src/or/consdiff.h

   1 /* Copyright (c) 2014, Daniel Martí
   2  * Copyright (c) 2014, The Tor Project, Inc. */
   3 /* See LICENSE for licensing information */
   4
   5 #ifndef TOR_CONSDIFF_H
   6 #define TOR_CONSDIFF_H
   7
   8 #include "or.h"
   9
  10 char *consensus_diff_generate(const char *cons1,
  11                               const char *cons2);
  12 char *consensus_diff_apply(const char *consensus,
  13                            const char *diff);
  14
  15 int looks_like_a_consensus_diff(const char *document, size_t len);
  16
  17 #ifdef CONSDIFF_PRIVATE
  18 struct memarea_t;
  19
  20 /** Line type used for constructing consensus diffs.  Each of these lines
  21  * refers to a chunk of memory allocated elsewhere, and is not necessarily
  22  * NUL-terminated: this helps us avoid copies and save memory. */
  23 typedef struct cdline_t {
  24   const char *s;
  25   uint32_t len;
  26 } cdline_t;
  27
  28 typedef struct consensus_digest_t {
  29   uint8_t sha3_256[DIGEST256_LEN];
  30 } consensus_digest_t;
  31
  32 STATIC smartlist_t *consdiff_gen_diff(const smartlist_t *cons1,
  33                                       const smartlist_t *cons2,
  34                                       const consensus_digest_t *digests1,
  35                                       const consensus_digest_t *digests2,
  36                                       struct memarea_t *area);
  37 STATIC char *consdiff_apply_diff(const smartlist_t *cons1,
  38                                  const smartlist_t *diff,
  39                                  const consensus_digest_t *digests1);
  40 STATIC int consdiff_get_digests(const smartlist_t *diff,
  41                                 char *digest1_out,
  42                                 char *digest2_out);
  43
  44 /** Data structure to define a slice of a smarltist. */
  45 typedef struct smartlist_slice_t {
  46   /**
  47    * Smartlist that this slice is made from.
  48    * References the whole original smartlist that the slice was made out of.
  49    * */
  50   const smartlist_t *list;
  51   /** Starting position of the slice in the smartlist. */
  52   int offset;
  53   /** Length of the slice, i.e. the number of elements it holds. */
  54   int len;
  55 } smartlist_slice_t;
  56 STATIC smartlist_t *gen_ed_diff(const smartlist_t *cons1,
  57                                 const smartlist_t *cons2,
  58                                 struct memarea_t *area);
  59 STATIC smartlist_t *apply_ed_diff(const smartlist_t *cons1,
  60                                   const smartlist_t *diff,
  61                                   int start_line);
  62 STATIC void calc_changes(smartlist_slice_t *slice1, smartlist_slice_t *slice2,
  63                          bitarray_t *changed1, bitarray_t *changed2);
  64 STATIC smartlist_slice_t *smartlist_slice(const smartlist_t *list,
  65                                           int start, int end);
  66 STATIC int next_router(const smartlist_t *cons, int cur);
  67 STATIC int *lcs_lengths(const smartlist_slice_t *slice1,
  68                         const smartlist_slice_t *slice2,
  69                         int direction);
  70 STATIC void trim_slices(smartlist_slice_t *slice1, smartlist_slice_t *slice2);
  71 STATIC int base64cmp(const cdline_t *hash1, const cdline_t *hash2);
  72 STATIC int get_id_hash(const cdline_t *line, cdline_t *hash_out);
  73 STATIC int is_valid_router_entry(const cdline_t *line);
  74 STATIC int smartlist_slice_string_pos(const smartlist_slice_t *slice,
  75                                       const cdline_t *string);
  76 STATIC void set_changed(bitarray_t *changed1, bitarray_t *changed2,
  77                         const smartlist_slice_t *slice1,
  78                         const smartlist_slice_t *slice2);
  79 STATIC int consensus_split_lines(smartlist_t *out, const char *s,
  80                                  struct memarea_t *area);
  81 STATIC void smartlist_add_linecpy(smartlist_t *lst, struct memarea_t *area,
  82                                   const char *s);
  83 STATIC int lines_eq(const cdline_t *a, const cdline_t *b);
  84 STATIC int line_str_eq(const cdline_t *a, const char *b);
  85
  86 MOCK_DECL(STATIC int,
  87           consensus_compute_digest,(const char *cons,
  88                                     consensus_digest_t *digest_out));
  89 MOCK_DECL(STATIC int,
  90           consensus_compute_digest_as_signed,(const char *cons,
  91                                               consensus_digest_t *digest_out));
  92 MOCK_DECL(STATIC int,
  93           consensus_digest_eq,(const uint8_t *d1,
  94                                const uint8_t *d2));
  95 #endif /* defined(CONSDIFF_PRIVATE) */
  96
  97 #endif /* !defined(TOR_CONSDIFF_H) */
  98