From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f5.google.com (mail-pj2-f5.google.com [74.125.227.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6714F3AB292 for ; Thu, 10 Sep 2026 21:19:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789075194; cv=none; b=oo9C4eRNj1iDyWA5pRhk7KHqKZg/yb2WCQyC0Q9/9nfKCrEVe7oTP5EutEI4fKWZRVuaYEqqL9X8Xc82yMKHOU7slbJHvGyRfqhiiJ+zOGOHP9Z+A3s7BZslNagloTkpM/SvuUtak6LCX3oZPDD9RtTKVNwePj61RtU8JAOSGBE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789075194; c=relaxed/simple; bh=0aH1/xZq6BqoJ8NBok0Fya68fVfmA8ZB4sdGtLgyxas=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PvvfnDEe/xbwqyfjXgpVGAu4+9CMmTDf12F+Ues8hQMFpKr5pGxCN/DCE59eG5KoxPF0oUNwqGPolSfB2Qnc9WO8JMLsSDT3KberI9o5SBaPc+B8/B7cuF+NXksk2PuI+MuXrpFhE8TQW/cn6tDEsjNUpq2wAN0OSsRf5Xp9HUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Rowc8lce; arc=none smtp.client-ip=74.125.227.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Rowc8lce" Received: by mail-pj2-f5.google.com with SMTP id 98e67ed59e1d1-3965683e9e9so96622a91.1 for ; Thu, 10 Sep 2026 14:19:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789075182; x=1789679982; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=u1rqc5jPkp4qWs7zOMQ/40kpJI2gBjFB0iGuKAIdw1E=; b=Rowc8lcevd/wERc/j0B+/EZnNBqPzlzXXHuaSQETM0R8azx35V+0fkb7kUe/JkCuI+ aL/uqFD3M8fSe7R0CvlHJO26ZeLp4QPC6ttRcdiwBQ15+ZSORiWVcwoG/pw7PFyh2jtT fOzLf83G6hosKeWYkcYPB/MzTptXgsaQClTNSxwSCVW+lddxHmm72Hfv17LGe0oPWGkc 0u3/Bhhz7HpbFFkq28avgX6psamoxh5e37DQN0BWYcNPRpB85zjLFpNYxxaMcls+6cpK SSkGn4MHP5X2lCY6t1Vcd2/C1IV308Qk2lBnx/Nyehu0tpW5x21gIRcMydUUd+9DPKg1 ST1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789075182; x=1789679982; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=u1rqc5jPkp4qWs7zOMQ/40kpJI2gBjFB0iGuKAIdw1E=; b=gIyaxbY6evqX1kxzUIUlBFyVzHozpBn87g+gjLTBspeELWmDhCxkoIuUMwFqvPjS53 cI8ywMFd4Kj7pwZJa+tAamsTVAQEtM6bbTJ4YF+efGlWjMJSB6MYl76mI8BWUL9ptSV3 FhIKJJAfwbT0QwMRVk+jJDeGz6xrHFNLwTWAoj4SnecWUnT8v4W2IRaTxIlvW6Rvh6qv LhR4tFJyVEXP1zYy1tE8cRKk81tIRvLtg9VNUE+x+W17D2yK1LTThVvL2ZN8l0nkdpeW fFhXstapuFraL1VkglGZKxDkP9Q/vXXxZ5B2UX+xin1vl29Vk67+XmjYdsjCVb/ttjA4 y+sw== X-Gm-Message-State: AFuF++l8h7CHCqDRCuqBuR0YfR+db+sLaws/r+EQOlYXb01ALJolFMHD WwduXhG+34ZByrkvW7xuVGDaZiT4DgK/wX9GtvUcKFu8byMBY+9LNiEn X-Gm-Gg: AYBFou1hF7UO5adPkdPPWqxB+TDVrNZ+YNui/Vc4BP80MyEj05af9j5nrmvtsOOmmOz KepKwJGLE0VAbKNc4VDo+LSWAAKnk60Hslruc1j8FPHoscuQeAkTs19Zg/21w24sGB8NGNcxlvt xWlGlQp+40D4S/3cdKGMsN0gjMJYbQ7yexJEcUQ9CnEnBTCvozZTwlOLXBQqvHK1URknmTvWvhr u5y8qo/wlypUSNzPwMwcP9+BpYgqRuXJgeGcqc6eusUSCdHPoiT/o7rwiq5EDUEXkLaUrEH1UgQ gT0gQaslY4319YbHHCqI9RCfykULvyYUrcgBDW198PrcmtJi36I7AKyA8+/mEtLGaaeUb9PaP+o Q0Pyf7E/5M4vIUio4AM1pn5A3aQfJqJS156/Thp8u/CG+y03cjwKlmIGroK2PVec4o1aAM3OMZP fKeV19ZEgu0DUQC/bKIEsfksgXuhjd0pEll2jLINjyLTgeaB7w6m6m2k7wZ0bQvwKN X-Received: by 2002:a05:6a00:4fc9:b0:846:bc60:5bf7 with SMTP id d2e1a72fcca58-86b31401661mr1235255b3a.6.1789075181652; Thu, 10 Sep 2026 14:19:41 -0700 (PDT) Received: from localhost ([2a03:2880:2ff:47::]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-86b29cbb760sm146528b3a.46.2026.09.10.14.19.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Sep 2026 14:19:41 -0700 (PDT) Date: Thu, 10 Sep 2026 14:19:35 -0700 From: Stanislav Fomichev To: Fernando Fernandez Mancera Cc: netdev@vger.kernel.org, horms@kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, davem@davemloft.net, David Ahern , Ido Schimmel , Willem de Bruijn , Kees Cook , Kuniyuki Iwashima , Richard Gobert , Marc Kleine-Budde , Jeff Layton , Qi Tang , linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/13 net-next] net: inet: relocate ip_generic_getfrag and guard IPv4 socket logic Message-ID: References: <20260910144914.8025-1-fmancera@suse.de> <20260910144914.8025-4-fmancera@suse.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260910144914.8025-4-fmancera@suse.de> On 09/10, Fernando Fernandez Mancera wrote: > To enable compiling the INET subsystem without IPv4, shared generic > utilities must be relocated and IPv4 socket logic must be guarded for > CONFIG_IPV4. > > This patch moves the generic ip_generec_getfrag() from ip_output.c to > af_inet.c. It also introduces CONFIG_IPV4 guards around af_inet.c to > reject IPv4-specific ioctls, protocol registrations and bind requests. > The same guard is added to reject IPv4-mapped IPv6. > > Signed-off-by: Fernando Fernandez Mancera > --- > net/ipv4/af_inet.c | 96 +++++++++++++++++++++++++++++++++++++------- > net/ipv4/ip_output.c | 18 --------- > net/ipv6/af_inet6.c | 5 +++ > net/ipv6/datagram.c | 12 ++++++ > 4 files changed, 99 insertions(+), 32 deletions(-) > > diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c > index d9421ac38d78..b0c48ba544bf 100644 > --- a/net/ipv4/af_inet.c > +++ b/net/ipv4/af_inet.c > @@ -129,6 +129,28 @@ > int disable_ipv6_mod; > EXPORT_SYMBOL(disable_ipv6_mod); > > +/* Keep the function here for now as it is generic, it should be moved > + * to a common L3 place > + */ > +int > +ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) > +{ > + struct msghdr *msg = from; > + > + if (skb->ip_summed == CHECKSUM_PARTIAL) { > + if (!copy_from_iter_full(to, len, &msg->msg_iter)) > + return -EFAULT; > + } else { > + __wsum csum = 0; > + > + if (!csum_and_copy_from_iter_full(to, len, &csum, &msg->msg_iter)) > + return -EFAULT; > + skb->csum = csum_block_add(skb->csum, csum, odd); > + } > + return 0; > +} > +EXPORT_SYMBOL(ip_generic_getfrag); > + > /* The inetsw table contains everything that inet_create needs to > * build a new socket. > */ > @@ -425,8 +447,10 @@ int inet_release(struct socket *sock) > if (!sk->sk_kern_sock) > BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk); > > +#if IS_ENABLED(CONFIG_IPV4) > /* Applications forget to leave groups before exiting */ > ip_mc_drop_socket(sk); > +#endif > > /* If linger is set, we don't return until the close > * is complete. Otherwise we return immediately. The > @@ -478,6 +502,7 @@ EXPORT_SYMBOL(inet_bind); > int __inet_bind(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len, > u32 flags) > { > +#if IS_ENABLED(CONFIG_IPV4) > struct sockaddr_in *addr = (struct sockaddr_in *)uaddr; > struct inet_sock *inet = inet_sk(sk); > struct net *net = sock_net(sk); > @@ -570,6 +595,9 @@ int __inet_bind(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len, > release_sock(sk); > out: > return err; > +#else > + return -EAFNOSUPPORT; > +#endif > } > > int inet_dgram_connect(struct socket *sock, struct sockaddr_unsized *uaddr, > @@ -962,18 +990,24 @@ EXPORT_SYMBOL(inet_shutdown); > int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) > { > struct sock *sk = sock->sk; > - int err = 0; > - struct net *net = sock_net(sk); > +#if IS_ENABLED(CONFIG_IPV4) > void __user *p = (void __user *)arg; > - struct ifreq ifr; > + struct net *net = sock_net(sk); > struct rtentry rt; > + struct ifreq ifr; > +#endif > + int err = 0; > > switch (cmd) { > case SIOCADDRT: > case SIOCDELRT: > +#if IS_ENABLED(CONFIG_IPV4) > if (copy_from_user(&rt, p, sizeof(struct rtentry))) > return -EFAULT; > err = ip_rt_ioctl(net, cmd, &rt); > +#else > + err = -EOPNOTSUPP; > +#endif > break; > case SIOCRTMSG: > err = -EINVAL; > @@ -981,18 +1015,26 @@ int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) > case SIOCDARP: > case SIOCGARP: > case SIOCSARP: > +#if IS_ENABLED(CONFIG_IPV4) > err = arp_ioctl(net, cmd, (void __user *)arg); > +#else > + err = -EOPNOTSUPP; > +#endif > break; > case SIOCGIFADDR: > case SIOCGIFBRDADDR: > case SIOCGIFNETMASK: > case SIOCGIFDSTADDR: > case SIOCGIFPFLAGS: > +#if IS_ENABLED(CONFIG_IPV4) > if (get_user_ifreq(&ifr, NULL, p)) > return -EFAULT; > err = devinet_ioctl(net, cmd, &ifr); > if (!err && put_user_ifreq(&ifr, p)) > err = -EFAULT; > +#else > + err = -EOPNOTSUPP; > +#endif > break; > > case SIOCSIFADDR: > @@ -1001,9 +1043,13 @@ int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) > case SIOCSIFDSTADDR: > case SIOCSIFPFLAGS: > case SIOCSIFFLAGS: > +#if IS_ENABLED(CONFIG_IPV4) > if (get_user_ifreq(&ifr, NULL, p)) > return -EFAULT; > err = devinet_ioctl(net, cmd, &ifr); > +#else > + err = -EOPNOTSUPP; > +#endif (passing by comment) Don't we have a coding style rule to avoid ifdef conditional in C code? Should we add some new devinet4_ioctl/etc wrappers that we can conditionally compile out in the headers?