diff options
Diffstat (limited to 'net/compat.c')
-rw-r--r-- | net/compat.c | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/net/compat.c b/net/compat.c new file mode 100644 index 000000000..210fc3b4d --- /dev/null +++ b/net/compat.c @@ -0,0 +1,520 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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/gfp.h> +#include <linux/fs.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/security.h> +#include <linux/audit.h> +#include <linux/export.h> + +#include <net/scm.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <linux/uaccess.h> +#include <net/compat.h> + +int __get_compat_msghdr(struct msghdr *kmsg, + struct compat_msghdr __user *umsg, + struct sockaddr __user **save_addr, + compat_uptr_t *ptr, compat_size_t *len) +{ + struct compat_msghdr msg; + ssize_t err; + + if (copy_from_user(&msg, umsg, sizeof(*umsg))) + return -EFAULT; + + kmsg->msg_flags = msg.msg_flags; + kmsg->msg_namelen = msg.msg_namelen; + + if (!msg.msg_name) + kmsg->msg_namelen = 0; + + if (kmsg->msg_namelen < 0) + return -EINVAL; + + if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) + kmsg->msg_namelen = sizeof(struct sockaddr_storage); + + kmsg->msg_control_is_user = true; + kmsg->msg_control_user = compat_ptr(msg.msg_control); + kmsg->msg_controllen = msg.msg_controllen; + + if (save_addr) + *save_addr = compat_ptr(msg.msg_name); + + if (msg.msg_name && kmsg->msg_namelen) { + if (!save_addr) { + err = move_addr_to_kernel(compat_ptr(msg.msg_name), + kmsg->msg_namelen, + kmsg->msg_name); + if (err < 0) + return err; + } + } else { + kmsg->msg_name = NULL; + kmsg->msg_namelen = 0; + } + + if (msg.msg_iovlen > UIO_MAXIOV) + return -EMSGSIZE; + + kmsg->msg_iocb = NULL; + *ptr = msg.msg_iov; + *len = msg.msg_iovlen; + return 0; +} + +int get_compat_msghdr(struct msghdr *kmsg, + struct compat_msghdr __user *umsg, + struct sockaddr __user **save_addr, + struct iovec **iov) +{ + compat_uptr_t ptr; + compat_size_t len; + ssize_t err; + + err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len); + if (err) + return err; + + err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len, + UIO_FASTIOV, iov, &kmsg->msg_iter); + return err < 0 ? err : 0; +} + +/* Bleech... */ +#define CMSG_COMPAT_ALIGN(len) ALIGN((len), sizeof(s32)) + +#define CMSG_COMPAT_DATA(cmsg) \ + ((void __user *)((char __user *)(cmsg) + sizeof(struct compat_cmsghdr))) +#define CMSG_COMPAT_SPACE(len) \ + (sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len)) +#define CMSG_COMPAT_LEN(len) \ + (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) + +#define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \ + ((ucmlen) >= sizeof(struct compat_cmsghdr) && \ + (ucmlen) <= (unsigned long) \ + ((mhdr)->msg_controllen - \ + ((char __user *)(ucmsg) - (char __user *)(mhdr)->msg_control_user))) + +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, struct sock *sk, + 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; + int err = -EFAULT; + + BUILD_BUG_ON(sizeof(struct compat_cmsghdr) != + CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr))); + + 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_OK(ucmlen, ucmsg, kmsg)) + return -EINVAL; + + tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr)); + tmp = CMSG_ALIGN(tmp); + 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 = sock_kmalloc(sk, kcmlen, GFP_KERNEL); + if (kcmsg == NULL) + return -ENOMEM; + + /* Now copy them over neatly. */ + memset(kcmsg, 0, kcmlen); + ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg); + while (ucmsg != NULL) { + struct compat_cmsghdr cmsg; + if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg))) + goto Efault; + if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg)) + goto Einval; + tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr)); + if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp)) + goto Einval; + kcmsg->cmsg_len = tmp; + kcmsg->cmsg_level = cmsg.cmsg_level; + kcmsg->cmsg_type = cmsg.cmsg_type; + tmp = CMSG_ALIGN(tmp); + if (copy_from_user(CMSG_DATA(kcmsg), + CMSG_COMPAT_DATA(ucmsg), + (cmsg.cmsg_len - sizeof(*ucmsg)))) + goto Efault; + + /* Advance. */ + kcmsg = (struct cmsghdr *)((char *)kcmsg + tmp); + ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len); + } + + /* + * check the length of messages copied in is the same as the + * what we get from the first loop + */ + if ((char *)kcmsg - (char *)kcmsg_base != kcmlen) + goto Einval; + + /* Ok, looks like we made it. Hook it up and return success. */ + kmsg->msg_control = kcmsg_base; + kmsg->msg_controllen = kcmlen; + return 0; + +Einval: + err = -EINVAL; +Efault: + if (kcmsg_base != (struct cmsghdr *)stackbuf) + sock_kfree_s(sk, kcmsg_base, kcmlen); + return err; +} + +int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data) +{ + struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control; + struct compat_cmsghdr cmhdr; + struct old_timeval32 ctv; + struct old_timespec32 cts[3]; + int cmlen; + + if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) { + kmsg->msg_flags |= MSG_CTRUNC; + return 0; /* XXX: return error? check spec. */ + } + + if (!COMPAT_USE_64BIT_TIME) { + if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) { + struct __kernel_old_timeval *tv = (struct __kernel_old_timeval *)data; + ctv.tv_sec = tv->tv_sec; + ctv.tv_usec = tv->tv_usec; + data = &ctv; + len = sizeof(ctv); + } + if (level == SOL_SOCKET && + (type == SO_TIMESTAMPNS_OLD || type == SO_TIMESTAMPING_OLD)) { + int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3; + int i; + struct __kernel_old_timespec *ts = data; + for (i = 0; i < count; i++) { + cts[i].tv_sec = ts[i].tv_sec; + cts[i].tv_nsec = ts[i].tv_nsec; + } + data = &cts; + len = sizeof(cts[0]) * count; + } + } + + 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); + if (kmsg->msg_controllen < cmlen) + cmlen = kmsg->msg_controllen; + kmsg->msg_control += cmlen; + kmsg->msg_controllen -= cmlen; + return 0; +} + +static int scm_max_fds_compat(struct msghdr *msg) +{ + if (msg->msg_controllen <= sizeof(struct compat_cmsghdr)) + return 0; + return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int); +} + +void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) +{ + struct compat_cmsghdr __user *cm = + (struct compat_cmsghdr __user *)msg->msg_control; + unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; + int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count); + int __user *cmsg_data = CMSG_COMPAT_DATA(cm); + int err = 0, i; + + for (i = 0; i < fdmax; i++) { + err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags); + if (err < 0) + break; + } + + if (i > 0) { + int cmlen = CMSG_COMPAT_LEN(i * sizeof(int)); + + 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)); + if (msg->msg_controllen < cmlen) + cmlen = msg->msg_controllen; + msg->msg_control += cmlen; + msg->msg_controllen -= cmlen; + } + } + + if (i < scm->fp->count || (scm->fp->count && fdmax <= 0)) + msg->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); +} + +/* Argument list sizes for compat_sys_socketcall */ +#define AL(x) ((x) * sizeof(u32)) +static unsigned char nas[21] = { + 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), + AL(4), AL(5), AL(4) +}; +#undef AL + +static inline long __compat_sys_sendmsg(int fd, + struct compat_msghdr __user *msg, + unsigned int flags) +{ + return __sys_sendmsg(fd, (struct user_msghdr __user *)msg, + flags | MSG_CMSG_COMPAT, false); +} + +COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg, + unsigned int, flags) +{ + return __compat_sys_sendmsg(fd, msg, flags); +} + +static inline long __compat_sys_sendmmsg(int fd, + struct compat_mmsghdr __user *mmsg, + unsigned int vlen, unsigned int flags) +{ + return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen, + flags | MSG_CMSG_COMPAT, false); +} + +COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg, + unsigned int, vlen, unsigned int, flags) +{ + return __compat_sys_sendmmsg(fd, mmsg, vlen, flags); +} + +static inline long __compat_sys_recvmsg(int fd, + struct compat_msghdr __user *msg, + unsigned int flags) +{ + return __sys_recvmsg(fd, (struct user_msghdr __user *)msg, + flags | MSG_CMSG_COMPAT, false); +} + +COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg, + unsigned int, flags) +{ + return __compat_sys_recvmsg(fd, msg, flags); +} + +static inline long __compat_sys_recvfrom(int fd, void __user *buf, + compat_size_t len, unsigned int flags, + struct sockaddr __user *addr, + int __user *addrlen) +{ + return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr, + addrlen); +} + +COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags) +{ + return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL); +} + +COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len, + unsigned int, flags, struct sockaddr __user *, addr, + int __user *, addrlen) +{ + return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen); +} + +COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg, + unsigned int, vlen, unsigned int, flags, + struct __kernel_timespec __user *, timeout) +{ + return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen, + flags | MSG_CMSG_COMPAT, timeout, NULL); +} + +#ifdef CONFIG_COMPAT_32BIT_TIME +COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg, + unsigned int, vlen, unsigned int, flags, + struct old_timespec32 __user *, timeout) +{ + return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen, + flags | MSG_CMSG_COMPAT, NULL, timeout); +} +#endif + +COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args) +{ + u32 a[AUDITSC_ARGS]; + unsigned int len; + u32 a0, a1; + int ret; + + if (call < SYS_SOCKET || call > SYS_SENDMMSG) + return -EINVAL; + len = nas[call]; + if (len > sizeof(a)) + return -EINVAL; + + if (copy_from_user(a, args, len)) + return -EFAULT; + + ret = audit_socketcall_compat(len / sizeof(a[0]), a); + if (ret) + return ret; + + 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_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0); + 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_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0); + 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 = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3], + NULL, NULL); + break; + case SYS_RECVFROM: + ret = __compat_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 = __sys_setsockopt(a0, a1, a[2], compat_ptr(a[3]), a[4]); + break; + case SYS_GETSOCKOPT: + ret = __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_SENDMMSG: + ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]); + break; + case SYS_RECVMSG: + ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]); + break; + case SYS_RECVMMSG: + ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2], + a[3] | MSG_CMSG_COMPAT, NULL, + compat_ptr(a[4])); + break; + case SYS_ACCEPT4: + ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]); + break; + default: + ret = -EINVAL; + break; + } + return ret; +} |