fold verify_iovec() into copy_msghdr_from_user()

... and do the same on the compat side of things.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 51bd666..de52228 100644 (file)
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -322,7 +322,6 @@ extern int csum_partial_copy_fromiovecend(unsigned char *kdata,
 extern unsigned long iov_pages(const struct iovec *iov, int offset,
                               unsigned long nr_segs);
 
-extern int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode);
 extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr);
 extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);
 

diff --git a/include/net/compat.h b/include/net/compat.h
index 3b603b1..42a9c84 100644 (file)
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -40,9 +40,8 @@ int compat_sock_get_timestampns(struct sock *, struct timespec __user *);
 #define compat_mmsghdr mmsghdr
 #endif /* defined(CONFIG_COMPAT) */
 
-int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *);
-int verify_compat_iovec(struct msghdr *, struct iovec *,
-                       struct sockaddr_storage *, int);
+ssize_t get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *,
+                     struct sockaddr __user **, struct iovec **);
 asmlinkage long compat_sys_sendmsg(int, struct compat_msghdr __user *,
                                   unsigned int);
 asmlinkage long compat_sys_sendmmsg(int, struct compat_mmsghdr __user *,

diff --git a/net/compat.c b/net/compat.c
index 7b4b6ad..062f157 100644 (file)
--- a/net/compat.c
+++ b/net/compat.c
@@ -31,14 +31,18 @@
 #include <asm/uaccess.h>
 #include <net/compat.h>
 
-int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
+ssize_t get_compat_msghdr(struct msghdr *kmsg,
+                         struct compat_msghdr __user *umsg,
+                         struct sockaddr __user **save_addr,
+                         struct iovec **iov)
 {
-       compat_uptr_t tmp1, tmp2, tmp3;
+       compat_uptr_t uaddr, uiov, tmp3;
+       ssize_t err;
 
        if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
-           __get_user(tmp1, &umsg->msg_name) ||
+           __get_user(uaddr, &umsg->msg_name) ||
            __get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
-           __get_user(tmp2, &umsg->msg_iov) ||
+           __get_user(uiov, &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) ||
@@ -46,44 +50,32 @@ int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
                return -EFAULT;
        if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
                kmsg->msg_namelen = sizeof(struct sockaddr_storage);
-       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 *iov,
-                  struct sockaddr_storage *kern_address, int mode)
-{
-       struct compat_iovec __user *p;
-       struct iovec *res;
-       int err;
+       if (save_addr)
+               *save_addr = compat_ptr(uaddr);
 
-       if (kern_msg->msg_name && kern_msg->msg_namelen) {
-               if (mode == WRITE) {
-                       int err = move_addr_to_kernel(kern_msg->msg_name,
-                                                     kern_msg->msg_namelen,
-                                                     kern_address);
+       if (uaddr && kmsg->msg_namelen) {
+               if (!save_addr) {
+                       err = move_addr_to_kernel(compat_ptr(uaddr),
+                                                 kmsg->msg_namelen,
+                                                 kmsg->msg_name);
                        if (err < 0)
                                return err;
                }
-               kern_msg->msg_name = kern_address;
        } else {
-               kern_msg->msg_name = NULL;
-               kern_msg->msg_namelen = 0;
+               kmsg->msg_name = NULL;
+               kmsg->msg_namelen = 0;
        }
 
-       if (kern_msg->msg_iovlen > UIO_MAXIOV)
+       if (kmsg->msg_iovlen > UIO_MAXIOV)
                return -EMSGSIZE;
 
-       p = (struct compat_iovec __user *)kern_msg->msg_iov;
-       err = compat_rw_copy_check_uvector(mode, p, kern_msg->msg_iovlen,
-                                          UIO_FASTIOV, iov, &res);
+       err = compat_rw_copy_check_uvector(save_addr ? READ : WRITE,
+                                          compat_ptr(uiov), kmsg->msg_iovlen,
+                                          UIO_FASTIOV, *iov, iov);
        if (err >= 0)
-               kern_msg->msg_iov = res;
-       else if (res != iov)
-               kfree(res);
+               kmsg->msg_iov = *iov;
        return err;
 }
 

diff --git a/net/core/iovec.c b/net/core/iovec.c
index 86beeea..dcbe98b 100644 (file)
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -27,44 +27,6 @@
 #include <net/checksum.h>
 #include <net/sock.h>
 
-/*
- *     Verify iovec. The caller must ensure that the iovec is big enough
- *     to hold the message iovec.
- *
- *     Save time not doing access_ok. copy_*_user will make this work
- *     in any case.
- */
-
-int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode)
-{
-       struct iovec *res;
-       int err;
-
-       if (m->msg_name && m->msg_namelen) {
-               if (mode == WRITE) {
-                       void __user *namep = (void __user __force *)m->msg_name;
-                       int err = move_addr_to_kernel(namep, m->msg_namelen,
-                                                 address);
-                       if (err < 0)
-                               return err;
-               }
-               m->msg_name = address;
-       } else {
-               m->msg_name = NULL;
-               m->msg_namelen = 0;
-       }
-       if (m->msg_iovlen > UIO_MAXIOV)
-               return -EMSGSIZE;
-
-       err = rw_copy_check_uvector(mode, (void __user __force *)m->msg_iov,
-                                   m->msg_iovlen, UIO_FASTIOV, iov, &res);
-       if (err >= 0)
-               m->msg_iov = res;
-       else if (res != iov)
-               kfree(res);
-       return err;
-}
-
 /*
  *     And now for the all-in-one: copy and checksum from a user iovec
  *     directly to a datagram

diff --git a/net/socket.c b/net/socket.c
index 59020f0..ee3ee39 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -1988,16 +1988,26 @@ struct used_address {
        unsigned int name_len;
 };
 
-static int copy_msghdr_from_user(struct msghdr *kmsg,
-                                struct user_msghdr __user *umsg)
+static ssize_t copy_msghdr_from_user(struct msghdr *kmsg,
+                                    struct user_msghdr __user *umsg,
+                                    struct sockaddr __user **save_addr,
+                                    struct iovec **iov)
 {
-       /* We are relying on the (currently) identical layouts.  Once
-        * the kernel-side changes, this place will need to be updated
-        */
-       if (copy_from_user(kmsg, umsg, sizeof(struct msghdr)))
+       struct sockaddr __user *uaddr;
+       struct iovec __user *uiov;
+       ssize_t err;
+
+       if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
+           __get_user(uaddr, &umsg->msg_name) ||
+           __get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
+           __get_user(uiov, &umsg->msg_iov) ||
+           __get_user(kmsg->msg_iovlen, &umsg->msg_iovlen) ||
+           __get_user(kmsg->msg_control, &umsg->msg_control) ||
+           __get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
+           __get_user(kmsg->msg_flags, &umsg->msg_flags))
                return -EFAULT;
 
-       if (kmsg->msg_name == NULL)
+       if (!uaddr)
                kmsg->msg_namelen = 0;
 
        if (kmsg->msg_namelen < 0)
@@ -2005,7 +2015,31 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
 
        if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
                kmsg->msg_namelen = sizeof(struct sockaddr_storage);
-       return 0;
+
+       if (save_addr)
+               *save_addr = uaddr;
+
+       if (uaddr && kmsg->msg_namelen) {
+               if (!save_addr) {
+                       err = move_addr_to_kernel(uaddr, kmsg->msg_namelen,
+                                                 kmsg->msg_name);
+                       if (err < 0)
+                               return err;
+               }
+       } else {
+               kmsg->msg_name = NULL;
+               kmsg->msg_namelen = 0;
+       }
+
+       if (kmsg->msg_iovlen > UIO_MAXIOV)
+               return -EMSGSIZE;
+
+       err = rw_copy_check_uvector(save_addr ? READ : WRITE,
+                                   uiov, kmsg->msg_iovlen,
+                                   UIO_FASTIOV, *iov, iov);
+       if (err >= 0)
+               kmsg->msg_iov = *iov;
+       return err;
 }
 
 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
@@ -2020,26 +2054,17 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
            __attribute__ ((aligned(sizeof(__kernel_size_t))));
        /* 20 is size of ipv6_pktinfo */
        unsigned char *ctl_buf = ctl;
-       int err, ctl_len, total_len;
+       int ctl_len, total_len;
+       ssize_t err;
 
-       err = -EFAULT;
-       if (MSG_CMSG_COMPAT & flags) {
-               if (get_compat_msghdr(msg_sys, msg_compat))
-                       return -EFAULT;
-       } else {
-               err = copy_msghdr_from_user(msg_sys, msg);
-               if (err)
-                       return err;
-       }
+       msg_sys->msg_name = &address;
 
-       /* This will also move the address data into kernel space */
        if (MSG_CMSG_COMPAT & flags)
-               err = verify_compat_iovec(msg_sys, iovstack, &address, WRITE);
+               err = get_compat_msghdr(msg_sys, msg_compat, NULL, &iov);
        else
-               err = verify_iovec(msg_sys, iovstack, &address, WRITE);
+               err = copy_msghdr_from_user(msg_sys, msg, NULL, &iov);
        if (err < 0)
                goto out_freeiov;
-       iov = msg_sys->msg_iov;
        total_len = err;
 
        err = -ENOBUFS;
@@ -2215,36 +2240,24 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
        struct iovec iovstack[UIO_FASTIOV];
        struct iovec *iov = iovstack;
        unsigned long cmsg_ptr;
-       int err, total_len, len;
+       int total_len, len;
+       ssize_t err;
 
        /* kernel mode address */
        struct sockaddr_storage addr;
 
        /* user mode address pointers */
        struct sockaddr __user *uaddr;
-       int __user *uaddr_len;
+       int __user *uaddr_len = COMPAT_NAMELEN(msg);
 
-       if (MSG_CMSG_COMPAT & flags) {
-               if (get_compat_msghdr(msg_sys, msg_compat))
-                       return -EFAULT;
-       } else {
-               err = copy_msghdr_from_user(msg_sys, msg);
-               if (err)
-                       return err;
-       }
+       msg_sys->msg_name = &addr;
 
-       /* Save the user-mode address (verify_iovec will change the
-        * kernel msghdr to use the kernel address space)
-        */
-       uaddr = (__force void __user *)msg_sys->msg_name;
-       uaddr_len = COMPAT_NAMELEN(msg);
        if (MSG_CMSG_COMPAT & flags)
-               err = verify_compat_iovec(msg_sys, iovstack, &addr, READ);
+               err = get_compat_msghdr(msg_sys, msg_compat, &uaddr, &iov);
        else
-               err = verify_iovec(msg_sys, iovstack, &addr, READ);
+               err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov);
        if (err < 0)
                goto out_freeiov;
-       iov = msg_sys->msg_iov;
        total_len = err;
 
        cmsg_ptr = (unsigned long)msg_sys->msg_control;