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
--- /dev/null
+++ 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:
+ */