xref: /third_party/curl/scripts/schemetable.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24#include <stdio.h>
25#include <curl/curl.h>
26
27/*
28 * Use this tool to generate an updated table for the Curl_getn_scheme_handler
29 * function in url.c.
30 */
31
32struct detail {
33  const char *n;
34  const char *ifdef;
35};
36
37static const struct detail scheme[] = {
38  {"dict", "#ifndef CURL_DISABLE_DICT" },
39  {"file", "#ifndef CURL_DISABLE_FILE" },
40  {"ftp", "#ifndef CURL_DISABLE_FTP" },
41  {"ftps", "#if defined(USE_SSL) && !defined(CURL_DISABLE_FTP)" },
42  {"gopher", "#ifndef CURL_DISABLE_GOPHER" },
43  {"gophers", "#if defined(USE_SSL) && !defined(CURL_DISABLE_GOPHER)" },
44  {"http", "#ifndef CURL_DISABLE_HTTP" },
45  {"https", "#if defined(USE_SSL) && !defined(CURL_DISABLE_HTTP)" },
46  {"imap", "#ifndef CURL_DISABLE_IMAP" },
47  {"imaps", "#if defined(USE_SSL) && !defined(CURL_DISABLE_IMAP)" },
48  {"ldap", "#ifndef CURL_DISABLE_LDAP" },
49  {"ldaps", "#if !defined(CURL_DISABLE_LDAP) && \\\n"
50   "  !defined(CURL_DISABLE_LDAPS) && \\\n"
51   "  ((defined(USE_OPENLDAP) && defined(USE_SSL)) || \\\n"
52   "   (!defined(USE_OPENLDAP) && defined(HAVE_LDAP_SSL)))" },
53  {"mqtt", "#ifndef CURL_DISABLE_MQTT" },
54  {"pop3", "#ifndef CURL_DISABLE_POP3" },
55  {"pop3s", "#if defined(USE_SSL) && !defined(CURL_DISABLE_POP3)" },
56  {"rtmp", "#ifdef USE_LIBRTMP" },
57  {"rtmpt", "#ifdef USE_LIBRTMP" },
58  {"rtmpe", "#ifdef USE_LIBRTMP" },
59  {"rtmpte", "#ifdef USE_LIBRTMP" },
60  {"rtmps", "#ifdef USE_LIBRTMP" },
61  {"rtmpts", "#ifdef USE_LIBRTMP" },
62  {"rtsp", "#ifndef CURL_DISABLE_RTSP" },
63  {"scp", "#if defined(USE_SSH) && !defined(USE_WOLFSSH)" },
64  {"sftp", "#if defined(USE_SSH)" },
65  {"smb", "#if !defined(CURL_DISABLE_SMB) && defined(USE_CURL_NTLM_CORE) && \\\n"
66   "  (SIZEOF_CURL_OFF_T > 4)" },
67  {"smbs", "#if defined(USE_SSL) && !defined(CURL_DISABLE_SMB) && \\\n"
68   "  defined(USE_CURL_NTLM_CORE) && (SIZEOF_CURL_OFF_T > 4)" },
69  {"smtp", "#ifndef CURL_DISABLE_SMTP" },
70  {"smtps", "#if defined(USE_SSL) && !defined(CURL_DISABLE_SMTP)" },
71  {"telnet", "#ifndef CURL_DISABLE_TELNET" },
72  {"tftp", "#ifndef CURL_DISABLE_TFTP" },
73  {"ws", "#if defined(USE_WEBSOCKETS) && !defined(CURL_DISABLE_HTTP)" },
74  {"wss", "#if defined(USE_WEBSOCKETS) && \\\n"
75   "  defined(USE_SSL) && !defined(CURL_DISABLE_HTTP)" },
76  { NULL, NULL }
77};
78
79unsigned int calc(const char *s, int add, int shift)
80{
81  const char *so = s;
82  unsigned int c = add;
83  while(*s) {
84    c <<= shift;
85    c += *s;
86    s++;
87  }
88  return c;
89}
90
91unsigned int num[100];
92unsigned int ix[100];
93
94static void showtable(int try, int init, int shift)
95{
96  int nulls = 0;
97  int i;
98  for(i = 0; scheme[i].n; ++i)
99    num[i] = calc(scheme[i].n, init, shift);
100  for(i = 0; scheme[i].n; ++i)
101    ix[i] = num[i] % try;
102  printf("/*\n"
103         "   unsigned int c = %d\n"
104         "   while(l) {\n"
105         "     c <<= %d;\n"
106         "     c += Curl_raw_tolower(*s);\n"
107         "     s++;\n"
108         "     l--;\n"
109         "   }\n"
110         "*/\n", init, shift);
111
112  printf("  static const struct Curl_handler * const protocols[%d] = {", try);
113
114  /* generate table */
115  for(i=0; i < try; i++) {
116    int match = 0;
117    int j;
118    for(j=0; scheme[j].n; j++) {
119      if(ix[j] == i) {
120        printf("\n");
121        printf("%s\n", scheme[j].ifdef);
122        printf("    &Curl_handler_%s,\n", scheme[j].n);
123        printf("#else\n    NULL,\n");
124        printf("#endif");
125        match = 1;
126        nulls = 0;
127        break;
128      }
129    }
130    if(!match) {
131      if(!nulls || (nulls>10)) {
132        printf("\n   ");
133        nulls = 0;
134      }
135      printf(" NULL,", nulls);
136      nulls++;
137    }
138  }
139  printf("\n  };\n");
140}
141
142int main(void)
143{
144  int i;
145  int try;
146  int besttry = 9999;
147  int bestadd = 0;
148  int bestshift = 0;
149  int add;
150  int shift;
151  for(shift = 0; shift < 8; shift++) {
152    for(add = 0; add < 999; add++) {
153      for(i = 0; scheme[i].n; ++i) {
154        unsigned int v = calc(scheme[i].n, add, shift);
155        int j;
156        int badcombo = 0;
157        for(j=0; j < i; j++) {
158
159          if(num[j] == v) {
160            /*
161            printf("NOPE: %u is a dupe (%s and %s)\n",
162                   v, scheme[i], scheme[j]);
163            */
164            badcombo = 1;
165            break;
166          }
167        }
168        if(badcombo)
169          break;
170        num[i] = v;
171      }
172#if 0
173      for(i = 0; scheme[i].n; ++i) {
174        printf("%u - %s\n", num[i], scheme[i].n);
175      }
176#endif
177      /* try different remainders to find smallest possible table */
178      for(try = 28; try < 199; try++) {
179        int good = 1;
180        for(i = 0; scheme[i].n; ++i) {
181          ix[i] = num[i] % try;
182        }
183        /* check for dupes */
184        for(i = 0; scheme[i].n && good; ++i) {
185          int j;
186          for(j=0; j < i; j++) {
187            if(ix[j] == ix[i]) {
188              /* printf("NOPE, try %u causes dupes (%d and %d)\n", try, j, i); */
189              good = 0;
190              break;
191            }
192          }
193        }
194        if(good) {
195          if(try < besttry) {
196            besttry = try;
197            bestadd = add;
198            bestshift = shift;
199          }
200          break;
201        }
202      }
203    }
204  }
205
206  showtable(besttry, bestadd, bestshift);
207}
208