From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f195.google.com (mail-pf1-f195.google.com [209.85.210.195]) by dpdk.org (Postfix) with ESMTP id 43E281BAB5 for ; Fri, 11 Jan 2019 19:07:13 +0100 (CET) Received: by mail-pf1-f195.google.com with SMTP id c73so7283027pfe.13 for ; Fri, 11 Jan 2019 10:07:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iYercn/9dovQc4ZsrI8Aq+pLR0u7zsthimC3WBnn2XQ=; b=vOeJUiZeHgu+LKI9dhHdDRVRzVS5W9DnZiUVr0uw/c6jdgtdW+BZCK2fZez6c6AJxb BKrNFeOepKBxhs+taaT7z3KZjqHobP46LCpdcDPfmlaQ06GD9o/o/ky9E06mxJtW3Yle nmNMhvdIIT/2xgjt0n6T0jWxO+ZAZ4f1CpH8UVjVbio6khbjRK/2Aw73SrnWCIZeFNW9 g/o2WbC1A/4mF7de1ISFA7SPkNJsNpQxcEBqZ+4uyfBgE0Nm2LUZmYNbpmj4fa9s5CVa 2Wh2RZ20jlmlSc14CsCOPZzTv+pc90RLiPnKHPnFKlKLORw5C8ICTeEigBbsXnSVBdrE jm7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=iYercn/9dovQc4ZsrI8Aq+pLR0u7zsthimC3WBnn2XQ=; b=LfsVSfLkfpagdDFtSZyUM3Nojey4fnDMzk6LnTAILCvFVLHhPUBknQzCd5vV1vQzm4 p5OxwP8lIsNLODL18QLUZzQRDpP4Jsdafq1jltoZ3QW9BhlIvf95dW/2t2Wrb0rPPdn2 Ba/94goc4KvdFMGMENhkpf6IzUQCoHBfw6N57K9cD8Ie+q46jeOv2THUHUust9MakZMZ TVqPSp6qxJ9CTc5UXUOQbr7AlMs1cPZAlFYNGkM4teWIbA3avpd6sAxkc5neRH2PJbjq mq8FdgjW9gPi4gAj/2nI/Z/bVspNSDfeOmtmPQzSwEW9BeuFH7a+P8Dsml+5iBJG8eLu 5+8A== X-Gm-Message-State: AJcUukdG/BMmvxFFYIlIW+j9XtC6CrjdJJhJhKj52XGXeqErNkUMe1pS 5u3i7gzHvJwzxOiQbAg/1OkWVhilKlI= X-Google-Smtp-Source: ALg8bN4w8kg+QT6XqfBnLTz+YNaWT/U82HWCXO9HmJEG5TN01TynsY/u0HKBrSVXEPmwyNM8EhPJ9Q== X-Received: by 2002:a65:520a:: with SMTP id o10mr14684791pgp.276.1547230032093; Fri, 11 Jan 2019 10:07:12 -0800 (PST) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id n186sm107213303pfn.137.2019.01.11.10.07.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 11 Jan 2019 10:07:11 -0800 (PST) From: Stephen Hemminger To: dev@dpdk.org Cc: Stephen Hemminger , hfli@netitest.com Date: Fri, 11 Jan 2019 10:06:58 -0800 Message-Id: <20190111180659.5972-6-stephen@networkplumber.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111180659.5972-1-stephen@networkplumber.org> References: <20190111180659.5972-1-stephen@networkplumber.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH 5/6] net/tap: let kernel choose tun device name X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Jan 2019 18:07:13 -0000 Assigning tun and tap index in DPDK tap device driver is racy and fails if used with primary/secondary process model. Instead, use the kernel feature of device wildcarding where if a name with %d is used the kernel will fill in the next available device. Reported-by: hfli@netitest.com Fixes: 02f96a0a82d1 ("net/tap: add TUN/TAP device PMD") Signed-off-by: Stephen Hemminger --- drivers/net/tap/rte_eth_tap.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c index 50d6729cb609..b836c1ae3d4e 100644 --- a/drivers/net/tap/rte_eth_tap.c +++ b/drivers/net/tap/rte_eth_tap.c @@ -79,9 +79,6 @@ static const char *valid_arguments[] = { NULL }; -static unsigned int tap_unit; -static unsigned int tun_unit; - static char tuntap_name[8]; static volatile uint32_t tap_trigger; /* Rx trigger */ @@ -151,8 +148,6 @@ tun_alloc(struct pmd_internals *pmd, int is_keepalive) IFF_TAP : IFF_TUN | IFF_POINTOPOINT; strlcpy(ifr.ifr_name, pmd->name, IFNAMSIZ); - TAP_LOG(DEBUG, "ifr_name '%s'", ifr.ifr_name); - fd = open(TUN_TAP_DEV_PATH, O_RDWR); if (fd < 0) { TAP_LOG(ERR, "Unable to create %s interface", tuntap_name); @@ -186,6 +181,13 @@ tun_alloc(struct pmd_internals *pmd, int is_keepalive) goto error; } + /* + * Name passed to kernel might be wildcard like dtun%d + * and need to find the resulting device. + */ + TAP_LOG(DEBUG, "Device name is '%s'", ifr.ifr_name); + strlcpy(pmd->name, ifr.ifr_name, RTE_ETH_NAME_MAX_LEN); + if (is_keepalive) { /* * Detach the TUN/TAP keep-alive queue @@ -1756,6 +1758,7 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name, TAP_LOG(ERR, "Unable to create %s interface", tuntap_name); goto error_exit; } + TAP_LOG(INFO, "allocated %s", pmd->name); ifr.ifr_mtu = dev->data->mtu; if (tap_ioctl(pmd, SIOCSIFMTU, &ifr, 1, LOCAL_AND_REMOTE) < 0) @@ -1917,8 +1920,8 @@ set_interface_name(const char *key __rte_unused, } strlcpy(name, value, RTE_ETH_NAME_MAX_LEN); } else { - snprintf(name, RTE_ETH_NAME_MAX_LEN, "%s%d", - DEFAULT_TAP_NAME, tun_unit - 1); + snprintf(name, RTE_ETH_NAME_MAX_LEN, "%s%%d", + DEFAULT_TAP_NAME); } return 0; } @@ -2031,8 +2034,8 @@ rte_pmd_tun_probe(struct rte_vdev_device *dev) return 0; } - snprintf(tun_name, sizeof(tun_name), "%s%u", - DEFAULT_TUN_NAME, tun_unit++); + snprintf(tun_name, sizeof(tun_name), "%s%%d", + DEFAULT_TUN_NAME); if (params && (params[0] != '\0')) { TAP_LOG(DEBUG, "parameters (%s)", params); @@ -2052,17 +2055,15 @@ rte_pmd_tun_probe(struct rte_vdev_device *dev) } pmd_link.link_speed = ETH_SPEED_NUM_10G; - TAP_LOG(DEBUG, "Initializing pmd_tun for %s as %s", - name, tun_name); + TAP_LOG(DEBUG, "Initializing pmd_tun for %s", name); ret = eth_dev_tap_create(dev, tun_name, remote_iface, 0, - ETH_TUNTAP_TYPE_TUN); + ETH_TUNTAP_TYPE_TUN); leave: if (ret == -1) { TAP_LOG(ERR, "Failed to create pmd for %s as %s", name, tun_name); - tun_unit--; /* Restore the unit number */ } rte_kvargs_free(kvlist); @@ -2218,8 +2219,8 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev) } speed = ETH_SPEED_NUM_10G; - snprintf(tap_name, sizeof(tap_name), "%s%u", - DEFAULT_TAP_NAME, tap_unit++); + snprintf(tap_name, sizeof(tap_name), + "%s%%d", DEFAULT_TAP_NAME); memset(remote_iface, 0, RTE_ETH_NAME_MAX_LEN); if (params && (params[0] != '\0')) { @@ -2282,7 +2283,6 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev) rte_mp_action_unregister(TAP_MP_KEY); tap_devices_count--; } - tap_unit--; /* Restore the unit number */ } rte_kvargs_free(kvlist); -- 2.20.1