From patchwork Mon Feb 13 08:44:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 13137941 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AC5D3C636CC for ; Mon, 13 Feb 2023 08:44:37 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.494207.764207 (Exim 4.92) (envelope-from ) id 1pRURj-0005Kp-24; Mon, 13 Feb 2023 08:44:23 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 494207.764207; Mon, 13 Feb 2023 08:44:23 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pRURi-0005Kg-UG; Mon, 13 Feb 2023 08:44:22 +0000 Received: by outflank-mailman (input) for mailman id 494207; Mon, 13 Feb 2023 08:44:22 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1pRURi-00053b-8Y for xen-devel@lists.xenproject.org; Mon, 13 Feb 2023 08:44:22 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 9bda6e54-ab7a-11ed-933c-83870f6b2ba8; Mon, 13 Feb 2023 09:44:20 +0100 (CET) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 95DCF67B09; Mon, 13 Feb 2023 08:44:21 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 6D2A21391B; Mon, 13 Feb 2023 08:44:21 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id VAl9GWX46WMuRAAAMHmgww (envelope-from ); Mon, 13 Feb 2023 08:44:21 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 9bda6e54-ab7a-11ed-933c-83870f6b2ba8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1676277861; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U4WUHNcXaKUs5EWJgyYOwx2UyA3oTZifWWQZCeAXA8E=; b=r91MzCy85Iz1/IfPwuNm+gVo6sS8uA04Tq51j4D7DN/0uBFeYTGxHmfLk5yiywCZbf8d6T udqXCa918VMQ+NMjKC7jCIr1fSLuylUAGZkkgITcfp8L0vXHP6QalG4N/BOyWNkewUwjCA eZVNhUqOzaW/mjJ2D+Bx2trwCwEyO4k= From: Juergen Gross To: minios-devel@lists.xenproject.org, xen-devel@lists.xenproject.org Cc: samuel.thibault@ens-lyon.org, wl@xen.org, Juergen Gross Subject: [PATCH v3 1/7] Mini-OS: xenbus: add support for reading node from directory Date: Mon, 13 Feb 2023 09:44:06 +0100 Message-Id: <20230213084412.21065-2-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230213084412.21065-1-jgross@suse.com> References: <20230213084412.21065-1-jgross@suse.com> MIME-Version: 1.0 Especially PV device drivers often need to read multiple Xenstore nodes from a common directory. Add support for reading a string or an unsigned value by specifying the directory and the node. Signed-off-by: Juergen Gross Reviewed-by: Samuel Thibault --- V2: - check sscanf() return value (Samuel Thibault) --- include/xenbus.h | 6 ++++++ xenbus.c | 40 +++++++++++++++++++++++++++++++++++++--- 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/include/xenbus.h b/include/xenbus.h index 3871f358..c0fc0ac5 100644 --- a/include/xenbus.h +++ b/include/xenbus.h @@ -108,6 +108,12 @@ int xenbus_read_integer(const char *path); * read and parsing were successful, 0 if not */ int xenbus_read_uuid(const char* path, unsigned char uuid[16]); +/* Support functions for reading values from directory/node tuple. */ +char *xenbus_read_string(xenbus_transaction_t xbt, const char *dir, + const char *node, char **value); +char *xenbus_read_unsigned(xenbus_transaction_t xbt, const char *dir, + const char *node, unsigned int *value); + /* Contraction of snprintf and xenbus_write(path/node). */ char* xenbus_printf(xenbus_transaction_t xbt, const char* node, const char* path, diff --git a/xenbus.c b/xenbus.c index 81e9b65d..923e8181 100644 --- a/xenbus.c +++ b/xenbus.c @@ -936,16 +936,21 @@ int xenbus_read_uuid(const char *path, unsigned char uuid[16]) return 1; } +#define BUFFER_SIZE 256 +static void xenbus_build_path(const char *dir, const char *node, char *res) +{ + BUG_ON(strlen(dir) + strlen(node) + 1 >= BUFFER_SIZE); + sprintf(res,"%s/%s", dir, node); +} + char *xenbus_printf(xenbus_transaction_t xbt, const char* node, const char* path, const char* fmt, ...) { -#define BUFFER_SIZE 256 char fullpath[BUFFER_SIZE]; char val[BUFFER_SIZE]; va_list args; - BUG_ON(strlen(node) + strlen(path) + 1 >= BUFFER_SIZE); - sprintf(fullpath,"%s/%s", node, path); + xenbus_build_path(node, path, fullpath); va_start(args, fmt); vsprintf(val, fmt, args); va_end(args); @@ -964,6 +969,35 @@ domid_t xenbus_get_self_id(void) return ret; } +char *xenbus_read_string(xenbus_transaction_t xbt, const char *dir, + const char *node, char **value) +{ + char path[BUFFER_SIZE]; + + xenbus_build_path(dir, node, path); + + return xenbus_read(xbt, path, value); +} + +char *xenbus_read_unsigned(xenbus_transaction_t xbt, const char *dir, + const char *node, unsigned int *value) +{ + char path[BUFFER_SIZE]; + char *msg; + char *str; + + xenbus_build_path(dir, node, path); + msg = xenbus_read(xbt, path, &str); + if ( msg ) + return msg; + + if ( sscanf(str, "%u", value) != 1 ) + msg = strdup("EINVAL"); + free(str); + + return msg; +} + /* * Local variables: * mode: C