Import of Linux/MIPS 2.1.14

1 files changed, 278 insertions, 0 deletions

diff --git a/net/core/iovec.c b/net/core/iovec.c
new file mode 100644
index 000000000..6db6ac3e9
--- /dev/null
+++ b/net/core/iovec.c
@@ -0,0 +1,278 @@
+/*
+ *	iovec manipulation routines.
+ *
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ *	Fixes:
+ *		Andrew Lunn	:	Errors in iovec copying.
+ *		Pedro Roque	:	Added memcpy_fromiovecend and
+ *					csum_..._fromiovecend.
+ *      Andi Kleen  :   fixed error handling for 2.1
+ */
+
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <asm/uaccess.h>
+#include <asm/byteorder.h>
+#include <asm/checksum.h>
+
+extern inline int min(int x, int y)
+{
+	return x>y?y:x;
+}
+
+
+/*
+ *	Verify iovec
+ *	verify area does a simple check for completly bogus addresses
+ */
+
+int verify_iovec(struct msghdr *m, struct iovec *iov, char *address, int mode)
+{
+	int err=0;
+	int len=0;
+	int ct;
+	
+	if(m->msg_name!=NULL)
+	{
+		if(mode==VERIFY_READ)
+		{
+			err=move_addr_to_kernel(m->msg_name, m->msg_namelen, address);
+		}
+		else
+		{
+			err=verify_area(mode, m->msg_name, m->msg_namelen);
+		}
+		
+		if(err<0)
+			return err;
+		m->msg_name = address;
+	}
+	
+	if(m->msg_control!=NULL)
+	{
+		err=verify_area(mode, m->msg_control, m->msg_controllen);
+		if(err)
+			return err;
+	}
+	
+	for(ct=0;ct<m->msg_iovlen;ct++)
+	{
+		err = copy_from_user(&iov[ct], &m->msg_iov[ct],
+				     sizeof(struct iovec));
+		if (err)
+			return err;
+		
+		err = verify_area(mode, iov[ct].iov_base, iov[ct].iov_len);
+		if(err)
+			return err;
+		len+=iov[ct].iov_len;
+	}
+	m->msg_iov=&iov[0];
+	return len;
+}
+
+/*
+ *	Copy kernel to iovec.
+ */
+ 
+int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
+{
+	int err; 
+	while(len>0)
+	{
+		if(iov->iov_len)
+		{
+			int copy = min(iov->iov_len,len);
+			err = copy_to_user(iov->iov_base,kdata,copy);
+			if (err) 
+			    return err;
+			kdata+=copy;
+			len-=copy;
+			iov->iov_len-=copy;
+			iov->iov_base+=copy;
+		}
+		iov++;
+	}
+	return 0; 
+}
+
+/*
+ *	Copy iovec to kernel.
+ */
+ 
+int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
+{
+	int err; 
+	while(len>0)
+	{
+		if(iov->iov_len)
+		{
+			int copy=min(len,iov->iov_len);
+			err = copy_from_user(kdata, iov->iov_base, copy);
+			if (err)
+			{
+				return err; 
+			}
+			len-=copy;
+			kdata+=copy;
+			iov->iov_base+=copy;
+			iov->iov_len-=copy;
+		}
+		iov++;
+	}
+	return 0; 
+}
+
+
+/*
+ *	For use with ip_build_xmit
+ */
+
+int memcpy_fromiovecend(unsigned char *kdata, struct iovec *iov, int offset,
+			int len)
+{
+	int err; 
+	while(offset>0)
+	{
+		if (offset > iov->iov_len)
+		{
+			offset -= iov->iov_len;
+
+		}
+		else
+		{
+			u8 *base;
+			int copy;
+
+			base = iov->iov_base + offset;
+			copy = min(len, iov->iov_len - offset);
+			offset = 0;
+
+			err = copy_from_user(kdata, base, copy);
+			if (err)
+			{
+				return err;
+			}
+			len-=copy;
+			kdata+=copy;
+		}
+		iov++;
+	}
+
+	while (len>0)
+	{
+		int copy=min(len, iov->iov_len);
+		err = copy_from_user(kdata, iov->iov_base, copy);
+		if (err)
+		{
+			return err;
+		}
+		len-=copy;
+		kdata+=copy;
+		iov++;
+	}
+	return 0;
+}
+
+/*
+ *	And now for the all-in-one: copy and checksum from a user iovec
+ *	directly to a datagram
+ *	Calls to csum_partial but the last must be in 32 bit chunks
+ *
+ *	ip_build_xmit must ensure that when fragmenting only the last
+ *	call to this function will be unaligned also.
+ *
+ *	FIXME: add an error handling path when a copy/checksum from
+ *	user space failed because of a invalid pointer.
+ */
+
+unsigned int csum_partial_copy_fromiovecend(unsigned char *kdata, 
+					    struct iovec *iov, int offset, 
+					    int len, int csum)
+{
+	__u32	partial;
+	__u32	partial_cnt = 0;
+
+	while(offset>0)
+	{
+		if (offset > iov->iov_len)
+		{
+			offset -= iov->iov_len;
+
+		}
+		else
+		{
+			u8 *base;
+			int copy;
+
+			base = iov->iov_base + offset;
+			copy = min(len, iov->iov_len - offset);
+			offset = 0;
+
+			partial_cnt = copy % 4;
+			if (partial_cnt)
+			{
+				copy -= partial_cnt;
+				copy_from_user(&partial, base + copy,
+					       partial_cnt);
+			}
+
+			/*	
+			 *	FIXME: add exception handling to the
+			 *	csum functions and set *err when an
+			 *	exception occurs.
+			 */
+			csum = csum_partial_copy_fromuser(base, kdata, 
+							  copy, csum);
+
+			len   -= copy + partial_cnt;
+			kdata += copy + partial_cnt;
+		}
+		iov++;	
+	}
+
+	while (len>0)
+	{
+		u8 *base = iov->iov_base;
+		int copy=min(len, iov->iov_len);
+		
+		if (partial_cnt)
+		{
+			int par_len = 4 - partial_cnt;
+
+			copy_from_user(&partial, base + partial_cnt, par_len);
+			csum = csum_partial((u8*) &partial, 4, csum);
+			base += par_len;
+			copy -= par_len;
+			partial_cnt = 0;
+		}
+
+		if (len - copy > 0)
+		{
+			partial_cnt = copy % 4;
+			if (partial_cnt)
+			{
+				copy -= partial_cnt;
+				copy_from_user(&partial, base + copy,
+					       partial_cnt);
+			}
+		}
+
+		csum = csum_partial_copy_fromuser(base, kdata, copy, csum);
+		len   -= copy + partial_cnt;
+		kdata += copy + partial_cnt;
+		iov++;
+	}
+
+	return csum;
+}