From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id 6003C2D13 for ; Tue, 16 Jan 2018 10:01:29 +0100 (CET) Received: from lfbn-lil-1-110-231.w90-45.abo.wanadoo.fr ([90.45.197.231] helo=droids-corp.org) by mail.droids-corp.org with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1ebN7W-00080X-To; Tue, 16 Jan 2018 10:01:28 +0100 Received: by droids-corp.org (sSMTP sendmail emulation); Tue, 16 Jan 2018 10:01:22 +0100 Date: Tue, 16 Jan 2018 10:01:22 +0100 From: Olivier Matz To: Xiao Wang Cc: yliu@fridaylinux.org, thomas@monjalon.net, tiwei.bie@intel.com, dev@dpdk.org, stephen@networkplumber.org, maxime.coquelin@redhat.com Message-ID: <20180116090122.fsvqrgzu5rjqcgre@platinum> References: <20180109160918.29173-4-xiao.w.wang@intel.com> <20180110012356.57456-1-xiao.w.wang@intel.com> <20180110012356.57456-4-xiao.w.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180110012356.57456-4-xiao.w.wang@intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Subject: Re: [dpdk-dev] [PATCH v10 3/5] net: add a helper for making RARP packet 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: Tue, 16 Jan 2018 09:01:29 -0000 Hi Xiao, Please find few comments below. On Wed, Jan 10, 2018 at 09:23:54AM +0800, Xiao Wang wrote: > Suggested-by: Maxime Coquelin > Signed-off-by: Xiao Wang > Reviewed-by: Maxime Coquelin > --- > lib/librte_net/Makefile | 1 + > lib/librte_net/rte_arp.c | 42 ++++++++++++++++++++++++++++++++++++++ > lib/librte_net/rte_arp.h | 17 +++++++++++++++ > lib/librte_net/rte_net_version.map | 6 ++++++ > 4 files changed, 66 insertions(+) > create mode 100644 lib/librte_net/rte_arp.c > > diff --git a/lib/librte_net/Makefile b/lib/librte_net/Makefile > index 5e8a76b68..ab290c382 100644 > --- a/lib/librte_net/Makefile > +++ b/lib/librte_net/Makefile > @@ -13,6 +13,7 @@ LIBABIVER := 1 > > SRCS-$(CONFIG_RTE_LIBRTE_NET) := rte_net.c > SRCS-$(CONFIG_RTE_LIBRTE_NET) += rte_net_crc.c > +SRCS-$(CONFIG_RTE_LIBRTE_NET) += rte_arp.c > > # install includes > SYMLINK-$(CONFIG_RTE_LIBRTE_NET)-include := rte_ip.h rte_tcp.h rte_udp.h rte_esp.h > diff --git a/lib/librte_net/rte_arp.c b/lib/librte_net/rte_arp.c > new file mode 100644 > index 000000000..d7223b044 > --- /dev/null > +++ b/lib/librte_net/rte_arp.c > @@ -0,0 +1,42 @@ > +/* SPDX-License-Identifier: BSD-3-Clause > + * Copyright(c) 2018 Intel Corporation > + */ > + > +#include > + > +#include > + > +#define RARP_PKT_SIZE 64 > +int > +rte_net_make_rarp_packet(struct rte_mbuf *mbuf, const struct ether_addr *mac) > +{ > + struct ether_hdr *eth_hdr; > + struct arp_hdr *rarp; > + > + if (mbuf->buf_len < RARP_PKT_SIZE) > + return -1; > + > + /* Ethernet header. */ > + eth_hdr = rte_pktmbuf_mtod(mbuf, struct ether_hdr *); > + memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN); > + ether_addr_copy(mac, ð_hdr->s_addr); > + eth_hdr->ether_type = htons(ETHER_TYPE_RARP); > + > + /* RARP header. */ > + rarp = (struct arp_hdr *)(eth_hdr + 1); > + rarp->arp_hrd = htons(ARP_HRD_ETHER); > + rarp->arp_pro = htons(ETHER_TYPE_IPv4); > + rarp->arp_hln = ETHER_ADDR_LEN; > + rarp->arp_pln = 4; > + rarp->arp_op = htons(ARP_OP_REVREQUEST); > + > + ether_addr_copy(mac, &rarp->arp_data.arp_sha); > + ether_addr_copy(mac, &rarp->arp_data.arp_tha); > + memset(&rarp->arp_data.arp_sip, 0x00, 4); > + memset(&rarp->arp_data.arp_tip, 0x00, 4); > + > + mbuf->data_len = RARP_PKT_SIZE; > + mbuf->pkt_len = RARP_PKT_SIZE; > + > + return 0; > +} You don't check that there is enough tailroom to write the packet data. Also, nothing verifies that the mbuf passed to the function is empty. I suggest to do the allocation in this function, what do you think? You can also use rte_pktmbuf_append() to check for the tailroom and update data_len/pkt_len: m = rte_pktmbuf_alloc(); if (m == NULL) return NULL; eth_hdr = rte_pktmbuf_append(m, RARP_PKT_SIZE); if (eth_hdr == NULL) { m_freem(m); return NULL; } eth_hdr->... = ...; ... rarp = (struct arp_hdr *)(eth_hdr + 1); rarp->... = ...; ... return m;