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digest.c
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1 /*
2  * Copyright 2015-2020 the Pacemaker project contributors
3  *
4  * The version control history for this file may have further details.
5  *
6  * This source code is licensed under the GNU Lesser General Public License
7  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
8  */
9 
10 #include <crm_internal.h>
11 
12 #include <stdio.h>
13 #include <unistd.h>
14 #include <string.h>
15 #include <stdlib.h>
16 #include <md5.h>
17 
18 #include <crm/crm.h>
19 #include <crm/msg_xml.h>
20 #include <crm/common/xml.h>
21 #include "crmcommon_private.h"
22 
23 #define BEST_EFFORT_STATUS 0
24 
32 static char *
33 dump_xml_for_digest(xmlNode * an_xml_node)
34 {
35  char *buffer = NULL;
36  int offset = 0, max = 0;
37 
38  /* for compatibility with the old result which is used for v1 digests */
39  pcmk__buffer_add_char(&buffer, &offset, &max, ' ');
40  pcmk__xml2text(an_xml_node, 0, &buffer, &offset, &max, 0);
41  pcmk__buffer_add_char(&buffer, &offset, &max, '\n');
42 
43  return buffer;
44 }
45 
56 static char *
57 calculate_xml_digest_v1(xmlNode * input, gboolean sort, gboolean ignored)
58 {
59  char *digest = NULL;
60  char *buffer = NULL;
61  xmlNode *copy = NULL;
62 
63  if (sort) {
64  crm_trace("Sorting xml...");
65  copy = sorted_xml(input, NULL, TRUE);
66  crm_trace("Done");
67  input = copy;
68  }
69 
70  buffer = dump_xml_for_digest(input);
71  CRM_CHECK(buffer != NULL && strlen(buffer) > 0, free_xml(copy);
72  free(buffer);
73  return NULL);
74 
75  digest = crm_md5sum(buffer);
76  crm_log_xml_trace(input, "digest:source");
77 
78  free(buffer);
79  free_xml(copy);
80  return digest;
81 }
82 
91 static char *
92 calculate_xml_digest_v2(xmlNode * source, gboolean do_filter)
93 {
94  char *digest = NULL;
95  char *buffer = NULL;
96  int offset, max;
97 
98  static struct qb_log_callsite *digest_cs = NULL;
99 
100  crm_trace("Begin digest %s", do_filter?"filtered":"");
101  if (do_filter && BEST_EFFORT_STATUS) {
102  /* Exclude the status calculation from the digest
103  *
104  * This doesn't mean it won't be sync'd, we just won't be paranoid
105  * about it being an _exact_ copy
106  *
107  * We don't need it to be exact, since we throw it away and regenerate
108  * from our peers whenever a new DC is elected anyway
109  *
110  * Importantly, this reduces the amount of XML to copy+export as
111  * well as the amount of data for MD5 needs to operate on
112  */
113 
114  } else {
115  pcmk__xml2text(source, (do_filter? xml_log_option_filtered : 0),
116  &buffer, &offset, &max, 0);
117  }
118 
119  CRM_ASSERT(buffer != NULL);
120  digest = crm_md5sum(buffer);
121 
122  if (digest_cs == NULL) {
123  digest_cs = qb_log_callsite_get(__func__, __FILE__, "cib-digest", LOG_TRACE, __LINE__,
125  }
126  if (digest_cs && digest_cs->targets) {
127  char *trace_file = crm_strdup_printf("%s/digest-%s",
128  pcmk__get_tmpdir(), digest);
129 
130  crm_trace("Saving %s.%s.%s to %s",
133  crm_element_value(source, XML_ATTR_NUMUPDATES), trace_file);
134  save_xml_to_file(source, "digest input", trace_file);
135  free(trace_file);
136  }
137 
138  free(buffer);
139  crm_trace("End digest");
140  return digest;
141 }
142 
150 char *
151 calculate_on_disk_digest(xmlNode * input)
152 {
153  /* Always use the v1 format for on-disk digests
154  * a) it's a compatibility nightmare
155  * b) we only use this once at startup, all other
156  * invocations are in a separate child process
157  */
158  return calculate_xml_digest_v1(input, FALSE, FALSE);
159 }
160 
169 char *
170 calculate_operation_digest(xmlNode *input, const char *version)
171 {
172  /* We still need the sorting for operation digests */
173  return calculate_xml_digest_v1(input, TRUE, FALSE);
174 }
175 
186 char *
187 calculate_xml_versioned_digest(xmlNode * input, gboolean sort, gboolean do_filter,
188  const char *version)
189 {
190  /*
191  * @COMPAT digests (on-disk or in diffs/patchsets) created <1.1.4;
192  * removing this affects even full-restart upgrades from old versions
193  *
194  * The sorting associated with v1 digest creation accounted for 23% of
195  * the CIB manager's CPU usage on the server. v2 drops this.
196  *
197  * The filtering accounts for an additional 2.5% and we may want to
198  * remove it in future.
199  *
200  * v2 also uses the xmlBuffer contents directly to avoid additional copying
201  */
202  if (version == NULL || compare_version("3.0.5", version) > 0) {
203  crm_trace("Using v1 digest algorithm for %s", crm_str(version));
204  return calculate_xml_digest_v1(input, sort, do_filter);
205  }
206  crm_trace("Using v2 digest algorithm for %s", crm_str(version));
207  return calculate_xml_digest_v2(input, do_filter);
208 }
209 
219 bool
220 pcmk__verify_digest(xmlNode *input, const char *expected)
221 {
222  char *calculated = NULL;
223  bool passed;
224 
225  if (input != NULL) {
226  calculated = calculate_on_disk_digest(input);
227  if (calculated == NULL) {
228  crm_perror(LOG_ERR, "Could not calculate digest for comparison");
229  return false;
230  }
231  }
232  passed = pcmk__str_eq(expected, calculated, pcmk__str_casei);
233  if (passed) {
234  crm_trace("Digest comparison passed: %s", calculated);
235  } else {
236  crm_err("Digest comparison failed: expected %s, calculated %s",
237  expected, calculated);
238  }
239  free(calculated);
240  return passed;
241 }
242 
251 bool
253 {
254  static const char *filter[] = {
260  };
261 
262  for (int i = 0; i < PCMK__NELEM(filter); i++) {
263  if (strcmp(name, filter[i]) == 0) {
264  return true;
265  }
266  }
267  return false;
268 }
269 
270 char *
271 crm_md5sum(const char *buffer)
272 {
273  int lpc = 0, len = 0;
274  char *digest = NULL;
275  unsigned char raw_digest[MD5_DIGEST_SIZE];
276 
277  if (buffer == NULL) {
278  buffer = "";
279  }
280  len = strlen(buffer);
281 
282  crm_trace("Beginning digest of %d bytes", len);
283  digest = malloc(2 * MD5_DIGEST_SIZE + 1);
284  if (digest) {
285  md5_buffer(buffer, len, raw_digest);
286  for (lpc = 0; lpc < MD5_DIGEST_SIZE; lpc++) {
287  sprintf(digest + (2 * lpc), "%02x", raw_digest[lpc]);
288  }
289  digest[(2 * MD5_DIGEST_SIZE)] = 0;
290  crm_trace("Digest %s.", digest);
291 
292  } else {
293  crm_err("Could not create digest");
294  }
295  return digest;
296 }
#define LOG_TRACE
Definition: logging.h:36
#define CRM_CHECK(expr, failure_action)
Definition: logging.h:218
#define XML_ATTR_UPDATE_ORIG
Definition: msg_xml.h:136
A dumping ground.
#define XML_ATTR_UPDATE_CLIENT
Definition: msg_xml.h:137
#define XML_ATTR_NUMUPDATES
Definition: msg_xml.h:122
G_GNUC_INTERNAL void pcmk__buffer_add_char(char **buffer, int *offset, int *max, char c)
Definition: xml.c:1988
#define XML_ATTR_UPDATE_USER
Definition: msg_xml.h:138
bool pcmk__verify_digest(xmlNode *input, const char *expected)
Definition: digest.c:220
unsigned int crm_trace_nonlog
Definition: logging.c:46
#define XML_ATTR_GENERATION
Definition: msg_xml.h:120
#define XML_ATTR_ORIGIN
Definition: msg_xml.h:124
void * md5_buffer(const char *buffer, size_t len, void *resblock)
Definition: md5.c:227
char * calculate_operation_digest(xmlNode *local_cib, const char *version)
Calculate and return digest of XML operation.
Definition: digest.c:170
const char * crm_element_value(const xmlNode *data, const char *name)
Retrieve the value of an XML attribute.
Definition: nvpair.c:530
#define crm_trace(fmt, args...)
Definition: logging.h:356
char * crm_strdup_printf(char const *format,...) G_GNUC_PRINTF(1
Wrappers for and extensions to libxml2.
#define PCMK__NELEM(a)
Definition: internal.h:38
void free_xml(xmlNode *child)
Definition: xml.c:823
char * calculate_on_disk_digest(xmlNode *local_cib)
Calculate and return digest of XML tree, suitable for storing on disk.
Definition: digest.c:151
xmlNode * sorted_xml(xmlNode *input, xmlNode *parent, gboolean recursive)
Definition: xml.c:2758
G_GNUC_INTERNAL bool pcmk__xa_filterable(const char *name)
Definition: digest.c:252
G_GNUC_INTERNAL void pcmk__xml2text(xmlNode *data, int options, char **buffer, int *offset, int *max, int depth)
Definition: xml.c:1871
#define crm_perror(level, fmt, args...)
Send a system error message to both the log and stderr.
Definition: logging.h:301
#define crm_err(fmt, args...)
Definition: logging.h:350
#define CRM_ASSERT(expr)
Definition: results.h:42
#define XML_CIB_ATTR_WRITTEN
Definition: msg_xml.h:126
const char * pcmk__get_tmpdir(void)
Definition: io.c:540
char * calculate_xml_versioned_digest(xmlNode *input, gboolean sort, gboolean do_filter, const char *version)
Calculate and return digest of XML tree.
Definition: digest.c:187
int compare_version(const char *version1, const char *version2)
Definition: utils.c:232
#define BEST_EFFORT_STATUS
Definition: digest.c:23
#define XML_ATTR_GENERATION_ADMIN
Definition: msg_xml.h:121
#define crm_str(x)
Definition: logging.h:376
void save_xml_to_file(xmlNode *xml, const char *desc, const char *filename)
Definition: xml.c:2055
#define MD5_DIGEST_SIZE
Definition: md5.h:30
#define crm_log_xml_trace(xml, text)
Definition: logging.h:364
char * crm_md5sum(const char *buffer)
Definition: digest.c:271
char * name
Definition: pcmk_fence.c:31
uint32_t version
Definition: remote.c:147