[src/trunk]: src/lib/libc/gen Prepare for strnvis functionality by providing ...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/127f32cd9131
branches:  trunk
changeset: 763166:127f32cd9131
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Mar 12 03:24:08 2011 +0000

description:
Prepare for strnvis functionality by providing a length to the encoding
functions.

diffstat:

 lib/libc/gen/vis.c |  64 ++++++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 50 insertions(+), 14 deletions(-)

diffs (200 lines):

diff -r d764fb665529 -r 127f32cd9131 lib/libc/gen/vis.c
--- a/lib/libc/gen/vis.c        Sat Mar 12 03:02:58 2011 +0000
+++ b/lib/libc/gen/vis.c        Sat Mar 12 03:24:08 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vis.c,v 1.41 2009/11/23 10:08:47 plunky Exp $  */
+/*     $NetBSD: vis.c,v 1.42 2011/03/12 03:24:08 christos Exp $        */
 
 /*-
  * Copyright (c) 1989, 1993
@@ -57,7 +57,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: vis.c,v 1.41 2009/11/23 10:08:47 plunky Exp $");
+__RCSID("$NetBSD: vis.c,v 1.42 2011/03/12 03:24:08 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #include "namespace.h"
@@ -82,7 +82,7 @@
 #include <stdio.h>
 #include <string.h>
 
-static char *do_svis(char *, int, int, int, const char *);
+static char *do_svis(char *, size_t *, int, int, int, const char *);
 
 #undef BELL
 #define BELL '\a'
@@ -118,7 +118,7 @@
  * This is do_hvis, for HTTP style (RFC 1808)
  */
 static char *
-do_hvis(char *dst, int c, int flag, int nextc, const char *extra)
+do_hvis(char *dst, size_t *len, int c, int flag, int nextc, const char *extra)
 {
 
        if ((isascii(c) && isalnum(c))
@@ -127,8 +127,13 @@
            /* extra */
            || c == '!' || c == '*' || c == '\'' || c == '(' || c == ')'
            || c == ',') {
-               dst = do_svis(dst, c, flag, nextc, extra);
+               dst = do_svis(dst, len, c, flag, nextc, extra);
        } else {
+               if (len) {
+                       if (*len < 3)
+                               return NULL;
+                       *len -= 3;
+               }
                *dst++ = '%';
                *dst++ = xtoa(((unsigned int)c >> 4) & 0xf);
                *dst++ = xtoa((unsigned int)c & 0xf);
@@ -142,7 +147,7 @@
  * NB: No handling of long lines or CRLF.
  */
 static char *
-do_mvis(char *dst, int c, int flag, int nextc, const char *extra)
+do_mvis(char *dst, size_t *len, int c, int flag, int nextc, const char *extra)
 {
        if ((c != '\n') &&
            /* Space at the end of the line */
@@ -151,11 +156,16 @@
            (!isspace(c) && (c < 33 || (c > 60 && c < 62) || c > 126)) ||
            /* Specific char to be escaped */ 
            strchr("#$@[\\]^`{|}~", c) != NULL)) {
+               if (len) {
+                       if (*len < 3)
+                               return NULL;
+                       *len -= 3;
+               }
                *dst++ = '=';
                *dst++ = XTOA(((unsigned int)c >> 4) & 0xf);
                *dst++ = XTOA((unsigned int)c & 0xf);
        } else {
-               dst = do_svis(dst, c, flag, nextc, extra);
+               dst = do_svis(dst, len, c, flag, nextc, extra);
        }
        return dst;
 }
@@ -170,16 +180,27 @@
  *           backslash-protected.
  */
 static char *
-do_svis(char *dst, int c, int flag, int nextc, const char *extra)
+do_svis(char *dst, size_t *len, int c, int flag, int nextc, const char *extra)
 {
        int isextra;
        isextra = strchr(extra, c) != NULL;
+       size_t olen = len ? *len : 0;
+#define HAVE(x) \
+       do { \
+               if (len) { \
+                       if (*len < (x)) \
+                               goto out; \
+                       *len -= (x); \
+               } \
+       } while (/*CONSTCOND*/0)
        if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||
            ((flag & VIS_SAFE) && issafe(c)))) {
+               HAVE(1);
                *dst++ = c;
                return dst;
        }
        if (flag & VIS_CSTYLE) {
+               HAVE(2);
                switch (c) {
                case '\n':
                        *dst++ = '\\'; *dst++ = 'n';
@@ -208,6 +229,7 @@
                case '\0':
                        *dst++ = '\\'; *dst++ = '0';
                        if (isoctal(nextc)) {
+                               HAVE(2);
                                *dst++ = '0';
                                *dst++ = '0';
                        }
@@ -217,32 +239,46 @@
                                *dst++ = '\\'; *dst++ = c;
                                return dst;
                        }
+                       if (len)
+                               *len = olen;
                }
        }
        if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
+               HAVE(4);
                *dst++ = '\\';
                *dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';
                *dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';
                *dst++ =                             (c       & 07) + '0';
        } else {
-               if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\';
+               if ((flag & VIS_NOSLASH) == 0) {
+                       HAVE(1);
+                       *dst++ = '\\';
+               }
+
                if (c & 0200) {
+                       HAVE(1);
                        c &= 0177; *dst++ = 'M';
                }
+
                if (iscntrl(c)) {
+                       HAVE(2);
                        *dst++ = '^';
                        if (c == 0177)
                                *dst++ = '?';
                        else
                                *dst++ = c + '@';
                } else {
+                       HAVE(2);
                        *dst++ = '-'; *dst++ = c;
                }
        }
        return dst;
+out:
+       *len = olen;
+       return NULL;
 }
 
-typedef char *(*visfun_t)(char *, int, int, int, const char *);
+typedef char *(*visfun_t)(char *, size_t *, int, int, int, const char *);
 
 /*
  * Return the appropriate encoding function depending on the flags given.
@@ -275,7 +311,7 @@
                return dst;
        }
        f = getvisfun(flag);
-       dst = (*f)(dst, c, flag, nextc, nextra);
+       dst = (*f)(dst, NULL, c, flag, nextc, nextra);
        free(nextra);
        *dst = '\0';
        return dst;
@@ -316,7 +352,7 @@
        }
        f = getvisfun(flag);
        for (start = dst; (c = *src++) != '\0'; /* empty */)
-               dst = (*f)(dst, c, flag, *src, nextra);
+               dst = (*f)(dst, NULL, c, flag, *src, nextra);
        free(nextra);
        *dst = '\0';
        return (int)(dst - start);
@@ -344,7 +380,7 @@
        f = getvisfun(flag);
        for (start = dst; len > 0; len--) {
                c = *src++;
-               dst = (*f)(dst, c, flag, len > 1 ? *src : '\0', nextra);
+               dst = (*f)(dst, NULL, c, flag, len > 1 ? *src : '\0', nextra);
        }
        free(nextra);
        *dst = '\0';
@@ -371,7 +407,7 @@
                return dst;
        }
        f = getvisfun(flag);
-       dst = (*f)(dst, uc, flag, nextc, extra);
+       dst = (*f)(dst, NULL, uc, flag, nextc, extra);
        free(extra);
        *dst = '\0';
        return dst;