整理目录结构，修正当sendmsg()失败时sk_buff泄露的问题

1 files changed, 176 insertions, 0 deletions

diff --git a/util.c b/util.c
new file mode 100644
index 0000000..38b8f48
--- /dev/null
+++ b/util.c
@@ -0,0 +1,176 @@
+/* Modify for kernel module development envorment */
+/* OPENBSD ORIGINAL: lib/libc/net/inet_ntop.c */
+
+#include <linux/in.h>
+
+#ifndef IN6ADDRSZ
+#define IN6ADDRSZ   16   /* IPv6 T_AAAA */                 
+#endif
+
+#ifndef INT16SZ
+#define INT16SZ     2    /* for systems without 16-bit ints */
+#endif
+
+/*
+ * WARNING: Don't even consider trying to compile this on a system where
+ * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
+ */
+
+static const char *inet_ntop4(const u_char *src, char *dst, size_t size);
+static const char *inet_ntop6(const u_char *src, char *dst, size_t size);
+
+/* char *
+ * inet_ntop(af, src, dst, size)
+ *	convert a network format address to presentation format.
+ * return:
+ *	pointer to presentation format address (`dst'), or NULL (see errno).
+ * author:
+ *	Paul Vixie, 1996.
+ */
+const char * inet_ntop(int af, const void *src, char *dst, size_t size)
+{
+    switch (af) {
+    case AF_INET:
+        return (inet_ntop4(src, dst, size));
+    case AF_INET6:
+        return (inet_ntop6(src, dst, size));
+    default:
+        return (NULL);
+    }
+}
+
+/* const char *
+ * inet_ntop4(src, dst, size)
+ *	format an IPv4 address, more or less like inet_ntoa()
+ * return:
+ *	`dst' (as a const)
+ * notes:
+ *	(1) uses no statics
+ *	(2) takes a u_char* not an in_addr as input
+ * author:
+ *	Paul Vixie, 1996.
+ */
+static const char * inet_ntop4(const unsigned char *src, char *dst, size_t size)
+{
+    static const char fmt[] = "%u.%u.%u.%u";
+    char tmp[sizeof "255.255.255.255"];
+    int l;
+
+    l = snprintf(tmp, size, fmt, src[0], src[1], src[2], src[3]);
+    if (l <= 0 || l >= (int)size)
+    {
+        return (NULL);
+    }
+    strlcpy(dst, tmp, size);
+    return (dst);
+}
+
+/* const char *
+ * inet_ntop6(src, dst, size)
+ *	convert IPv6 binary address into presentation (printable) format
+ * author:
+ *	Paul Vixie, 1996.
+ */
+static const char * inet_ntop6(const u_char *src, char *dst, size_t size)
+{
+    /*
+    * Note that int32_t and int16_t need only be "at least" large enough
+    * to contain a value of the specified size.  On some systems, like
+    * Crays, there is no such thing as an integer variable with 16 bits.
+    * Keep this in mind if you think this function should have been coded
+    * to use pointer overlays.  All the world's not a VAX.
+    */
+    char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];
+    char *tp, *ep;
+    struct { int base, len; } best, cur;
+    u_int words[IN6ADDRSZ / INT16SZ];
+    int i;
+    int advance;
+
+    /*
+    * Preprocess:
+    *	Copy the input (bytewise) array into a wordwise array.
+    *	Find the longest run of 0x00's in src[] for :: shorthanding.
+    */
+    memset(words, '\0', sizeof words);
+    for (i = 0; i < IN6ADDRSZ; i++)
+        words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
+    best.base = -1;
+    best.len = 0;
+    cur.base = -1;
+    cur.len = 0;
+    for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
+        if (words[i] == 0) {
+            if (cur.base == -1)
+                cur.base = i, cur.len = 1;
+            else
+                cur.len++;
+        } else {
+            if (cur.base != -1) {
+                if (best.base == -1 || cur.len > best.len)
+                    best = cur;
+                cur.base = -1;
+            }
+        }
+    }
+    if (cur.base != -1) {
+        if (best.base == -1 || cur.len > best.len)
+            best = cur;
+    }
+    if (best.base != -1 && best.len < 2)
+        best.base = -1;
+
+    /*
+    * Format the result.
+    */
+    tp = tmp;
+    ep = tmp + sizeof(tmp);
+    for (i = 0; i < (IN6ADDRSZ / INT16SZ) && tp < ep; i++) {
+        /* Are we inside the best run of 0x00's? */
+        if (best.base != -1 && i >= best.base &&
+            i < (best.base + best.len)) {
+            if (i == best.base) {
+                if (tp + 1 >= ep)
+                    return (NULL);
+                *tp++ = ':';
+            }
+            continue;
+        }
+        /* Are we following an initial run of 0x00s or any real hex? */
+        if (i != 0) {
+            if (tp + 1 >= ep)
+                return (NULL);
+            *tp++ = ':';
+        }
+        /* Is this address an encapsulated IPv4? */
+        if (i == 6 && best.base == 0 &&
+            (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
+            if (!inet_ntop4(src+12, tp, (size_t)(ep - tp)))
+                return (NULL);
+            tp += strlen(tp);
+            break;
+        }
+        advance = snprintf(tp, ep - tp, "%x", words[i]);
+        if (advance <= 0 || advance >= ep - tp)
+            return (NULL);
+        tp += advance;
+    }
+    /* Was it a trailing run of 0x00's? */
+    if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) {
+        if (tp + 1 >= ep)
+            return (NULL);
+        *tp++ = ':';
+    }
+    if (tp + 1 >= ep)
+        return (NULL);
+    *tp++ = '\0';
+
+    /*
+    * Check for overflow, copy, and we're done.
+    */
+    if ((size_t)(tp - tmp) > size) {
+        return (NULL);
+    }
+    strlcpy(dst, tmp, size);
+    return (dst);
+}