| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: url.c,v 1.4 2001/06/22 19:36:18 mdw Exp $ |
| 4 | * |
| 5 | * Parsing and construction of url-encoded name/value pairs |
| 6 | * |
| 7 | * (c) 1999 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of the mLib utilities library. |
| 13 | * |
| 14 | * mLib is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU Library General Public License as |
| 16 | * published by the Free Software Foundation; either version 2 of the |
| 17 | * License, or (at your option) any later version. |
| 18 | * |
| 19 | * mLib is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU Library General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU Library General Public |
| 25 | * License along with mLib; if not, write to the Free |
| 26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 27 | * MA 02111-1307, USA. |
| 28 | */ |
| 29 | |
| 30 | /*----- Revision history --------------------------------------------------* |
| 31 | * |
| 32 | * $Log: url.c,v $ |
| 33 | * Revision 1.4 2001/06/22 19:36:18 mdw |
| 34 | * Include @<ctype.h>@. |
| 35 | * |
| 36 | * Revision 1.3 2001/01/20 12:06:21 mdw |
| 37 | * Be more conservative in base-64 encoding. |
| 38 | * |
| 39 | * Revision 1.2 1999/09/03 08:02:05 mdw |
| 40 | * Make `#' a special character which needs escaping. |
| 41 | * |
| 42 | * Revision 1.1 1999/06/01 09:49:48 mdw |
| 43 | * New files for url-encoding and decoding. |
| 44 | * |
| 45 | */ |
| 46 | |
| 47 | /*----- Header files ------------------------------------------------------*/ |
| 48 | |
| 49 | #include <ctype.h> |
| 50 | #include <stdio.h> |
| 51 | #include <stdlib.h> |
| 52 | #include <string.h> |
| 53 | |
| 54 | #include "dstr.h" |
| 55 | #include "url.h" |
| 56 | |
| 57 | /*----- Main code ---------------------------------------------------------*/ |
| 58 | |
| 59 | /* --- @url_initenc@ --- * |
| 60 | * |
| 61 | * Arguments: @url_ectx *ctx@ = pointer to context block |
| 62 | * |
| 63 | * Returns: --- |
| 64 | * |
| 65 | * Use: Initializes a URL encoding context. |
| 66 | */ |
| 67 | |
| 68 | void url_initenc(url_ectx *ctx) |
| 69 | { |
| 70 | ctx->f = 0; |
| 71 | } |
| 72 | |
| 73 | /* --- @encode@ --- * |
| 74 | * |
| 75 | * Arguments: @dstr *d@ = pointer to output string |
| 76 | * @const char *p@ = pointer to thing to encode |
| 77 | * |
| 78 | * Returns: --- |
| 79 | * |
| 80 | * Use: Encodes the input string into the output string. |
| 81 | */ |
| 82 | |
| 83 | static void encode(dstr *d, const char *p) |
| 84 | { |
| 85 | while (*p) { |
| 86 | switch (*p) { |
| 87 | case ' ': |
| 88 | DPUTC(d, '+'); |
| 89 | break; |
| 90 | default: |
| 91 | if (isalnum((unsigned char)*p)) |
| 92 | DPUTC(d, *p); |
| 93 | else |
| 94 | dstr_putf(d, "%%%02x", *p); |
| 95 | break; |
| 96 | } |
| 97 | p++; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | /* --- @url_enc@ --- * |
| 102 | * |
| 103 | * Arguments: @url_ectx *ctx@ = pointer to encoding context |
| 104 | * @dstr *d@ = pointer to output string |
| 105 | * @const char *name@ = pointer to name |
| 106 | * @const char *value@ = pointer to value |
| 107 | * |
| 108 | * Returns: --- |
| 109 | * |
| 110 | * Use: Writes an assignment between @name@ and @value@ to the |
| 111 | * output string, encoding the values properly. |
| 112 | */ |
| 113 | |
| 114 | void url_enc(url_ectx *ctx, dstr *d, const char *name, const char *value) |
| 115 | { |
| 116 | if (ctx->f & URLF_SEP) |
| 117 | DPUTC(d, '&'); |
| 118 | encode(d, name); |
| 119 | DPUTC(d, '='); |
| 120 | encode(d, value); |
| 121 | DPUTZ(d); |
| 122 | ctx->f |= URLF_SEP; |
| 123 | } |
| 124 | |
| 125 | /* --- @url_initdec@ --- * |
| 126 | * |
| 127 | * Arguments: @url_dctx *ctx@ = pointer to context block |
| 128 | * @const char *p@ = string to read data from |
| 129 | * |
| 130 | * Returns: --- |
| 131 | * |
| 132 | * Use: Initializes a URL decoding context. |
| 133 | */ |
| 134 | |
| 135 | void url_initdec(url_dctx *ctx, const char *p) |
| 136 | { |
| 137 | ctx->p = p; |
| 138 | } |
| 139 | |
| 140 | /* --- @decode@ --- * |
| 141 | * |
| 142 | * Arguments: @dstr *d@ = pointer to output string |
| 143 | * @const char *p@ = pointer to input data |
| 144 | * @int eq@ = whether to stop at `=' characters |
| 145 | * |
| 146 | * Returns: Pointer to next available character. |
| 147 | * |
| 148 | * Use: Does a URL decode. |
| 149 | */ |
| 150 | |
| 151 | static const char *decode(dstr *d, const char *p, int eq) |
| 152 | { |
| 153 | if (!*p) |
| 154 | return (0); |
| 155 | for (;;) { |
| 156 | switch (*p) { |
| 157 | case '=': |
| 158 | if (eq) |
| 159 | return (p); |
| 160 | DPUTC(d, *p); |
| 161 | break; |
| 162 | case 0: |
| 163 | case '&': |
| 164 | return (p); |
| 165 | case '+': |
| 166 | DPUTC(d, ' '); |
| 167 | break; |
| 168 | case '%': { |
| 169 | unsigned int ch; |
| 170 | int n; |
| 171 | int x = sscanf(p + 1, "%2x%n", &ch, &n); |
| 172 | if (x == 1) { |
| 173 | DPUTC(d, ch); |
| 174 | p += n; |
| 175 | break; |
| 176 | } |
| 177 | } |
| 178 | default: |
| 179 | DPUTC(d, *p); |
| 180 | break; |
| 181 | } |
| 182 | p++; |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | /* --- @url_dec@ --- * |
| 187 | * |
| 188 | * Arguments: @url_dctx *ctx@ = pointer to decode context |
| 189 | * @dstr *n@ = pointer to output string for name |
| 190 | * @dstr *v@ = pointer to output string for value |
| 191 | * |
| 192 | * Returns: Nonzero if it read something, zero if there's nothing left |
| 193 | * |
| 194 | * Use: Decodes the next name/value pair from a urlencoded string. |
| 195 | */ |
| 196 | |
| 197 | int url_dec(url_dctx *ctx, dstr *n, dstr *v) |
| 198 | { |
| 199 | const char *p = ctx->p; |
| 200 | size_t l = n->len; |
| 201 | |
| 202 | again: |
| 203 | if ((p = decode(n, p, 1)) == 0 || *p == 0) |
| 204 | return (0); |
| 205 | if (*p != '=') { |
| 206 | p++; |
| 207 | n->len = l; |
| 208 | goto again; |
| 209 | } |
| 210 | p++; |
| 211 | if ((p = decode(v, p, 0)) == 0) |
| 212 | return (0); |
| 213 | DPUTZ(n); |
| 214 | DPUTZ(v); |
| 215 | ctx->p = p; |
| 216 | return (1); |
| 217 | } |
| 218 | |
| 219 | /*----- That's all, folks -------------------------------------------------*/ |