root/net/compat.c

/* 
 * 32bit Socket syscall emulation. Based on arch/sparc64/kernel/sys_sparc32.c.
 *
 * Copyright (C) 2000           VA Linux Co
 * Copyright (C) 2000           Don Dugger <n0ano@valinux.com>
 * Copyright (C) 1999           Arun Sharma <arun.sharma@intel.com>
 * Copyright (C) 1997,1998      Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997           David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 2000           Hewlett-Packard Co.
 * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 2000,2001      Andi Kleen, SuSE Labs 
 */

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/file.h>
#include <linux/icmpv6.h>
#include <linux/socket.h>
#include <linux/syscalls.h>
#include <linux/filter.h>
#include <linux/compat.h>
#include <linux/netfilter_ipv4/ip_tables.h>

#include <net/scm.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <net/compat.h>

static inline int iov_from_user_compat_to_kern(struct iovec *kiov,
                                          struct compat_iovec __user *uiov32,
                                          int niov)
{
        int tot_len = 0;

        while(niov > 0) {
                compat_uptr_t buf;
                compat_size_t len;

                if(get_user(len, &uiov32->iov_len) ||
                   get_user(buf, &uiov32->iov_base)) {
                        tot_len = -EFAULT;
                        break;
                }
                tot_len += len;
                kiov->iov_base = compat_ptr(buf);
                kiov->iov_len = (__kernel_size_t) len;
                uiov32++;
                kiov++;
                niov--;
        }
        return tot_len;
}

int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
{
        compat_uptr_t tmp1, tmp2, tmp3;

        if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
            __get_user(tmp1, &umsg->msg_name) ||
            __get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
            __get_user(tmp2, &umsg->msg_iov) ||
            __get_user(kmsg->msg_iovlen, &umsg->msg_iovlen) ||
            __get_user(tmp3, &umsg->msg_control) ||
            __get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
            __get_user(kmsg->msg_flags, &umsg->msg_flags))
                return -EFAULT;
        kmsg->msg_name = compat_ptr(tmp1);
        kmsg->msg_iov = compat_ptr(tmp2);
        kmsg->msg_control = compat_ptr(tmp3);
        return 0;
}

/* I've named the args so it is easy to tell whose space the pointers are in. */
int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *kern_iov,
                   char *kern_address, int mode)
{
        int tot_len;

        if(kern_msg->msg_namelen) {
                if(mode==VERIFY_READ) {
                        int err = move_addr_to_kernel(kern_msg->msg_name,
                                                      kern_msg->msg_namelen,
                                                      kern_address);
                        if(err < 0)
                                return err;
                }
                kern_msg->msg_name = kern_address;
        } else
                kern_msg->msg_name = NULL;

        if(kern_msg->msg_iovlen > UIO_FASTIOV) {
                kern_iov = kmalloc(kern_msg->msg_iovlen * sizeof(struct iovec),
                                   GFP_KERNEL);
                if(!kern_iov)
                        return -ENOMEM;
        }

        tot_len = iov_from_user_compat_to_kern(kern_iov,
                                          (struct compat_iovec __user *)kern_msg->msg_iov,
                                          kern_msg->msg_iovlen);
        if(tot_len >= 0)
                kern_msg->msg_iov = kern_iov;
        else if(kern_msg->msg_iovlen > UIO_FASTIOV)
                kfree(kern_iov);

        return tot_len;
}

/* Bleech... */
#define CMSG_COMPAT_ALIGN(len)  ALIGN((len), sizeof(s32))

#define CMSG_COMPAT_DATA(cmsg)                          \
        ((void __user *)((char __user *)(cmsg) + CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr))))
#define CMSG_COMPAT_SPACE(len)                          \
        (CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)) + CMSG_COMPAT_ALIGN(len))
#define CMSG_COMPAT_LEN(len)                            \
        (CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)) + (len))

#define CMSG_COMPAT_FIRSTHDR(msg)                       \
        (((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ?     \
         (struct compat_cmsghdr __user *)((msg)->msg_control) :         \
         (struct compat_cmsghdr __user *)NULL)

static inline struct compat_cmsghdr __user *cmsg_compat_nxthdr(struct msghdr *msg,
                struct compat_cmsghdr __user *cmsg, int cmsg_len)
{
        char __user *ptr = (char __user *)cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
        if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
                        msg->msg_controllen)
                return NULL;
        return (struct compat_cmsghdr __user *)ptr;
}

/* There is a lot of hair here because the alignment rules (and
 * thus placement) of cmsg headers and length are different for
 * 32-bit apps.  -DaveM
 */
int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg,
                               unsigned char *stackbuf, int stackbuf_size)
{
        struct compat_cmsghdr __user *ucmsg;
        struct cmsghdr *kcmsg, *kcmsg_base;
        compat_size_t ucmlen;
        __kernel_size_t kcmlen, tmp;

        kcmlen = 0;
        kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
        ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
        while(ucmsg != NULL) {
                if(get_user(ucmlen, &ucmsg->cmsg_len))
                        return -EFAULT;

                /* Catch bogons. */
                if(CMSG_COMPAT_ALIGN(ucmlen) <
                   CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)))
                        return -EINVAL;
                if((unsigned long)(((char __user *)ucmsg - (char __user *)kmsg->msg_control)
                                   + ucmlen) > kmsg->msg_controllen)
                        return -EINVAL;

                tmp = ((ucmlen - CMSG_COMPAT_ALIGN(sizeof(*ucmsg))) +
                       CMSG_ALIGN(sizeof(struct cmsghdr)));
                kcmlen += tmp;
                ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
        }
        if(kcmlen == 0)
                return -EINVAL;

        /* The kcmlen holds the 64-bit version of the control length.
         * It may not be modified as we do not stick it into the kmsg
         * until we have successfully copied over all of the data
         * from the user.
         */
        if(kcmlen > stackbuf_size)
                kcmsg_base = kcmsg = kmalloc(kcmlen, GFP_KERNEL);
        if(kcmsg == NULL)
                return -ENOBUFS;

        /* Now copy them over neatly. */
        memset(kcmsg, 0, kcmlen);
        ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
        while(ucmsg != NULL) {
                __get_user(ucmlen, &ucmsg->cmsg_len);
                tmp = ((ucmlen - CMSG_COMPAT_ALIGN(sizeof(*ucmsg))) +
                       CMSG_ALIGN(sizeof(struct cmsghdr)));
                kcmsg->cmsg_len = tmp;
                __get_user(kcmsg->cmsg_level, &ucmsg->cmsg_level);
                __get_user(kcmsg->cmsg_type, &ucmsg->cmsg_type);

                /* Copy over the data. */
                if(copy_from_user(CMSG_DATA(kcmsg),
                                  CMSG_COMPAT_DATA(ucmsg),
                                  (ucmlen - CMSG_COMPAT_ALIGN(sizeof(*ucmsg)))))
                        goto out_free_efault;

                /* Advance. */
                kcmsg = (struct cmsghdr *)((char *)kcmsg + CMSG_ALIGN(tmp));
                ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
        }

        /* Ok, looks like we made it.  Hook it up and return success. */
        kmsg->msg_control = kcmsg_base;
        kmsg->msg_controllen = kcmlen;
        return 0;

out_free_efault:
        if(kcmsg_base != (struct cmsghdr *)stackbuf)
                kfree(kcmsg_base);
        return -EFAULT;
}

int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data)
{
        struct compat_timeval ctv;
        struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
        struct compat_cmsghdr cmhdr;
        int cmlen;

        if(cm == NULL || kmsg->msg_controllen < sizeof(*cm)) {
                kmsg->msg_flags |= MSG_CTRUNC;
                return 0; /* XXX: return error? check spec. */
        }

        if (level == SOL_SOCKET && type == SO_TIMESTAMP) { 
                struct timeval *tv = (struct timeval *)data;
                ctv.tv_sec = tv->tv_sec;
                ctv.tv_usec = tv->tv_usec;
                data = &ctv;
                len = sizeof(struct compat_timeval);
        } 
        
        cmlen = CMSG_COMPAT_LEN(len);
        if(kmsg->msg_controllen < cmlen) {
                kmsg->msg_flags |= MSG_CTRUNC;
                cmlen = kmsg->msg_controllen;
        }
        cmhdr.cmsg_level = level;
        cmhdr.cmsg_type = type;
        cmhdr.cmsg_len = cmlen;

        if(copy_to_user(cm, &cmhdr, sizeof cmhdr))
                return -EFAULT;
        if(copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
                return -EFAULT;
        cmlen = CMSG_COMPAT_SPACE(len);
        kmsg->msg_control += cmlen;
        kmsg->msg_controllen -= cmlen;
        return 0;
}

void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
{
        struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
        int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
        int fdnum = scm->fp->count;
        struct file **fp = scm->fp->fp;
        int __user *cmfptr;
        int err = 0, i;

        if (fdnum < fdmax)
                fdmax = fdnum;

        for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) {
                int new_fd;
                err = get_unused_fd();
                if (err < 0)
                        break;
                new_fd = err;
                err = put_user(new_fd, cmfptr);
                if (err) {
                        put_unused_fd(new_fd);
                        break;
                }
                /* Bump the usage count and install the file. */
                get_file(fp[i]);
                fd_install(new_fd, fp[i]);
        }

        if (i > 0) {
                int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
                if (!err)
                        err = put_user(SOL_SOCKET, &cm->cmsg_level);
                if (!err)
                        err = put_user(SCM_RIGHTS, &cm->cmsg_type);
                if (!err)
                        err = put_user(cmlen, &cm->cmsg_len);
                if (!err) {
                        cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
                        kmsg->msg_control += cmlen;
                        kmsg->msg_controllen -= cmlen;
                }
        }
        if (i < fdnum)
                kmsg->msg_flags |= MSG_CTRUNC;

        /*
         * All of the files that fit in the message have had their
         * usage counts incremented, so we just free the list.
         */
        __scm_destroy(scm);
}

/*
 * For now, we assume that the compatibility and native version
 * of struct ipt_entry are the same - sfr.  FIXME
 */
struct compat_ipt_replace {
        char                    name[IPT_TABLE_MAXNAMELEN];
        u32                     valid_hooks;
        u32                     num_entries;
        u32                     size;
        u32                     hook_entry[NF_IP_NUMHOOKS];
        u32                     underflow[NF_IP_NUMHOOKS];
        u32                     num_counters;
        compat_uptr_t           counters;       /* struct ipt_counters * */
        struct ipt_entry        entries[0];
};

static int do_netfilter_replace(int fd, int level, int optname,
                                char __user *optval, int optlen)
{
        struct compat_ipt_replace __user *urepl;
        struct ipt_replace __user *repl_nat;
        char name[IPT_TABLE_MAXNAMELEN];
        u32 origsize, tmp32, num_counters;
        unsigned int repl_nat_size;
        int ret;
        int i;
        compat_uptr_t ucntrs;

        urepl = (struct compat_ipt_replace __user *)optval;
        if (get_user(origsize, &urepl->size))
                return -EFAULT;

        /* Hack: Causes ipchains to give correct error msg --RR */
        if (optlen != sizeof(*urepl) + origsize)
                return -ENOPROTOOPT;

        /* XXX Assumes that size of ipt_entry is the same both in
         *     native and compat environments.
         */
        repl_nat_size = sizeof(*repl_nat) + origsize;
        repl_nat = compat_alloc_user_space(repl_nat_size);

        ret = -EFAULT;
        if (put_user(origsize, &repl_nat->size))
                goto out;

        if (!access_ok(VERIFY_READ, urepl, optlen) ||
            !access_ok(VERIFY_WRITE, repl_nat, optlen))
                goto out;

        if (__copy_from_user(name, urepl->name, sizeof(urepl->name)) ||
            __copy_to_user(repl_nat->name, name, sizeof(repl_nat->name)))
                goto out;

        if (__get_user(tmp32, &urepl->valid_hooks) ||
            __put_user(tmp32, &repl_nat->valid_hooks))
                goto out;

        if (__get_user(tmp32, &urepl->num_entries) ||
            __put_user(tmp32, &repl_nat->num_entries))
                goto out;

        if (__get_user(num_counters, &urepl->num_counters) ||
            __put_user(num_counters, &repl_nat->num_counters))
                goto out;

        if (__get_user(ucntrs, &urepl->counters) ||
            __put_user(compat_ptr(ucntrs), &repl_nat->counters))
                goto out;

        if (__copy_in_user(&repl_nat->entries[0],
                           &urepl->entries[0],
                           origsize))
                goto out;

        for (i = 0; i < NF_IP_NUMHOOKS; i++) {
                if (__get_user(tmp32, &urepl->hook_entry[i]) ||
                    __put_user(tmp32, &repl_nat->hook_entry[i]) ||
                    __get_user(tmp32, &urepl->underflow[i]) ||
                    __put_user(tmp32, &repl_nat->underflow[i]))
                        goto out;
        }

        /*
         * Since struct ipt_counters just contains two u_int64_t members
         * we can just do the access_ok check here and pass the (converted)
         * pointer into the standard syscall.  We hope that the pointer is
         * not misaligned ...
         */
        if (!access_ok(VERIFY_WRITE, compat_ptr(ucntrs),
                       num_counters * sizeof(struct ipt_counters)))
                goto out;


        ret = sys_setsockopt(fd, level, optname,
                             (char __user *)repl_nat, repl_nat_size);

out:
        return ret;
}

/*
 * A struct sock_filter is architecture independent.
 */
struct compat_sock_fprog {
        u16             len;
        compat_uptr_t   filter;         /* struct sock_filter * */
};

static int do_set_attach_filter(int fd, int level, int optname,
                                char __user *optval, int optlen)
{
        struct compat_sock_fprog __user *fprog32 = (struct compat_sock_fprog __user *)optval;
        struct sock_fprog __user *kfprog = compat_alloc_user_space(sizeof(struct sock_fprog)); 
        compat_uptr_t ptr;
        u16 len;

        if (!access_ok(VERIFY_READ, fprog32, sizeof(*fprog32)) ||
            !access_ok(VERIFY_WRITE, kfprog, sizeof(struct sock_fprog)) ||
            __get_user(len, &fprog32->len) ||
            __get_user(ptr, &fprog32->filter) ||
            __put_user(len, &kfprog->len) ||
            __put_user(compat_ptr(ptr), &kfprog->filter))
                return -EFAULT;

        return sys_setsockopt(fd, level, optname, (char __user *)kfprog, 
                              sizeof(struct sock_fprog));
}

static int do_set_sock_timeout(int fd, int level, int optname, char __user *optval, int optlen)
{
        struct compat_timeval __user *up = (struct compat_timeval __user *) optval;
        struct timeval ktime;
        mm_segment_t old_fs;
        int err;

        if (optlen < sizeof(*up))
                return -EINVAL;
        if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
            __get_user(ktime.tv_sec, &up->tv_sec) ||
            __get_user(ktime.tv_usec, &up->tv_usec))
                return -EFAULT;
        old_fs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_setsockopt(fd, level, optname, (char *) &ktime, sizeof(ktime));
        set_fs(old_fs);

        return err;
}

asmlinkage long compat_sys_setsockopt(int fd, int level, int optname,
                                char __user *optval, int optlen)
{
        if (optname == IPT_SO_SET_REPLACE)
                return do_netfilter_replace(fd, level, optname,
                                            optval, optlen);
        if (optname == SO_ATTACH_FILTER)
                return do_set_attach_filter(fd, level, optname,
                                            optval, optlen);
        if (optname == SO_RCVTIMEO || optname == SO_SNDTIMEO)
                return do_set_sock_timeout(fd, level, optname, optval, optlen);

        return sys_setsockopt(fd, level, optname, optval, optlen);
}

static int do_get_sock_timeout(int fd, int level, int optname,
                char __user *optval, int __user *optlen)
{
        struct compat_timeval __user *up;
        struct timeval ktime;
        mm_segment_t old_fs;
        int len, err;

        up = (struct compat_timeval __user *) optval;
        if (get_user(len, optlen))
                return -EFAULT;
        if (len < sizeof(*up))
                return -EINVAL;
        len = sizeof(ktime);
        old_fs = get_fs();
        set_fs(KERNEL_DS);
        err = sys_getsockopt(fd, level, optname, (char *) &ktime, &len);
        set_fs(old_fs);

        if (!err) {
                if (put_user(sizeof(*up), optlen) ||
                    !access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
                    __put_user(ktime.tv_sec, &up->tv_sec) ||
                    __put_user(ktime.tv_usec, &up->tv_usec))
                        err = -EFAULT;
        }
        return err;
}

asmlinkage long compat_sys_getsockopt(int fd, int level, int optname,
                                char __user *optval, int __user *optlen)
{
        if (optname == SO_RCVTIMEO || optname == SO_SNDTIMEO)
                return do_get_sock_timeout(fd, level, optname, optval, optlen);
        return sys_getsockopt(fd, level, optname, optval, optlen);
}

/* Argument list sizes for compat_sys_socketcall */
#define AL(x) ((x) * sizeof(u32))
static unsigned char nas[18]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
                                AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
                                AL(6),AL(2),AL(5),AL(5),AL(3),AL(3)};
#undef AL

asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned flags)
{
        return sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}

asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)
{
        return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}

asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
{
        int ret;
        u32 a[6];
        u32 a0, a1;
                                 
        if (call < SYS_SOCKET || call > SYS_RECVMSG)
                return -EINVAL;
        if (copy_from_user(a, args, nas[call]))
                return -EFAULT;
        a0 = a[0];
        a1 = a[1];
        
        switch(call) {
        case SYS_SOCKET:
                ret = sys_socket(a0, a1, a[2]);
                break;
        case SYS_BIND:
                ret = sys_bind(a0, compat_ptr(a1), a[2]);
                break;
        case SYS_CONNECT:
                ret = sys_connect(a0, compat_ptr(a1), a[2]);
                break;
        case SYS_LISTEN:
                ret = sys_listen(a0, a1);
                break;
        case SYS_ACCEPT:
                ret = sys_accept(a0, compat_ptr(a1), compat_ptr(a[2]));
                break;
        case SYS_GETSOCKNAME:
                ret = sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
                break;
        case SYS_GETPEERNAME:
                ret = sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
                break;
        case SYS_SOCKETPAIR:
                ret = sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
                break;
        case SYS_SEND:
                ret = sys_send(a0, compat_ptr(a1), a[2], a[3]);
                break;
        case SYS_SENDTO:
                ret = sys_sendto(a0, compat_ptr(a1), a[2], a[3], compat_ptr(a[4]), a[5]);
                break;
        case SYS_RECV:
                ret = sys_recv(a0, compat_ptr(a1), a[2], a[3]);
                break;
        case SYS_RECVFROM:
                ret = sys_recvfrom(a0, compat_ptr(a1), a[2], a[3], compat_ptr(a[4]), compat_ptr(a[5]));
                break;
        case SYS_SHUTDOWN:
                ret = sys_shutdown(a0,a1);
                break;
        case SYS_SETSOCKOPT:
                ret = compat_sys_setsockopt(a0, a1, a[2],
                                compat_ptr(a[3]), a[4]);
                break;
        case SYS_GETSOCKOPT:
                ret = compat_sys_getsockopt(a0, a1, a[2],
                                compat_ptr(a[3]), compat_ptr(a[4]));
                break;
        case SYS_SENDMSG:
                ret = compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
                break;
        case SYS_RECVMSG:
                ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
                break;
        default:
                ret = -EINVAL;
                break;
        }
        return ret;
}