external/gpl2/lvm2/dist/lib/misc/lvm-string.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
   5  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
   6  *
   7  * This file is part of LVM2.
   8  *
   9  * This copyrighted material is made available to anyone wishing to use,
  10  * modify, copy, or redistribute it subject to the terms and conditions
  11  * of the GNU Lesser General Public License v.2.1.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #include "lib.h"
  19 #include "lvm-string.h"
  20
  21 #include <ctype.h>
  22
  23 int emit_to_buffer(char **buffer, size_t *size, const char *fmt, ...)
  24 {
  25         int n;
  26         va_list ap;
  27
  28         va_start(ap, fmt);
  29         n = vsnprintf(*buffer, *size, fmt, ap);
  30         va_end(ap);
  31
  32         if (n < 0 || ((size_t)n == *size))
  33                 return 0;
  34
  35         *buffer += n;
  36         *size -= n;
  37         return 1;
  38 }
  39
  40 /*
  41  * Count occurences of 'c' in 'str' until we reach a null char.
  42  *
  43  * Returns:
  44  *  len - incremented for each char we encounter.
  45  *  count - number of occurrences of 'c' and 'c2'.
  46  */
  47 static void _count_chars(const char *str, size_t *len, int *count,
  48                          const int c1, const int c2)
  49 {
  50         const char *ptr;
  51
  52         for (ptr = str; *ptr; ptr++, (*len)++)
  53                 if (*ptr == c1 || *ptr == c2)
  54                         (*count)++;
  55 }
  56
  57 /*
  58  * Count occurences of 'c' in 'str' of length 'size'.
  59  *
  60  * Returns:
  61  *   Number of occurrences of 'c'
  62  */
  63 unsigned count_chars(const char *str, size_t len, const int c)
  64 {
  65         size_t i;
  66         unsigned count = 0;
  67
  68         for (i = 0; i < len; i++)
  69                 if (str[i] == c)
  70                         count++;
  71
  72         return count;
  73 }
  74
  75 /*
  76  * Length of string after escaping double quotes and backslashes.
  77  */
  78 size_t escaped_len(const char *str)
  79 {
  80         size_t len = 1;
  81         int count = 0;
  82
  83         _count_chars(str, &len, &count, '\"', '\\');
  84
  85         return count + len;
  86 }
  87
  88 /*
  89  * Copies a string, quoting orig_char with quote_char.
  90  * Optionally also quote quote_char.
  91  */
  92 static void _quote_characters(char **out, const char *src,
  93                               const int orig_char, const int quote_char,
  94                               int quote_quote_char)
  95 {
  96         while (*src) {
  97                 if (*src == orig_char ||
  98                     (*src == quote_char && quote_quote_char))
  99                         *(*out)++ = quote_char;
 100
 101                 *(*out)++ = *src++;
 102         }
 103 }
 104
 105 /*
 106  * Unquote orig_char in string.
 107  * Also unquote quote_char.
 108  */
 109 static void _unquote_characters(char *src, const int orig_char,
 110                                 const int quote_char)
 111 {
 112         char *out = src;
 113
 114         while (*src) {
 115                 if (*src == quote_char &&
 116                     (*(src + 1) == orig_char || *(src + 1) == quote_char))
 117                         src++;
 118
 119                 *out++ = *src++;
 120         }
 121
 122         *out = '\0';
 123 }
 124
 125 /*
 126  * Copies a string, quoting hyphens with hyphens.
 127  */
 128 static void _quote_hyphens(char **out, const char *src)
 129 {
 130         return _quote_characters(out, src, '-', '-', 0);
 131 }
 132
 133 /*
 134  * <vg>-<lv>-<layer> or if !layer just <vg>-<lv>.
 135  */
 136 char *build_dm_name(struct dm_pool *mem, const char *vgname,
 137                     const char *lvname, const char *layer)
 138 {
 139         size_t len = 1;
 140         int hyphens = 1;
 141         char *r, *out;
 142
 143         _count_chars(vgname, &len, &hyphens, '-', 0);
 144         _count_chars(lvname, &len, &hyphens, '-', 0);
 145
 146         if (layer && *layer) {
 147                 _count_chars(layer, &len, &hyphens, '-', 0);
 148                 hyphens++;
 149         }
 150
 151         len += hyphens;
 152
 153         if (!(r = dm_pool_alloc(mem, len))) {
 154                 log_error("build_dm_name: Allocation failed for %" PRIsize_t
 155                           " for %s %s %s.", len, vgname, lvname, layer);
 156                 return NULL;
 157         }
 158
 159         out = r;
 160         _quote_hyphens(&out, vgname);
 161         *out++ = '-';
 162         _quote_hyphens(&out, lvname);
 163
 164         if (layer && *layer) {
 165                 /* No hyphen if the layer begins with _ e.g. _mlog */
 166                 if (*layer != '_')
 167                         *out++ = '-';
 168                 _quote_hyphens(&out, layer);
 169         }
 170         *out = '\0';
 171
 172         return r;
 173 }
 174
 175 /*
 176  * Copies a string, quoting double quotes with backslashes.
 177  */
 178 char *escape_double_quotes(char *out, const char *src)
 179 {
 180         char *buf = out;
 181
 182         _quote_characters(&buf, src, '\"', '\\', 1);
 183         *buf = '\0';
 184
 185         return out;
 186 }
 187
 188 /*
 189  * Undo quoting in situ.
 190  */
 191 void unescape_double_quotes(char *src)
 192 {
 193         _unquote_characters(src, '\"', '\\');
 194 }
 195
 196 /*
 197  * Device layer names are all of the form <vg>-<lv>-<layer>, any
 198  * other hyphens that appear in these names are quoted with yet
 199  * another hyphen.  The top layer of any device has no layer
 200  * name.  eg, vg0-lvol0.
 201  */
 202 int validate_name(const char *n)
 203 {
 204         register char c;
 205         register int len = 0;
 206
 207         if (!n || !*n)
 208                 return 0;
 209
 210         /* Hyphen used as VG-LV separator - ambiguity if LV starts with it */
 211         if (*n == '-')
 212                 return 0;
 213
 214         if (!strcmp(n, ".") || !strcmp(n, ".."))
 215                 return 0;
 216
 217         while ((len++, c = *n++))
 218                 if (!isalnum(c) && c != '.' && c != '_' && c != '-' && c != '+')
 219                         return 0;
 220
 221         if (len > NAME_LEN)
 222                 return 0;
 223
 224         return 1;
 225 }