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

static long do_getsockname(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(getsockname(fd, addr, &addrlen));
    if (!is_error(ret)) {
        host_to_target_sockaddr(target_addr, addr, addrlen);
        tput32(target_addrlen, addrlen);
    }
    return ret;
}

static long do_socketpair(int domain, int type, int protocol,
                          target_ulong target_tab)
{
    int tab[2];
    long ret;

    ret = get_errno(socketpair(domain, type, protocol, tab));
    if (!is_error(ret)) {
        tput32(target_tab, tab[0]);
        tput32(target_tab + 4, tab[1]);
    }
    return ret;
}

static long do_sendto(int fd, target_ulong msg, size_t len, int flags,
                      target_ulong target_addr, socklen_t addrlen)
{
    void *addr;
    void *host_msg;
    long ret;

    host_msg = lock_user(msg, len, 1);
    if (target_addr) {
        addr = alloca(addrlen);
        target_to_host_sockaddr(addr, target_addr, addrlen);
        ret = get_errno(sendto(fd, host_msg, len, flags, addr, addrlen));
    } else {
        ret = get_errno(send(fd, host_msg, len, flags));
    }
    unlock_user(host_msg, msg, 0);
    return ret;
}

static long do_recvfrom(int fd, target_ulong msg, size_t len, int flags,
                        target_ulong target_addr, target_ulong target_addrlen)
{
    socklen_t addrlen;
    void *addr;
    void *host_msg;
    long ret;

    host_msg = lock_user(msg, len, 0);
    if (target_addr) {
        addrlen = tget32(target_addrlen);
        addr = alloca(addrlen);
        ret = get_errno(recvfrom(fd, host_msg, len, flags, addr, &addrlen));
    } else {
        addr = NULL; /* To keep compiler quiet.  */
        ret = get_errno(recv(fd, host_msg, len, flags));
    }
    if (!is_error(ret)) {
        if (target_addr) {
            host_to_target_sockaddr(target_addr, addr, addrlen);
            tput32(target_addrlen, addrlen);
        }
        unlock_user(host_msg, msg, len);
    } else {
        unlock_user(host_msg, msg, 0);
    }
    return ret;
}

static long do_socketcall(int num, target_ulong vptr)
{
    long ret;
    const int n = sizeof(target_ulong);

    switch(num) {
    case SOCKOP_socket:
	{
            int domain = tgetl(vptr);
            int type = tgetl(vptr + n);
            int protocol = tgetl(vptr + 2 * n);
            ret = do_socket(domain, type, protocol);
	}
        break;
    case SOCKOP_bind:
	{
            int sockfd = tgetl(vptr);
            target_ulong target_addr = tgetl(vptr + n);
            socklen_t addrlen = tgetl(vptr + 2 * n);
            ret = do_bind(sockfd, target_addr, addrlen);
        }
        break;
    case SOCKOP_connect:
        {
            int sockfd = tgetl(vptr);
            target_ulong target_addr = tgetl(vptr + n);
            socklen_t addrlen = tgetl(vptr + 2 * n);
            ret = do_connect(sockfd, target_addr, addrlen);
        }
        break;
    case SOCKOP_listen:
        {
            int sockfd = tgetl(vptr);
            int backlog = tgetl(vptr + n);
            ret = get_errno(listen(sockfd, backlog));
        }
        break;
    case SOCKOP_accept:
        {
            int sockfd = tgetl(vptr);
            target_ulong target_addr = tgetl(vptr + n);
            target_ulong target_addrlen = tgetl(vptr + 2 * n);
            ret = do_accept(sockfd, target_addr, target_addrlen);
        }
        break;
    case SOCKOP_getsockname:
        {
            int sockfd = tgetl(vptr);
            target_ulong target_addr = tgetl(vptr + n);
            target_ulong target_addrlen = tgetl(vptr + 2 * n);
            ret = do_getsockname(sockfd, target_addr, target_addrlen);
        }
        break;
    case SOCKOP_getpeername:
        {
            int sockfd = tgetl(vptr);
            target_ulong target_addr = tgetl(vptr + n);
            target_ulong target_addrlen = tgetl(vptr + 2 * n);
            ret = do_getpeername(sockfd, target_addr, target_addrlen);
        }
        break;
    case SOCKOP_socketpair:
        {
            int domain = tgetl(vptr);
            int type = tgetl(vptr + n);
            int protocol = tgetl(vptr + 2 * n);
            target_ulong tab = tgetl(vptr + 3 * n);
            ret = do_socketpair(domain, type, protocol, tab);
        }
        break;
    case SOCKOP_send:
        {
            int sockfd = tgetl(vptr);
            target_ulong msg = tgetl(vptr + n);
            size_t len = tgetl(vptr + 2 * n);
            int flags = tgetl(vptr + 3 * n);
            ret = do_sendto(sockfd, msg, len, flags, 0, 0);
        }
        break;
    case SOCKOP_recv:
        {
            int sockfd = tgetl(vptr);
            target_ulong msg = tgetl(vptr + n);
            size_t len = tgetl(vptr + 2 * n);
            int flags = tgetl(vptr + 3 * n);
            ret = do_recvfrom(sockfd, msg, len, flags, 0, 0);
        }
        break;
    case SOCKOP_sendto:
        {
            int sockfd = tgetl(vptr);
            target_ulong msg = tgetl(vptr + n);
            size_t len = tgetl(vptr + 2 * n);
            int flags = tgetl(vptr + 3 * n);
            target_ulong addr = tgetl(vptr + 4 * n);
            socklen_t addrlen = tgetl(vptr + 5 * n);
            ret = do_sendto(sockfd, msg, len, flags, addr, addrlen);
        }
        break;
    case SOCKOP_recvfrom:
        {
            int sockfd = tgetl(vptr);
            target_ulong msg = tgetl(vptr + n);
            size_t len = tgetl(vptr + 2 * n);
            int flags = tgetl(vptr + 3 * n);
            target_ulong addr = tgetl(vptr + 4 * n);
            target_ulong addrlen = tgetl(vptr + 5 * n);
            ret = do_recvfrom(sockfd, msg, len, flags, addr, addrlen);
        }
        break;
    case SOCKOP_shutdown:
        {
            int sockfd = tgetl(vptr);
            int how = tgetl(vptr + n);

            ret = get_errno(shutdown(sockfd, how));
        }
        break;
    case SOCKOP_sendmsg:
    case SOCKOP_recvmsg:
        {
            int fd;
            target_ulong target_msg;
            int flags;

            fd = tgetl(vptr);
            target_msg = tgetl(vptr + n);
            flags = tgetl(vptr + 2 * n);

            ret = do_sendrecvmsg(fd, target_msg, flags, 
                                 (num == SOCKOP_sendmsg));
        }
        break;
    case SOCKOP_setsockopt:
        {
            int sockfd = tgetl(vptr);
            int level = tgetl(vptr + n);
            int optname = tgetl(vptr + 2 * n);
            target_ulong optval = tgetl(vptr + 3 * n);
            socklen_t optlen = tgetl(vptr + 4 * n);

            ret = do_setsockopt(sockfd, level, optname, optval, optlen);
        }
        break;
    case SOCKOP_getsockopt:
        {
            int sockfd = tgetl(vptr);
            int level = tgetl(vptr + n);
            int optname = tgetl(vptr + 2 * n);
            target_ulong optval = tgetl(vptr + 3 * n);
            target_ulong poptlen = tgetl(vptr + 4 * n);

            ret = do_getsockopt(sockfd, level, optname, optval, poptlen);
        }
        break;
    default:
        gemu_log("Unsupported socketcall: %d\n", num);
        ret = -ENOSYS;
        break;
    }
    return ret;
}

#define N_SHM_REGIONS	32

static struct shm_region {
    uint32_t	start;
    uint32_t	size;
} shm_regions[N_SHM_REGIONS];

union semun {
	int val;
	struct senid_ds *buf;
	unsigned short *array;
};

/* ??? This only works with linear mappings.  */
static long do_ipc(long call, long first, long second, long third,
		   long ptr, long fifth)
{
    int version;
    long ret = 0;
    unsigned long raddr;
    struct shmid_ds shm_info;
    int i;

    version = call >> 16;
    call &= 0xffff;

    switch (call) {
    case IPCOP_semop:
        ret = get_errno(semop(first,(struct sembuf *) ptr, second));
        break;

    case IPCOP_semget:
        ret = get_errno(semget(first, second, third));
        break;

    case IPCOP_semctl:
        ret = get_errno(semctl(first, second, third, ((union semun*)ptr)->val));

        break;

    case IPCOP_semtimedop:
        gemu_log("Unsupported ipc call: %ld (version %d)\n", call, version);
        ret = -ENOSYS;
        break;

	case IPCOP_msgget:
		ret = get_errno(msgget(first, second));
		break;

	case IPCOP_msgsnd:
		ret = get_errno(msgsnd(first, (struct msgbuf *) ptr, second, third));
		break;

	case IPCOP_msgctl:
		ret = get_errno(msgctl(first, second, (struct msqid_ds *) ptr));
		break;

	case IPCOP_msgrcv:
		{
			struct ipc_kludge
			{
				void *__unbounded msgp;
				long int msgtyp;
			};

			struct ipc_kludge *foo = (struct ipc_kludge *) ptr;
			struct msgbuf *msgp = (struct msgbuf *) foo->msgp;

			ret = get_errno(msgrcv(first, msgp, second, 0, third));

		}
		break;

    case IPCOP_shmat:
	/* SHM_* flags are the same on all linux platforms */
	ret = get_errno((long) shmat(first, (void *) ptr, second));
        if (is_error(ret))
            break;
        raddr = ret;
	/* find out the length of the shared memory segment */
        
        ret = get_errno(shmctl(first, IPC_STAT, &shm_info));
        if (is_error(ret)) {
            /* can't get length, bail out */
            shmdt((void *) raddr);
	    break;
	}
	page_set_flags(raddr, raddr + shm_info.shm_segsz,
		       PAGE_VALID | PAGE_READ |
		       ((second & SHM_RDONLY)? 0: PAGE_WRITE));
	for (i = 0; i < N_SHM_REGIONS; ++i) {
	    if (shm_regions[i].start == 0) {
		shm_regions[i].start = raddr;
		shm_regions[i].size = shm_info.shm_segsz;
                break;
	    }
	}
	if (put_user(raddr, (uint32_t *)third))
            return -EFAULT;
        ret = 0;
	break;
    case IPCOP_shmdt:
	for (i = 0; i < N_SHM_REGIONS; ++i) {
	    if (shm_regions[i].start == ptr) {
		shm_regions[i].start = 0;
		page_set_flags(ptr, shm_regions[i].size, 0);
		break;
	    }
	}
	ret = get_errno(shmdt((void *) ptr));
	break;

    case IPCOP_shmget:
	/* IPC_* flag values are the same on all linux platforms */
	ret = get_errno(shmget(first, second, third));
	break;

	/* IPC_* and SHM_* command values are the same on all linux platforms */
    case IPCOP_shmctl:
        switch(second) {
        case IPC_RMID:
        case SHM_LOCK:
        case SHM_UNLOCK:
            ret = get_errno(shmctl(first, second, NULL));
            break;
        default:
            goto unimplemented;
        }
        break;
    default:
    unimplemented:
	gemu_log("Unsupported ipc call: %ld (version %d)\n", call, version);
	ret = -ENOSYS;
	break;
    }
    return ret;
}

/* kernel structure types definitions */
#define IFNAMSIZ        16

#define STRUCT(name, list...) STRUCT_ ## name,
#define STRUCT_SPECIAL(name) STRUCT_ ## name,
enum {
#include "syscall_types.h"
};
#undef STRUCT
#undef STRUCT_SPECIAL

#define STRUCT(name, list...) const argtype struct_ ## name ## _def[] = { list, TYPE_NULL };
#define STRUCT_SPECIAL(name)
#include "syscall_types.h"
#undef STRUCT
#undef STRUCT_SPECIAL

typedef struct IOCTLEntry {
    unsigned int target_cmd;
    unsigned int host_cmd;
    const char *name;
    int access;
    const argtype arg_type[5];
} IOCTLEntry;

#define IOC_R 0x0001
#define IOC_W 0x0002
#define IOC_RW (IOC_R | IOC_W)

#define MAX_STRUCT_SIZE 4096

IOCTLEntry ioctl_entries[] = {
#define IOCTL(cmd, access, types...) \
    { TARGET_ ## cmd, cmd, #cmd, access, { types } },
#include "ioctls.h"
    { 0, 0, },
};

/* ??? Implement proper locking for ioctls.  */
static long do_ioctl(long fd, long cmd, long arg)
{
    const IOCTLEntry *ie;
    const argtype *arg_type;
    long ret;
    uint8_t buf_temp[MAX_STRUCT_SIZE];
    int target_size;
    void *argptr;

    ie = ioctl_entries;
    for(;;) {
        if (ie->target_cmd == 0) {
            gemu_log("Unsupported ioctl: cmd=0x%04lx\n", cmd);
            return -ENOSYS;
        }
        if (ie->target_cmd == cmd)
            break;
        ie++;