From 0cf227229bfd288a67fd9d4005ee01ffdb492c70 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 28 Oct 2015 21:40:45 +0100 Subject: linux-user: manage bind with a socket of SOCK_PACKET type. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is obsolete, but if we want to use dhcp with an old distro (like debian etch), we need it. Some users (like dhclient) use SOCK_PACKET with AF_PACKET and the kernel allows that. packet(7) In Linux 2.0, the only way to get a packet socket was by calling socket(AF_INET, SOCK_PACKET, protocol). This is still supported but strongly deprecated. The main difference between the two methods is that SOCK_PACKET uses the old struct sockaddr_pkt to specify an inter‐ face, which doesn't provide physical layer independence. struct sockaddr_pkt { unsigned short spkt_family; unsigned char spkt_device[14]; unsigned short spkt_protocol; }; spkt_family contains the device type, spkt_protocol is the IEEE 802.3 protocol type as defined in and spkt_device is the device name as a null-terminated string, for example, eth0. Signed-off-by: Laurent Vivier Signed-off-by: Riku Voipio --- linux-user/syscall.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'linux-user') diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 3484132..94d64fa 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -2090,6 +2090,30 @@ static int sock_flags_fixup(int fd, int target_type) return fd; } +static abi_long packet_target_to_host_sockaddr(void *host_addr, + abi_ulong target_addr, + socklen_t len) +{ + struct sockaddr *addr = host_addr; + struct target_sockaddr *target_saddr; + + target_saddr = lock_user(VERIFY_READ, target_addr, len, 1); + if (!target_saddr) { + return -TARGET_EFAULT; + } + + memcpy(addr, target_saddr, len); + addr->sa_family = tswap16(target_saddr->sa_family); + /* spkt_protocol is big-endian */ + + unlock_user(target_saddr, target_addr, 0); + return 0; +} + +static TargetFdTrans target_packet_trans = { + .target_to_host_addr = packet_target_to_host_sockaddr, +}; + /* do_socket() Must return target values and target errnos. */ static abi_long do_socket(int domain, int type, int protocol) { @@ -2112,6 +2136,12 @@ static abi_long do_socket(int domain, int type, int protocol) ret = get_errno(socket(domain, type, protocol)); if (ret >= 0) { ret = sock_flags_fixup(ret, target_type); + if (type == SOCK_PACKET) { + /* Manage an obsolete case : + * if socket type is SOCK_PACKET, bind by name + */ + fd_trans_register(ret, &target_packet_trans); + } } return ret; } -- cgit v1.1