no retries or perror if EADDRNOTAVAIL, so can fail gracefully if no net

[unix-history] / usr / src / lib / libc / net / res_comp.c

diff --git a/usr/src/lib/libc/net/res_comp.c b/usr/src/lib/libc/net/res_comp.c
index 1084210..c1a0d9c 100644 (file)
--- a/usr/src/lib/libc/net/res_comp.c
+++ b/usr/src/lib/libc/net/res_comp.c
@@ -1,15 +1,24 @@
+/*
+ * Copyright (c) 1985 Regents of the University of California.
+ * All rights reserved.  The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ */
+

 #ifndef lint
 #ifndef lint

-static char sccsid[] = "@(#)res_comp.c 4.1 (Berkeley) %G%";
-#endif
+static char sccsid[] = "@(#)res_comp.c 5.3 (Berkeley) %G%";
+#endif not lint

 
 #include <sys/types.h>
 #include <stdio.h>
 #include <ctype.h>
 
 #include <sys/types.h>
 #include <stdio.h>
 #include <ctype.h>

-#include <nameser.h>
+#include <arpa/nameser.h>

 
 
 /*
 
 
 /*

- * Expand compressed domain name format to full domain name.
+ * Expand compressed domain name 'comp_dn' to full domain name.
+ * Expanded names are converted to upper case.
+ * 'msg' is a pointer to the begining of the message,
+ * 'exp_dn' is a pointer to a buffer of size 'length' for the result.

  * Return size of compressed name or -1 if there was an error.
  */
 dn_expand(msg, comp_dn, exp_dn, length)
  * Return size of compressed name or -1 if there was an error.
  */
 dn_expand(msg, comp_dn, exp_dn, length)


@@ -19,7 +28,7 @@ dn_expand(msg, comp_dn, exp_dn, length)
        register char *cp, *dn;
        register int n, c;
        char *eom;
        register char *cp, *dn;
        register int n, c;
        char *eom;

-       int len = 0;
+       int len = -1;

 
        dn = exp_dn;
        cp = comp_dn;
 
        dn = exp_dn;
        cp = comp_dn;


@@ -33,19 +42,28 @@ dn_expand(msg, comp_dn, exp_dn, length)
                 */
                switch (n & INDIR_MASK) {
                case 0:
                 */
                switch (n & INDIR_MASK) {
                case 0:

-                       if (dn != exp_dn)
+                       if (dn != exp_dn) {
+                               if (dn >= eom)
+                                       return (-1);

                                *dn++ = '.';
                                *dn++ = '.';

+                       }

                        if (dn+n >= eom)
                                return (-1);
                        while (--n >= 0)
                                if (islower(c = *cp++))
                                        *dn++ = toupper(c);
                        if (dn+n >= eom)
                                return (-1);
                        while (--n >= 0)
                                if (islower(c = *cp++))
                                        *dn++ = toupper(c);

-                               else
+                               else {
+                                       if (c == '.') {
+                                               if (dn+n+1 >= eom)
+                                                       return (-1);
+                                               *dn++ = '\\';
+                                       }

                                        *dn++ = c;
                                        *dn++ = c;

+                               }

                        break;
 
                case INDIR_MASK:
                        break;
 
                case INDIR_MASK:

-                       if (len == 0)
+                       if (len < 0)

                                len = cp - comp_dn + 1;
                        cp = msg + (((n & 0x3f) << 8) | (*cp & 0xff));
                        break;
                                len = cp - comp_dn + 1;
                        cp = msg + (((n & 0x3f) << 8) | (*cp & 0xff));
                        break;


@@ -55,15 +73,22 @@ dn_expand(msg, comp_dn, exp_dn, length)
                }
        }
        *dn = '\0';
                }
        }
        *dn = '\0';

-       if (len == 0)
+       if (len < 0)

                len = cp - comp_dn;
        return (len);
 }
 
 /*
                len = cp - comp_dn;
        return (len);
 }
 
 /*

- * Compress domain name. Return the size of the compressed name or -1.
- * Dnptrs is a list of pointers to previous compressed names. dnptrs[0]
+ * Compress domain name 'exp_dn' into 'comp_dn'.
+ * Return the size of the compressed name or -1.
+ * 'length' is the size of the array pointed to by 'comp_dn'.
+ * 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0]

  * is a pointer to the beginning of the message. The list ends with NULL.
  * is a pointer to the beginning of the message. The list ends with NULL.

+ * 'lastdnptr' is a pointer to the end of the arrary pointed to
+ * by 'dnptrs'. Side effect is to update the list of pointers for
+ * labels inserted into the message as we compress the name.
+ * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
+ * is NULL, we don't update the list.

  */
 dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
        char *exp_dn, *comp_dn;
  */
 dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
        char *exp_dn, *comp_dn;


@@ -108,11 +133,20 @@ dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
                                c = *dn++;
                                break;
                        }
                                c = *dn++;
                                break;
                        }

+                       if (c == '\\') {
+                               if ((c = *dn++) == '\0')
+                                       break;
+                       }

                        if (cp >= eob)
                                return (-1);
                        *cp++ = c;
                } while ((c = *dn++) != '\0');
                        if (cp >= eob)
                                return (-1);
                        *cp++ = c;
                } while ((c = *dn++) != '\0');

-               if ((l = cp - sp - 1) <= 0 || l > MAXLABEL)
+               /* catch trailing '.'s but not '..' */
+               if ((l = cp - sp - 1) == 0 && c == '\0') {
+                       cp--;
+                       break;
+               }
+               if (l <= 0 || l > MAXLABEL)

                        return (-1);
                *sp = l;
        }
                        return (-1);
                *sp = l;
        }


@@ -123,15 +157,15 @@ dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr)
 }
 
 /*
 }
 
 /*

- * Skip over a compressed domain name. Return the size.
+ * Skip over a compressed domain name. Return the size or -1.

  */
  */

-dn_skip(buf)
-       char *buf;
+dn_skip(comp_dn)
+       char *comp_dn;

 {
        register char *cp;
        register int n;
 
 {
        register char *cp;
        register int n;
 

-       cp = buf;
+       cp = comp_dn;

        while (n = *cp++) {
                /*
                 * check for indirection
        while (n = *cp++) {
                /*
                 * check for indirection


@@ -147,7 +181,7 @@ dn_skip(buf)
                }
                break;
        }
                }
                break;
        }

-       return (cp - buf);
+       return (cp - comp_dn);

 }
 
 /*
 }
 
 /*


@@ -171,9 +205,12 @@ dn_find(exp_dn, msg, dnptrs, lastdnptr)
                         */
                        switch (n & INDIR_MASK) {
                        case 0:         /* normal case, n == len */
                         */
                        switch (n & INDIR_MASK) {
                        case 0:         /* normal case, n == len */

-                               while (--n >= 0)
+                               while (--n >= 0) {
+                                       if (*dn == '\\')
+                                               dn++;

                                        if (*dn++ != *cp++)
                                                goto next;
                                        if (*dn++ != *cp++)
                                                goto next;

+                               }

                                if ((n = *dn++) == '\0' && *cp == '\0')
                                        return (sp - msg);
                                if (n == '.')
                                if ((n = *dn++) == '\0' && *cp == '\0')
                                        return (sp - msg);
                                if (n == '.')


@@ -193,3 +230,52 @@ dn_find(exp_dn, msg, dnptrs, lastdnptr)
        }
        return (-1);
 }
        }
        return (-1);
 }

+
+/*
+ * Routines to insert/extract short/long's. Must account for byte
+ * order and non-alignment problems. This code at least has the
+ * advantage of being portable.
+ */
+
+u_short
+getshort(msgp)
+       char *msgp;
+{
+       register u_char *p = (u_char *) msgp;
+
+       return ((*p++ << 8) | *p);
+}
+
+u_long
+getlong(msgp)
+       char *msgp;
+{
+       register u_char *p = (u_char *) msgp;
+       register u_long u;
+
+       u = *p++; u <<= 8;
+       u |= *p++; u <<= 8;
+       u |= *p++; u <<= 8;
+       return (u | *p);
+}
+
+
+putshort(s, msgp)
+       register u_short s;
+       register char *msgp;
+{
+
+       msgp[1] = s;
+       msgp[0] = s >> 8;
+}
+
+putlong(l, msgp)
+       register u_long l;
+       register char *msgp;
+{
+
+       msgp[3] = l;
+       msgp[2] = (l >>= 8);
+       msgp[1] = (l >>= 8);
+       msgp[0] = l >> 8;
+}