKDBEOCGRNDF6LKI7UQZW25EF X-MailFrom: dgibson@gandalf.ozlabs.org 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: David Gibson 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: Most of our helpers which need to enter the pasta network namespace are quite specialised. Add one which is rather general - it just open()s a given file in the namespace context and returns the fd back to the main namespace. This will have some future uses. Signed-off-by: David Gibson --- util.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ util.h | 1 + 2 files changed, 54 insertions(+) diff --git a/util.c b/util.c index a8f3b35..c38ab7e 100644 --- a/util.c +++ b/util.c @@ -364,6 +364,59 @@ bool ns_is_init(void) return ret; } +/** + * struct open_in_ns_args - Parameters for do_open_in_ns() + * @c: Execution context + * @fd: Filled in with return value from open() + * @err: Filled in with errno if open() failed + * @path: Path to open + * @flags: open() flags + */ +struct open_in_ns_args { + const struct ctx *c; + int fd; + int err; + const char *path; + int flags; +}; + +/** + * do_open_in_ns() - Enter namespace and open a file + * @arg: See struct open_in_ns_args + * + * Must be called via NS_CALL() + */ +static int do_open_in_ns(void *arg) +{ + struct open_in_ns_args *a = (struct open_in_ns_args *)arg; + + ns_enter(a->c); + + a->fd = open(a->path, a->flags); + a->err = errno; + + return 0; +} + +/** + * open_in_ns() - open() within the pasta namespace + * @c: Execution context + * @path: Path to open + * @flags: open() flags + * + * Return: fd of open()ed file or -1 on error, errno is set to indicate error + */ +int open_in_ns(const struct ctx *c, const char *path, int flags) +{ + struct open_in_ns_args arg = { + .c = c, .path = path, .flags = flags, + }; + + NS_CALL(do_open_in_ns, &arg); + errno = arg.err; + return arg.fd; +} + /** * pid_file() - Write PID to file, if requested to do so, and close it * @fd: Open PID file descriptor, closed on exit, -1 to skip writing it diff --git a/util.h b/util.h index 9effc54..78a8fb2 100644 --- a/util.h +++ b/util.h @@ -219,6 +219,7 @@ int bitmap_isset(const uint8_t *map, int bit); char *line_read(char *buf, size_t len, int fd); void ns_enter(const struct ctx *c); bool ns_is_init(void); +int open_in_ns(const struct ctx *c, const char *path, int flags); void write_pidfile(int fd, pid_t pid); int __daemon(int pidfile_fd, int devnull_fd); int fls(unsigned long x); -- 2.41.0