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-rw-r--r--arch/um/include/sysdep-i386/checksum.h219
1 files changed, 219 insertions, 0 deletions
diff --git a/arch/um/include/sysdep-i386/checksum.h b/arch/um/include/sysdep-i386/checksum.h
new file mode 100644
index 000000000000..3a2a45811aa3
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+++ b/arch/um/include/sysdep-i386/checksum.h
@@ -0,0 +1,219 @@
+/*
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_SYSDEP_CHECKSUM_H
+#define __UM_SYSDEP_CHECKSUM_H
+
+#include "linux/in6.h"
+#include "linux/string.h"
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+unsigned int csum_partial(const unsigned char * buff, int len,
+ unsigned int sum);
+
+/*
+ * the same as csum_partial, but copies from src while it
+ * checksums, and handles user-space pointer exceptions correctly, when needed.
+ *
+ * here even more important to align src and dst on a 32-bit (or even
+ * better 64-bit) boundary
+ */
+
+unsigned int csum_partial_copy_to(const unsigned char *src, unsigned char *dst,
+ int len, int sum, int *err_ptr);
+unsigned int csum_partial_copy_from(const unsigned char *src, unsigned char *dst,
+ int len, int sum, int *err_ptr);
+
+/*
+ * Note: when you get a NULL pointer exception here this means someone
+ * passed in an incorrect kernel address to one of these functions.
+ *
+ * If you use these functions directly please don't forget the
+ * access_ok().
+ */
+
+static __inline__
+unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst,
+ int len, int sum)
+{
+ memcpy(dst, src, len);
+ return(csum_partial(dst, len, sum));
+}
+
+static __inline__
+unsigned int csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst,
+ int len, int sum, int *err_ptr)
+{
+ return csum_partial_copy_from(src, dst, len, sum, err_ptr);
+}
+
+/*
+ * These are the old (and unsafe) way of doing checksums, a warning message
+ * will be printed if they are used and an exception occurs.
+ *
+ * these functions should go away after some time.
+ */
+
+#define csum_partial_copy_fromuser csum_partial_copy_from_user
+unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst, int len, int sum);
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ *
+ * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
+ * Arnt Gulbrandsen.
+ */
+static inline unsigned short ip_fast_csum(unsigned char * iph,
+ unsigned int ihl)
+{
+ unsigned int sum;
+
+ __asm__ __volatile__(
+ "movl (%1), %0 ;\n"
+ "subl $4, %2 ;\n"
+ "jbe 2f ;\n"
+ "addl 4(%1), %0 ;\n"
+ "adcl 8(%1), %0 ;\n"
+ "adcl 12(%1), %0 ;\n"
+"1: adcl 16(%1), %0 ;\n"
+ "lea 4(%1), %1 ;\n"
+ "decl %2 ;\n"
+ "jne 1b ;\n"
+ "adcl $0, %0 ;\n"
+ "movl %0, %2 ;\n"
+ "shrl $16, %0 ;\n"
+ "addw %w2, %w0 ;\n"
+ "adcl $0, %0 ;\n"
+ "notl %0 ;\n"
+"2: ;\n"
+ /* Since the input registers which are loaded with iph and ipl
+ are modified, we must also specify them as outputs, or gcc
+ will assume they contain their original values. */
+ : "=r" (sum), "=r" (iph), "=r" (ihl)
+ : "1" (iph), "2" (ihl)
+ : "memory");
+ return(sum);
+}
+
+/*
+ * Fold a partial checksum
+ */
+
+static inline unsigned int csum_fold(unsigned int sum)
+{
+ __asm__(
+ "addl %1, %0 ;\n"
+ "adcl $0xffff, %0 ;\n"
+ : "=r" (sum)
+ : "r" (sum << 16), "0" (sum & 0xffff0000)
+ );
+ return (~sum) >> 16;
+}
+
+static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
+ unsigned long daddr,
+ unsigned short len,
+ unsigned short proto,
+ unsigned int sum)
+{
+ __asm__(
+ "addl %1, %0 ;\n"
+ "adcl %2, %0 ;\n"
+ "adcl %3, %0 ;\n"
+ "adcl $0, %0 ;\n"
+ : "=r" (sum)
+ : "g" (daddr), "g"(saddr), "g"((ntohs(len)<<16)+proto*256), "0"(sum));
+ return sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented
+ */
+static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
+ unsigned long daddr,
+ unsigned short len,
+ unsigned short proto,
+ unsigned int sum)
+{
+ return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
+}
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+
+static inline unsigned short ip_compute_csum(unsigned char * buff, int len)
+{
+ return csum_fold (csum_partial(buff, len, 0));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
+ struct in6_addr *daddr,
+ __u32 len,
+ unsigned short proto,
+ unsigned int sum)
+{
+ __asm__(
+ "addl 0(%1), %0 ;\n"
+ "adcl 4(%1), %0 ;\n"
+ "adcl 8(%1), %0 ;\n"
+ "adcl 12(%1), %0 ;\n"
+ "adcl 0(%2), %0 ;\n"
+ "adcl 4(%2), %0 ;\n"
+ "adcl 8(%2), %0 ;\n"
+ "adcl 12(%2), %0 ;\n"
+ "adcl %3, %0 ;\n"
+ "adcl %4, %0 ;\n"
+ "adcl $0, %0 ;\n"
+ : "=&r" (sum)
+ : "r" (saddr), "r" (daddr),
+ "r"(htonl(len)), "r"(htonl(proto)), "0"(sum));
+
+ return csum_fold(sum);
+}
+
+/*
+ * Copy and checksum to user
+ */
+#define HAVE_CSUM_COPY_USER
+static __inline__ unsigned int csum_and_copy_to_user(const unsigned char *src,
+ unsigned char *dst,
+ int len, int sum, int *err_ptr)
+{
+ if (access_ok(VERIFY_WRITE, dst, len))
+ return(csum_partial_copy_to(src, dst, len, sum, err_ptr));
+
+ if (len)
+ *err_ptr = -EFAULT;
+
+ return -1; /* invalid checksum */
+}
+
+#endif
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only. This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */