syscall.c

qemu性能直逼VMware的仿真器QEMU 的模擬速度約為實機的 25％；約為 Bochs 的 60 倍。Plex86、User-Mode-Linux、VMware 和 Virtual PC 則比

        int len = tswapl(target_cmsg->cmsg_len) 
                  - TARGET_CMSG_ALIGN(sizeof (struct target_cmsghdr));

        space += CMSG_SPACE(len);
        if (space > msgh->msg_controllen) {
            space -= CMSG_SPACE(len);
            gemu_log("Host cmsg overflow\n");
            break;
        }

        cmsg->cmsg_level = tswap32(target_cmsg->cmsg_level);
        cmsg->cmsg_type = tswap32(target_cmsg->cmsg_type);
        cmsg->cmsg_len = CMSG_LEN(len);

        if (cmsg->cmsg_level != TARGET_SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
            gemu_log("Unsupported ancillary data: %d/%d\n", cmsg->cmsg_level, cmsg->cmsg_type);
            memcpy(data, target_data, len);
        } else {
            int *fd = (int *)data;
            int *target_fd = (int *)target_data;
            int i, numfds = len / sizeof(int);

            for (i = 0; i < numfds; i++)
                fd[i] = tswap32(target_fd[i]);
        }

        cmsg = CMSG_NXTHDR(msgh, cmsg);
        target_cmsg = TARGET_CMSG_NXTHDR(target_msgh, target_cmsg);
    }

    msgh->msg_controllen = space;
}

/* ??? Should this also swap msgh->name?  */
static inline void host_to_target_cmsg(struct target_msghdr *target_msgh,
                                       struct msghdr *msgh)
{
    struct cmsghdr *cmsg = CMSG_FIRSTHDR(msgh);
    struct target_cmsghdr *target_cmsg = TARGET_CMSG_FIRSTHDR(target_msgh);
    socklen_t space = 0;

    while (cmsg && target_cmsg) {
        void *data = CMSG_DATA(cmsg);
        void *target_data = TARGET_CMSG_DATA(target_cmsg);

        int len = cmsg->cmsg_len - CMSG_ALIGN(sizeof (struct cmsghdr));

        space += TARGET_CMSG_SPACE(len);
        if (space > tswapl(target_msgh->msg_controllen)) {
            space -= TARGET_CMSG_SPACE(len);
            gemu_log("Target cmsg overflow\n");
            break;
        }

        target_cmsg->cmsg_level = tswap32(cmsg->cmsg_level);
        target_cmsg->cmsg_type = tswap32(cmsg->cmsg_type);
        target_cmsg->cmsg_len = tswapl(TARGET_CMSG_LEN(len));

        if (cmsg->cmsg_level != TARGET_SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
            gemu_log("Unsupported ancillary data: %d/%d\n", cmsg->cmsg_level, cmsg->cmsg_type);
            memcpy(target_data, data, len);
        } else {
            int *fd = (int *)data;
            int *target_fd = (int *)target_data;
            int i, numfds = len / sizeof(int);

            for (i = 0; i < numfds; i++)
                target_fd[i] = tswap32(fd[i]);
        }

        cmsg = CMSG_NXTHDR(msgh, cmsg);
        target_cmsg = TARGET_CMSG_NXTHDR(target_msgh, target_cmsg);
    }

    msgh->msg_controllen = tswapl(space);
}

static long do_setsockopt(int sockfd, int level, int optname, 
                          target_ulong optval, socklen_t optlen)
{
    int val, ret;
            
    switch(level) {
    case SOL_TCP:
        /* TCP options all take an 'int' value.  */
        if (optlen < sizeof(uint32_t))
            return -EINVAL;
        
        val = tget32(optval);
        ret = get_errno(setsockopt(sockfd, level, optname, &val, sizeof(val)));
        break;
    case SOL_IP:
        switch(optname) {
        case IP_TOS:
        case IP_TTL:
        case IP_HDRINCL:
        case IP_ROUTER_ALERT:
        case IP_RECVOPTS:
        case IP_RETOPTS:
        case IP_PKTINFO:
        case IP_MTU_DISCOVER:
        case IP_RECVERR:
        case IP_RECVTOS:
#ifdef IP_FREEBIND
        case IP_FREEBIND:
#endif
        case IP_MULTICAST_TTL:
        case IP_MULTICAST_LOOP:
            val = 0;
            if (optlen >= sizeof(uint32_t)) {
                val = tget32(optval);
            } else if (optlen >= 1) {
                val = tget8(optval);
            }
            ret = get_errno(setsockopt(sockfd, level, optname, &val, sizeof(val)));
            break;
        default:
            goto unimplemented;
        }
        break;
    case TARGET_SOL_SOCKET:
        switch (optname) {
            /* Options with 'int' argument.  */
        case TARGET_SO_DEBUG:
		optname = SO_DEBUG;
		break;
        case TARGET_SO_REUSEADDR:
		optname = SO_REUSEADDR;
		break;
        case TARGET_SO_TYPE:
		optname = SO_TYPE;
		break;
        case TARGET_SO_ERROR:
		optname = SO_ERROR;
		break;
        case TARGET_SO_DONTROUTE:
		optname = SO_DONTROUTE;
		break;
        case TARGET_SO_BROADCAST:
		optname = SO_BROADCAST;
		break;
        case TARGET_SO_SNDBUF:
		optname = SO_SNDBUF;
		break;
        case TARGET_SO_RCVBUF:
		optname = SO_RCVBUF;
		break;
        case TARGET_SO_KEEPALIVE:
		optname = SO_KEEPALIVE;
		break;
        case TARGET_SO_OOBINLINE:
		optname = SO_OOBINLINE;
		break;
        case TARGET_SO_NO_CHECK:
		optname = SO_NO_CHECK;
		break;
        case TARGET_SO_PRIORITY:
		optname = SO_PRIORITY;
		break;
#ifdef SO_BSDCOMPAT
        case TARGET_SO_BSDCOMPAT:
		optname = SO_BSDCOMPAT;
		break;
#endif
        case TARGET_SO_PASSCRED:
		optname = SO_PASSCRED;
		break;
        case TARGET_SO_TIMESTAMP:
		optname = SO_TIMESTAMP;
		break;
        case TARGET_SO_RCVLOWAT:
		optname = SO_RCVLOWAT;
		break;
        case TARGET_SO_RCVTIMEO:
		optname = SO_RCVTIMEO;
		break;
        case TARGET_SO_SNDTIMEO:
		optname = SO_SNDTIMEO;
		break;
            break;
        default:
            goto unimplemented;
        }
	if (optlen < sizeof(uint32_t))
	return -EINVAL;

	val = tget32(optval);
	ret = get_errno(setsockopt(sockfd, SOL_SOCKET, optname, &val, sizeof(val)));
        break;
    default:
    unimplemented:
        gemu_log("Unsupported setsockopt level=%d optname=%d \n", level, optname);
        ret = -ENOSYS;
    }
    return ret;
}

static long do_getsockopt(int sockfd, int level, int optname, 
                          target_ulong optval, target_ulong optlen)
{
    int len, lv, val, ret;

    switch(level) {
    case TARGET_SOL_SOCKET:
    	level = SOL_SOCKET;
	switch (optname) {
	case TARGET_SO_LINGER:
	case TARGET_SO_RCVTIMEO:
	case TARGET_SO_SNDTIMEO:
	case TARGET_SO_PEERCRED:
	case TARGET_SO_PEERNAME:
	    /* These don't just return a single integer */
	    goto unimplemented;
        default:
            goto int_case;
        }
        break;
    case SOL_TCP:
        /* TCP options all take an 'int' value.  */
    int_case:
        len = tget32(optlen);
        if (len < 0)
            return -EINVAL;
        lv = sizeof(int);
        ret = get_errno(getsockopt(sockfd, level, optname, &val, &lv));
        if (ret < 0)
            return ret;
        val = tswap32(val);
        if (len > lv)
            len = lv;
        if (len == 4)
            tput32(optval, val);
        else
            tput8(optval, val);
        tput32(optlen, len);
        break;
    case SOL_IP:
        switch(optname) {
        case IP_TOS:
        case IP_TTL:
        case IP_HDRINCL:
        case IP_ROUTER_ALERT:
        case IP_RECVOPTS:
        case IP_RETOPTS:
        case IP_PKTINFO:
        case IP_MTU_DISCOVER:
        case IP_RECVERR:
        case IP_RECVTOS:
#ifdef IP_FREEBIND
        case IP_FREEBIND:
#endif
        case IP_MULTICAST_TTL:
        case IP_MULTICAST_LOOP:
            len = tget32(optlen);
            if (len < 0)
                return -EINVAL;
            lv = sizeof(int);
            ret = get_errno(getsockopt(sockfd, level, optname, &val, &lv));
            if (ret < 0)
                return ret;
            if (len < sizeof(int) && len > 0 && val >= 0 && val < 255) {
                len = 1;
                tput32(optlen, len);
                tput8(optval, val);
            } else {
                if (len > sizeof(int))
                    len = sizeof(int);
                tput32(optlen, len);
                tput32(optval, val);
            }
            break;
        default:
            goto unimplemented;
        }
        break;
    default:
    unimplemented:
        gemu_log("getsockopt level=%d optname=%d not yet supported\n",
                 level, optname);
        ret = -ENOSYS;
        break;
    }
    return ret;
}

static void lock_iovec(struct iovec *vec, target_ulong target_addr,
                       int count, int copy)
{
    struct target_iovec *target_vec;
    target_ulong base;
    int i;

    target_vec = lock_user(target_addr, count * sizeof(struct target_iovec), 1);
    for(i = 0;i < count; i++) {
        base = tswapl(target_vec[i].iov_base);
        vec[i].iov_len = tswapl(target_vec[i].iov_len);
        vec[i].iov_base = lock_user(base, vec[i].iov_len, copy);
    }
    unlock_user (target_vec, target_addr, 0);
}

static void unlock_iovec(struct iovec *vec, target_ulong target_addr,
                         int count, int copy)
{
    struct target_iovec *target_vec;
    target_ulong base;
    int i;

    target_vec = lock_user(target_addr, count * sizeof(struct target_iovec), 1);
    for(i = 0;i < count; i++) {
        base = tswapl(target_vec[i].iov_base);
        unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
    }
    unlock_user (target_vec, target_addr, 0);
}

static long do_socket(int domain, int type, int protocol)
{
#if defined(TARGET_MIPS)
    switch(type) {
    case TARGET_SOCK_DGRAM:
        type = SOCK_DGRAM;
        break;
    case TARGET_SOCK_STREAM:
        type = SOCK_STREAM;
        break;
    case TARGET_SOCK_RAW:
        type = SOCK_RAW;
        break;
    case TARGET_SOCK_RDM:
        type = SOCK_RDM;
        break;
    case TARGET_SOCK_SEQPACKET:
        type = SOCK_SEQPACKET;
        break;
    case TARGET_SOCK_PACKET:
        type = SOCK_PACKET;
        break;
    }
#endif
    return get_errno(socket(domain, type, protocol));
}

static long do_bind(int sockfd, target_ulong target_addr,
                    socklen_t addrlen)
{
    void *addr = alloca(addrlen);
    
    target_to_host_sockaddr(addr, target_addr, addrlen);
    return get_errno(bind(sockfd, addr, addrlen));
}

static long do_connect(int sockfd, target_ulong target_addr,
                    socklen_t addrlen)
{
    void *addr = alloca(addrlen);
    
    target_to_host_sockaddr(addr, target_addr, addrlen);
    return get_errno(connect(sockfd, addr, addrlen));
}

static long do_sendrecvmsg(int fd, target_ulong target_msg,
                           int flags, int send)
{
    long ret;
    struct target_msghdr *msgp;
    struct msghdr msg;
    int count;
    struct iovec *vec;
    target_ulong target_vec;

    lock_user_struct(msgp, target_msg, 1);
    if (msgp->msg_name) {
        msg.msg_namelen = tswap32(msgp->msg_namelen);
        msg.msg_name = alloca(msg.msg_namelen);
        target_to_host_sockaddr(msg.msg_name, tswapl(msgp->msg_name),
                                msg.msg_namelen);
    } else {
        msg.msg_name = NULL;
        msg.msg_namelen = 0;
    }
    msg.msg_controllen = 2 * tswapl(msgp->msg_controllen);
    msg.msg_control = alloca(msg.msg_controllen);
    msg.msg_flags = tswap32(msgp->msg_flags);
    
    count = tswapl(msgp->msg_iovlen);
    vec = alloca(count * sizeof(struct iovec));
    target_vec = tswapl(msgp->msg_iov);
    lock_iovec(vec, target_vec, count, send);
    msg.msg_iovlen = count;
    msg.msg_iov = vec;
    
    if (send) {
        target_to_host_cmsg(&msg, msgp);
        ret = get_errno(sendmsg(fd, &msg, flags));
    } else {
        ret = get_errno(recvmsg(fd, &msg, flags));
        if (!is_error(ret))
            host_to_target_cmsg(msgp, &msg);
    }
    unlock_iovec(vec, target_vec, count, !send);
    return ret;
}

static long do_accept(int fd, target_ulong target_addr,
                      target_ulong target_addrlen)
{
    socklen_t addrlen = tget32(target_addrlen);
    void *addr = alloca(addrlen);
    long ret;

    ret = get_errno(accept(fd, addr, &addrlen));
    if (!is_error(ret)) {
        host_to_target_sockaddr(target_addr, addr, addrlen);
        tput32(target_addrlen, addrlen);
    }
    return ret;
}

static long do_getpeername(int fd, target_ulong target_addr,
                           target_ulong target_addrlen)
{
    socklen_t addrlen = tget32(target_addrlen);
    void *addr = alloca(target_addrlen);
    long ret;

    ret = get_errno(getpeername(fd, addr, &addrlen));
    if (!is_error(ret)) {
        host_to_target_sockaddr(target_addr, addr, addrlen);
        tput32(target_addrlen, addrlen);
    }
    return ret;
}