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Re: [Qemu-devel] [PATCH v2] linux-user: improve target_to_host_sock_type
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From: |
Petar Jovanovic |
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Subject: |
Re: [Qemu-devel] [PATCH v2] linux-user: improve target_to_host_sock_type conversion |
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Date: |
Tue, 23 Apr 2013 00:15:49 +0000 |
Thanks Aurelien for your comments.
What others think? Can we submit this version of the patch? Riku? Richard, Blue?
Petar
________________________________________
From: Aurelien Jarno address@hidden
Sent: Monday, April 15, 2013 3:47 PM
To: Petar Jovanovic
Cc: address@hidden; Petar Jovanovic; address@hidden; address@hidden;
address@hidden
Subject: Re: [PATCH v2] linux-user: improve target_to_host_sock_type conversion
On Mon, Apr 01, 2013 at 05:49:39PM +0200, Petar Jovanovic wrote:
> From: Petar Jovanovic <address@hidden>
>
> Previous implementation has failed to take into account different value of
> SOCK_NONBLOCK on target and host, and existence of SOCK_CLOEXEC.
> The same conversion has to be applied both for do_socket and do_socketpair,
> so the code has been isolated in a static inline function.
> The change is valid for architectures that define ARCH_HAS_SOCKET_TYPES,
> these are MIPS, SPARC and ALPHA now.
>
> enum sock_type in linux-user/socket.h has been extended to include
> TARGET_SOCK_CLOEXEC and TARGET_SOCK_NONBLOCK, similar to definition in libc.
> The patch also includes necessary code style changes (tab to spaces) in the
> header file in the MIPS #ifdef block touched by the change.
>
> Signed-off-by: Petar Jovanovic <address@hidden>
> ---
> v2:
>
> - the patch defines ARCH_HAS_SOCKET_TYPES for MIPS, SPARC and ALPHA
> - values for sock_type are defined for SPARC and ALPHA in socket.h
>
> linux-user/socket.h | 248
> +++++++++++++++++++++++++++++++++-----------------
> linux-user/syscall.c | 45 +++++----
> 2 files changed, 195 insertions(+), 98 deletions(-)
>
> diff --git a/linux-user/socket.h b/linux-user/socket.h
> index 339cae5..d2b05dc 100644
> --- a/linux-user/socket.h
> +++ b/linux-user/socket.h
> @@ -1,91 +1,104 @@
>
> #if defined(TARGET_MIPS)
> - // MIPS special values for constants
> -
> - /*
> - * For setsockopt(2)
> - *
> - * This defines are ABI conformant as far as Linux supports these ...
> - */
> - #define TARGET_SOL_SOCKET 0xffff
> -
> - #define TARGET_SO_DEBUG 0x0001 /* Record debugging information.
> */
> - #define TARGET_SO_REUSEADDR 0x0004 /* Allow reuse of local
> addresses. */
> - #define TARGET_SO_KEEPALIVE 0x0008 /* Keep connections alive and
> send
> - SIGPIPE when they die. */
> - #define TARGET_SO_DONTROUTE 0x0010 /* Don't do local routing. */
> - #define TARGET_SO_BROADCAST 0x0020 /* Allow transmission of
> - broadcast messages. */
> - #define TARGET_SO_LINGER 0x0080 /* Block on close of a reliable
> - socket to transmit pending data. */
> - #define TARGET_SO_OOBINLINE 0x0100 /* Receive out-of-band data
> in-band. */
> - #if 0
> - To add: #define TARGET_SO_REUSEPORT 0x0200 /* Allow local address
> and port reuse. */
> - #endif
> -
> - #define TARGET_SO_TYPE 0x1008 /* Compatible name for SO_STYLE.
> */
> - #define TARGET_SO_STYLE SO_TYPE /* Synonym */
> - #define TARGET_SO_ERROR 0x1007 /* get error status and clear */
> - #define TARGET_SO_SNDBUF 0x1001 /* Send buffer size. */
> - #define TARGET_SO_RCVBUF 0x1002 /* Receive buffer. */
> - #define TARGET_SO_SNDLOWAT 0x1003 /* send low-water mark */
> - #define TARGET_SO_RCVLOWAT 0x1004 /* receive low-water mark */
> - #define TARGET_SO_SNDTIMEO 0x1005 /* send timeout */
> - #define TARGET_SO_RCVTIMEO 0x1006 /* receive timeout */
> - #define TARGET_SO_ACCEPTCONN 0x1009
> -
> - /* linux-specific, might as well be the same as on i386 */
> - #define TARGET_SO_NO_CHECK 11
> - #define TARGET_SO_PRIORITY 12
> - #define TARGET_SO_BSDCOMPAT 14
> + /* MIPS special values for constants */
> +
> + /*
> + * For setsockopt(2)
> + *
> + * This defines are ABI conformant as far as Linux supports these ...
> + */
> + #define TARGET_SOL_SOCKET 0xffff
> +
> + #define TARGET_SO_DEBUG 0x0001 /* Record debugging information.
> */
> + #define TARGET_SO_REUSEADDR 0x0004 /* Allow reuse of local
> addresses. */
> + #define TARGET_SO_KEEPALIVE 0x0008 /* Keep connections alive and send
> + SIGPIPE when they die. */
> + #define TARGET_SO_DONTROUTE 0x0010 /* Don't do local routing. */
> + #define TARGET_SO_BROADCAST 0x0020 /* Allow transmission of
> + broadcast messages. */
> + #define TARGET_SO_LINGER 0x0080 /* Block on close of a reliable
> + * socket to transmit pending
> data.
> + */
> + #define TARGET_SO_OOBINLINE 0x0100 /* Receive out-of-band data
> in-band.
> + */
> + #if 0
> + /* To add: Allow local address and port reuse. */
> + #define TARGET_SO_REUSEPORT 0x0200
> + #endif
> +
> + #define TARGET_SO_TYPE 0x1008 /* Compatible name for SO_STYLE.
> */
> + #define TARGET_SO_STYLE SO_TYPE /* Synonym */
> + #define TARGET_SO_ERROR 0x1007 /* get error status and clear */
> + #define TARGET_SO_SNDBUF 0x1001 /* Send buffer size. */
> + #define TARGET_SO_RCVBUF 0x1002 /* Receive buffer. */
> + #define TARGET_SO_SNDLOWAT 0x1003 /* send low-water mark */
> + #define TARGET_SO_RCVLOWAT 0x1004 /* receive low-water mark */
> + #define TARGET_SO_SNDTIMEO 0x1005 /* send timeout */
> + #define TARGET_SO_RCVTIMEO 0x1006 /* receive timeout */
> + #define TARGET_SO_ACCEPTCONN 0x1009
>
> - #define TARGET_SO_PASSCRED 17
> - #define TARGET_SO_PEERCRED 18
> + /* linux-specific, might as well be the same as on i386 */
> + #define TARGET_SO_NO_CHECK 11
> + #define TARGET_SO_PRIORITY 12
> + #define TARGET_SO_BSDCOMPAT 14
>
> - /* Security levels - as per NRL IPv6 - don't actually do anything */
> - #define TARGET_SO_SECURITY_AUTHENTICATION 22
> - #define TARGET_SO_SECURITY_ENCRYPTION_TRANSPORT 23
> - #define TARGET_SO_SECURITY_ENCRYPTION_NETWORK 24
> + #define TARGET_SO_PASSCRED 17
> + #define TARGET_SO_PEERCRED 18
>
> - #define TARGET_SO_BINDTODEVICE 25
> + /* Security levels - as per NRL IPv6 - don't actually do anything */
> + #define TARGET_SO_SECURITY_AUTHENTICATION 22
> + #define TARGET_SO_SECURITY_ENCRYPTION_TRANSPORT 23
> + #define TARGET_SO_SECURITY_ENCRYPTION_NETWORK 24
>
> - /* Socket filtering */
> - #define TARGET_SO_ATTACH_FILTER 26
> - #define TARGET_SO_DETACH_FILTER 27
> + #define TARGET_SO_BINDTODEVICE 25
>
> - #define TARGET_SO_PEERNAME 28
> - #define TARGET_SO_TIMESTAMP 29
> - #define SCM_TIMESTAMP SO_TIMESTAMP
> -
> - #define TARGET_SO_PEERSEC 30
> - #define TARGET_SO_SNDBUFFORCE 31
> - #define TARGET_SO_RCVBUFFORCE 33
> -
> - /** sock_type - Socket types
> - *
> - * Please notice that for binary compat reasons MIPS has to
> - * override the enum sock_type in include/linux/net.h, so
> - * we define ARCH_HAS_SOCKET_TYPES here.
> - *
> - * @SOCK_DGRAM - datagram (conn.less) socket
> - * @SOCK_STREAM - stream (connection) socket
> - * @SOCK_RAW - raw socket
> - * @SOCK_RDM - reliably-delivered message
> - * @SOCK_SEQPACKET - sequential packet socket
> - * @SOCK_PACKET - linux specific way of getting packets at the dev
> level.
> - * For writing rarp and other similar things on the user
> level.
> - */
> - enum sock_type {
> - TARGET_SOCK_DGRAM = 1,
> - TARGET_SOCK_STREAM = 2,
> - TARGET_SOCK_RAW = 3,
> - TARGET_SOCK_RDM = 4,
> - TARGET_SOCK_SEQPACKET = 5,
> - TARGET_SOCK_DCCP = 6,
> - TARGET_SOCK_PACKET = 10,
> - };
> -
> - #define TARGET_SOCK_MAX (SOCK_PACKET + 1)
> + /* Socket filtering */
> + #define TARGET_SO_ATTACH_FILTER 26
> + #define TARGET_SO_DETACH_FILTER 27
> +
> + #define TARGET_SO_PEERNAME 28
> + #define TARGET_SO_TIMESTAMP 29
> + #define SCM_TIMESTAMP SO_TIMESTAMP
> +
> + #define TARGET_SO_PEERSEC 30
> + #define TARGET_SO_SNDBUFFORCE 31
> + #define TARGET_SO_RCVBUFFORCE 33
> +
> + /** sock_type - Socket types
> + *
> + * Please notice that for binary compat reasons MIPS has to
> + * override the enum sock_type in include/linux/net.h, so
> + * we define ARCH_HAS_SOCKET_TYPES here.
> + *
> + * @SOCK_DGRAM - datagram (conn.less) socket
> + * @SOCK_STREAM - stream (connection) socket
> + * @SOCK_RAW - raw socket
> + * @SOCK_RDM - reliably-delivered message
> + * @SOCK_SEQPACKET - sequential packet socket
> + * @SOCK_DCCP - Datagram Congestion Control Protocol socket
> + * @SOCK_PACKET - linux specific way of getting packets at the dev level.
> + * For writing rarp and other similar things on the user
> + * level.
> + * @SOCK_CLOEXEC - sets the close-on-exec (FD_CLOEXEC) flag.
> + * @SOCK_NONBLOCK - sets the O_NONBLOCK file status flag.
> + */
> +
> + #define ARCH_HAS_SOCKET_TYPES 1
> +
> + enum sock_type {
> + TARGET_SOCK_DGRAM = 1,
> + TARGET_SOCK_STREAM = 2,
> + TARGET_SOCK_RAW = 3,
> + TARGET_SOCK_RDM = 4,
> + TARGET_SOCK_SEQPACKET = 5,
> + TARGET_SOCK_DCCP = 6,
> + TARGET_SOCK_PACKET = 10,
> + TARGET_SOCK_CLOEXEC = 02000000,
> + TARGET_SOCK_NONBLOCK = 0200,
> + };
> +
> + #define TARGET_SOCK_MAX (TARGET_SOCK_PACKET + 1)
> + #define TARGET_SOCK_TYPE_MASK 0xf /* Covers up to TARGET_SOCK_MAX-1.
> */
>
> #elif defined(TARGET_ALPHA)
>
> @@ -156,8 +169,81 @@
> /* Instruct lower device to use last 4-bytes of skb data as FCS */
> #define TARGET_SO_NOFCS 43
>
> + /** sock_type - Socket types
> + *
> + * Please notice that for binary compat reasons ALPHA has to
> + * override the enum sock_type in include/linux/net.h, so
> + * we define ARCH_HAS_SOCKET_TYPES here.
> + *
> + * @SOCK_DGRAM - datagram (conn.less) socket
> + * @SOCK_STREAM - stream (connection) socket
> + * @SOCK_RAW - raw socket
> + * @SOCK_RDM - reliably-delivered message
> + * @SOCK_SEQPACKET - sequential packet socket
> + * @SOCK_DCCP - Datagram Congestion Control Protocol socket
> + * @SOCK_PACKET - linux specific way of getting packets at the dev level.
> + * For writing rarp and other similar things on the user
> + * level.
> + * @SOCK_CLOEXEC - sets the close-on-exec (FD_CLOEXEC) flag.
> + * @SOCK_NONBLOCK - sets the O_NONBLOCK file status flag.
> + */
> +
> + #define ARCH_HAS_SOCKET_TYPES 1
> +
> + enum sock_type {
> + TARGET_SOCK_STREAM = 1,
> + TARGET_SOCK_DGRAM = 2,
> + TARGET_SOCK_RAW = 3,
> + TARGET_SOCK_RDM = 4,
> + TARGET_SOCK_SEQPACKET = 5,
> + TARGET_SOCK_DCCP = 6,
> + TARGET_SOCK_PACKET = 10,
> + TARGET_SOCK_CLOEXEC = 010000000,
> + TARGET_SOCK_NONBLOCK = 010000000000,
> + };
> +
> + #define TARGET_SOCK_MAX (TARGET_SOCK_PACKET + 1)
> + #define TARGET_SOCK_TYPE_MASK 0xf /* Covers up to TARGET_SOCK_MAX-1.
> */
> #else
>
> +#if defined(TARGET_SPARC)
> + /** sock_type - Socket types
> + *
> + * Please notice that for binary compat reasons SPARC has to
> + * override the enum sock_type in include/linux/net.h, so
> + * we define ARCH_HAS_SOCKET_TYPES here.
> + *
> + * @SOCK_DGRAM - datagram (conn.less) socket
> + * @SOCK_STREAM - stream (connection) socket
> + * @SOCK_RAW - raw socket
> + * @SOCK_RDM - reliably-delivered message
> + * @SOCK_SEQPACKET - sequential packet socket
> + * @SOCK_DCCP - Datagram Congestion Control Protocol socket
> + * @SOCK_PACKET - linux specific way of getting packets at the dev level.
> + * For writing rarp and other similar things on the user
> + * level.
> + * @SOCK_CLOEXEC - sets the close-on-exec (FD_CLOEXEC) flag.
> + * @SOCK_NONBLOCK - sets the O_NONBLOCK file status flag.
> + */
> +
> + #define ARCH_HAS_SOCKET_TYPES 1
> +
> + enum sock_type {
> + TARGET_SOCK_STREAM = 1,
> + TARGET_SOCK_DGRAM = 2,
> + TARGET_SOCK_RAW = 3,
> + TARGET_SOCK_RDM = 4,
> + TARGET_SOCK_SEQPACKET = 5,
> + TARGET_SOCK_DCCP = 6,
> + TARGET_SOCK_PACKET = 10,
> + TARGET_SOCK_CLOEXEC = 020000000,
> + TARGET_SOCK_NONBLOCK = 040000,
> + };
> +
> + #define TARGET_SOCK_MAX (TARGET_SOCK_PACKET + 1)
> + #define TARGET_SOCK_TYPE_MASK 0xf /* Covers up to TARGET_SOCK_MAX-1.
> */
> +#endif
> +
> /* For setsockopt(2) */
> #define TARGET_SOL_SOCKET 1
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index ee82a2d..5b87c9d 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -1859,30 +1859,38 @@ static void unlock_iovec(struct iovec *vec, abi_ulong
> target_addr,
> free(vec);
> }
>
> -/* do_socket() Must return target values and target errnos. */
> -static abi_long do_socket(int domain, int type, int protocol)
> +#if defined(ARCH_HAS_SOCKET_TYPES)
> +static inline void target_to_host_sock_type(int *type)
> {
> -#if defined(TARGET_MIPS)
> - switch(type) {
> + int host_type = 0;
> + int target_type = *type;
> +
> + switch (target_type & TARGET_SOCK_TYPE_MASK) {
> case TARGET_SOCK_DGRAM:
> - type = SOCK_DGRAM;
> + host_type = SOCK_DGRAM;
> break;
> case TARGET_SOCK_STREAM:
> - type = SOCK_STREAM;
> - break;
> - case TARGET_SOCK_RAW:
> - type = SOCK_RAW;
> + host_type = SOCK_STREAM;
> break;
> - case TARGET_SOCK_RDM:
> - type = SOCK_RDM;
> - break;
> - case TARGET_SOCK_SEQPACKET:
> - type = SOCK_SEQPACKET;
> - break;
> - case TARGET_SOCK_PACKET:
> - type = SOCK_PACKET;
> + default:
> + host_type = target_type & TARGET_SOCK_TYPE_MASK;
> break;
> }
> + if (target_type & TARGET_SOCK_CLOEXEC) {
> + host_type |= SOCK_CLOEXEC;
> + }
> + if (target_type & TARGET_SOCK_NONBLOCK) {
> + host_type |= SOCK_NONBLOCK;
> + }
> + *type = host_type;
The problem I see with this way of handling the flags is that if the
kernel later adds a new flag value, QEMU will silently drop it. It means
that if the glibc tries to see it will think the kernel (and here QEMU)
supports it (as no error is returned), and will not use to the fallback
code. For that each processed flag should probably be removed from
target_type and it should be 0 at the end of the function.
Imagine for example SOCK_NONBLOCK is a new feature, it starts to be
supported by the glibc, but silently dropped by QEMU.
That said I agree it's purely hypothetical, as no new flags has been
added recently or is planned to be added. We can also decide to fix that
when a new flag is added. What the other people (the Cc:ed one) think?
> +}
> +#endif
> +
> +/* do_socket() Must return target values and target errnos. */
> +static abi_long do_socket(int domain, int type, int protocol)
> +{
> +#if defined(ARCH_HAS_SOCKET_TYPES)
> + target_to_host_sock_type(&type);
> #endif
> if (domain == PF_NETLINK)
> return -EAFNOSUPPORT; /* do not NETLINK socket connections possible
> */
> @@ -2116,6 +2124,9 @@ static abi_long do_socketpair(int domain, int type, int
> protocol,
> int tab[2];
> abi_long ret;
>
> +#if defined(ARCH_HAS_SOCKET_TYPES)
> + target_to_host_sock_type(&type);
> +#endif
> ret = get_errno(socketpair(domain, type, protocol, tab));
> if (!is_error(ret)) {
> if (put_user_s32(tab[0], target_tab_addr)
Otherwise the patch looks fine.
--
Aurelien Jarno GPG: 1024D/F1BCDB73
address@hidden http://www.aurel32.net