1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Jeroen Ooms <jeroenooms@gmail.com>
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 * To compile:
24 * gcc crawler.c $(pkg-config --cflags --libs libxml-2.0 libcurl)
25 *
26 */
27 /* <DESC>
28 * Web crawler based on curl and libxml2 to stress-test curl with
29 * hundreds of concurrent connections to various servers.
30 * </DESC>
31 */
32
33 /* Parameters */
34 int max_con = 200;
35 int max_total = 20000;
36 int max_requests = 500;
37 int max_link_per_page = 5;
38 int follow_relative_links = 0;
39 char *start_page = "https://www.reuters.com";
40
41 #include <libxml/HTMLparser.h>
42 #include <libxml/xpath.h>
43 #include <libxml/uri.h>
44 #include <curl/curl.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <math.h>
48 #include <signal.h>
49
50 int pending_interrupt = 0;
sighandler(int dummy)51 void sighandler(int dummy)
52 {
53 pending_interrupt = 1;
54 }
55
56 /* resizable buffer */
57 typedef struct {
58 char *buf;
59 size_t size;
60 } memory;
61
grow_buffer(void * contents,size_t sz,size_t nmemb,void * ctx)62 size_t grow_buffer(void *contents, size_t sz, size_t nmemb, void *ctx)
63 {
64 size_t realsize = sz * nmemb;
65 memory *mem = (memory*) ctx;
66 char *ptr = realloc(mem->buf, mem->size + realsize);
67 if(!ptr) {
68 /* out of memory */
69 printf("not enough memory (realloc returned NULL)\n");
70 return 0;
71 }
72 mem->buf = ptr;
73 memcpy(&(mem->buf[mem->size]), contents, realsize);
74 mem->size += realsize;
75 return realsize;
76 }
77
make_handle(char * url)78 CURL *make_handle(char *url)
79 {
80 CURL *handle = curl_easy_init();
81
82 /* Important: use HTTP2 over HTTPS */
83 curl_easy_setopt(handle, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS);
84 curl_easy_setopt(handle, CURLOPT_URL, url);
85
86 /* buffer body */
87 memory *mem = malloc(sizeof(memory));
88 mem->size = 0;
89 mem->buf = malloc(1);
90 curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, grow_buffer);
91 curl_easy_setopt(handle, CURLOPT_WRITEDATA, mem);
92 curl_easy_setopt(handle, CURLOPT_PRIVATE, mem);
93
94 /* For completeness */
95 curl_easy_setopt(handle, CURLOPT_ACCEPT_ENCODING, "");
96 curl_easy_setopt(handle, CURLOPT_TIMEOUT, 5L);
97 curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1L);
98 /* only allow redirects to HTTP and HTTPS URLs */
99 curl_easy_setopt(handle, CURLOPT_REDIR_PROTOCOLS_STR, "http,https");
100 curl_easy_setopt(handle, CURLOPT_AUTOREFERER, 1L);
101 curl_easy_setopt(handle, CURLOPT_MAXREDIRS, 10L);
102 /* each transfer needs to be done within 20 seconds! */
103 curl_easy_setopt(handle, CURLOPT_TIMEOUT_MS, 20000L);
104 /* connect fast or fail */
105 curl_easy_setopt(handle, CURLOPT_CONNECTTIMEOUT_MS, 2000L);
106 /* skip files larger than a gigabyte */
107 curl_easy_setopt(handle, CURLOPT_MAXFILESIZE_LARGE,
108 (curl_off_t)1024*1024*1024);
109 curl_easy_setopt(handle, CURLOPT_COOKIEFILE, "");
110 curl_easy_setopt(handle, CURLOPT_FILETIME, 1L);
111 curl_easy_setopt(handle, CURLOPT_USERAGENT, "mini crawler");
112 curl_easy_setopt(handle, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
113 curl_easy_setopt(handle, CURLOPT_UNRESTRICTED_AUTH, 1L);
114 curl_easy_setopt(handle, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
115 curl_easy_setopt(handle, CURLOPT_EXPECT_100_TIMEOUT_MS, 0L);
116 return handle;
117 }
118
119 /* HREF finder implemented in libxml2 but could be any HTML parser */
follow_links(CURLM * multi_handle,memory * mem,char * url)120 size_t follow_links(CURLM *multi_handle, memory *mem, char *url)
121 {
122 int opts = HTML_PARSE_NOBLANKS | HTML_PARSE_NOERROR | \
123 HTML_PARSE_NOWARNING | HTML_PARSE_NONET;
124 htmlDocPtr doc = htmlReadMemory(mem->buf, mem->size, url, NULL, opts);
125 if(!doc)
126 return 0;
127 xmlChar *xpath = (xmlChar*) "//a/@href";
128 xmlXPathContextPtr context = xmlXPathNewContext(doc);
129 xmlXPathObjectPtr result = xmlXPathEvalExpression(xpath, context);
130 xmlXPathFreeContext(context);
131 if(!result)
132 return 0;
133 xmlNodeSetPtr nodeset = result->nodesetval;
134 if(xmlXPathNodeSetIsEmpty(nodeset)) {
135 xmlXPathFreeObject(result);
136 return 0;
137 }
138 size_t count = 0;
139 int i;
140 for(i = 0; i < nodeset->nodeNr; i++) {
141 double r = rand();
142 int x = r * nodeset->nodeNr / RAND_MAX;
143 const xmlNode *node = nodeset->nodeTab[x]->xmlChildrenNode;
144 xmlChar *href = xmlNodeListGetString(doc, node, 1);
145 if(follow_relative_links) {
146 xmlChar *orig = href;
147 href = xmlBuildURI(href, (xmlChar *) url);
148 xmlFree(orig);
149 }
150 char *link = (char *) href;
151 if(!link || strlen(link) < 20)
152 continue;
153 if(!strncmp(link, "http://", 7) || !strncmp(link, "https://", 8)) {
154 curl_multi_add_handle(multi_handle, make_handle(link));
155 if(count++ == max_link_per_page)
156 break;
157 }
158 xmlFree(link);
159 }
160 xmlXPathFreeObject(result);
161 return count;
162 }
163
is_html(char * ctype)164 int is_html(char *ctype)
165 {
166 return ctype != NULL && strlen(ctype) > 10 && strstr(ctype, "text/html");
167 }
168
main(void)169 int main(void)
170 {
171 signal(SIGINT, sighandler);
172 LIBXML_TEST_VERSION;
173 curl_global_init(CURL_GLOBAL_DEFAULT);
174 CURLM *multi_handle = curl_multi_init();
175 curl_multi_setopt(multi_handle, CURLMOPT_MAX_TOTAL_CONNECTIONS, max_con);
176 curl_multi_setopt(multi_handle, CURLMOPT_MAX_HOST_CONNECTIONS, 6L);
177
178 /* enables http/2 if available */
179 #ifdef CURLPIPE_MULTIPLEX
180 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
181 #endif
182
183 /* sets html start page */
184 curl_multi_add_handle(multi_handle, make_handle(start_page));
185
186 int msgs_left;
187 int pending = 0;
188 int complete = 0;
189 int still_running = 1;
190 while(still_running && !pending_interrupt) {
191 int numfds;
192 curl_multi_wait(multi_handle, NULL, 0, 1000, &numfds);
193 curl_multi_perform(multi_handle, &still_running);
194
195 /* See how the transfers went */
196 CURLMsg *m = NULL;
197 while((m = curl_multi_info_read(multi_handle, &msgs_left))) {
198 if(m->msg == CURLMSG_DONE) {
199 CURL *handle = m->easy_handle;
200 char *url;
201 memory *mem;
202 curl_easy_getinfo(handle, CURLINFO_PRIVATE, &mem);
203 curl_easy_getinfo(handle, CURLINFO_EFFECTIVE_URL, &url);
204 if(m->data.result == CURLE_OK) {
205 long res_status;
206 curl_easy_getinfo(handle, CURLINFO_RESPONSE_CODE, &res_status);
207 if(res_status == 200) {
208 char *ctype;
209 curl_easy_getinfo(handle, CURLINFO_CONTENT_TYPE, &ctype);
210 printf("[%d] HTTP 200 (%s): %s\n", complete, ctype, url);
211 if(is_html(ctype) && mem->size > 100) {
212 if(pending < max_requests && (complete + pending) < max_total) {
213 pending += follow_links(multi_handle, mem, url);
214 still_running = 1;
215 }
216 }
217 }
218 else {
219 printf("[%d] HTTP %d: %s\n", complete, (int) res_status, url);
220 }
221 }
222 else {
223 printf("[%d] Connection failure: %s\n", complete, url);
224 }
225 curl_multi_remove_handle(multi_handle, handle);
226 curl_easy_cleanup(handle);
227 free(mem->buf);
228 free(mem);
229 complete++;
230 pending--;
231 }
232 }
233 }
234 curl_multi_cleanup(multi_handle);
235 curl_global_cleanup();
236 return 0;
237 }
238
