src/StrList.cc

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 66    HTTP Header Tools */
  10
  11 #include "squid.h"
  12 #include "base/TextException.h"
  13 #include "sbuf/SBuf.h"
  14 #include "SquidString.h"
  15 #include "StrList.h"
  16
  17 void
  18 strListAdd(String &str, const char *item, const size_t itemSize, const char delimiter)
  19 {
  20     if (str.size()) {
  21         const char buf[] = { delimiter, ' ' };
  22         const auto bufSize = sizeof(buf);
  23         Must(str.canGrowBy(bufSize));
  24         str.append(buf, bufSize);
  25     }
  26     Must(str.canGrowBy(itemSize));
  27     str.append(item, itemSize);
  28 }
  29
  30 void
  31 strListAdd(String *str, const char *item, const char delimiter)
  32 {
  33     assert(str);
  34     assert(item);
  35     strListAdd(*str, item, strlen(item), delimiter);
  36 }
  37
  38 void
  39 strListAdd(String &str, const SBuf &item, char delimiter)
  40 {
  41     strListAdd(str, item.rawContent(), item.length(), delimiter);
  42 }
  43
  44 /** returns true iff "m" is a member of the list */
  45 int
  46 strListIsMember(const String * list, const SBuf &m, char del)
  47 {
  48     const char *pos = NULL;
  49     const char *item;
  50     int ilen = 0;
  51
  52     assert(list);
  53     int mlen = m.plength();
  54     while (strListGetItem(list, del, &item, &ilen, &pos)) {
  55         if (mlen == ilen && m.caseCmp(item, ilen) == 0)
  56             return 1;
  57     }
  58     return 0;
  59 }
  60
  61 /** returns true iff "s" is a substring of a member of the list */
  62 int
  63 strListIsSubstr(const String * list, const char *s, char del)
  64 {
  65     assert(list && del);
  66     return (list->find(s) != String::npos);
  67
  68     /** \note
  69      * Note: the original code with a loop is broken because it uses strstr()
  70      * instead of strnstr(). If 's' contains a 'del', strListIsSubstr() may
  71      * return true when it should not. If 's' does not contain a 'del', the
  72      * implementation is equavalent to strstr()! Thus, we replace the loop with
  73      * strstr() above until strnstr() is available.
  74      */
  75 }
  76
  77 /**
  78  * iterates through a 0-terminated string of items separated by 'del's.
  79  * white space around 'del' is considered to be a part of 'del'
  80  * like strtok, but preserves the source, and can iterate several strings at once
  81  *
  82  * returns true if next item is found.
  83  * init pos with NULL to start iteration.
  84  */
  85 int
  86 strListGetItem(const String * str, char del, const char **item, int *ilen, const char **pos)
  87 {
  88     size_t len;
  89     /* ',' is always enabled as field delimiter as this is required for
  90      * processing merged header values properly, even if Cookie normally
  91      * uses ';' as delimiter.
  92      */
  93     static char delim[3][8] = {
  94         "\"?,",
  95         "\"\\",
  96         " ?,\t\r\n"
  97     };
  98     int quoted = 0;
  99     assert(str && item && pos);
 100
 101     delim[0][1] = del;
 102     delim[2][1] = del;
 103
 104     if (!*pos) {
 105         *pos = str->termedBuf();
 106
 107         if (!*pos)
 108             return 0;
 109     }
 110
 111     /* skip leading whitespace and delimiters */
 112     *pos += strspn(*pos, delim[2]);
 113
 114     *item = *pos;       /* remember item's start */
 115
 116     /* find next delimiter */
 117     do {
 118         *pos += strcspn(*pos, delim[quoted]);
 119         if (**pos == '"') {
 120             quoted = !quoted;
 121             *pos += 1;
 122         } else if (quoted && **pos == '\\') {
 123             *pos += 1;
 124             if (**pos)
 125                 *pos += 1;
 126         } else {
 127             break;      /* Delimiter found, marking the end of this value */
 128         }
 129     } while (**pos);
 130
 131     len = *pos - *item;     /* *pos points to del or '\0' */
 132
 133     /* rtrim */
 134     while (len > 0 && xisspace((*item)[len - 1]))
 135         --len;
 136
 137     if (ilen)
 138         *ilen = len;
 139
 140     return len > 0;
 141 }
 142
 143 SBuf
 144 getListMember(const String &list, const char *key, const char delimiter)
 145 {
 146     const char *pos = nullptr;
 147     const char *item = nullptr;
 148     int ilen = 0;
 149     const auto keyLen = strlen(key);
 150     while (strListGetItem(&list, delimiter, &item, &ilen, &pos)) {
 151         if (static_cast<size_t>(ilen) > keyLen && strncmp(item, key, keyLen) == 0 && item[keyLen] == '=')
 152             return SBuf(item + keyLen + 1, ilen - keyLen - 1);
 153     }
 154     return SBuf();
 155 }
 156