lib/xref.c

   1 /*
   2  * Copyright (c) 2017-20  David Lamparter, for NetDEF, Inc.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <stdlib.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24 #include <pthread.h>
  25 #include <signal.h>
  26 #include <inttypes.h>
  27
  28 #include "xref.h"
  29 #include "vty.h"
  30 #include "jhash.h"
  31 #include "sha256.h"
  32 #include "memory.h"
  33 #include "hash.h"
  34
  35 struct xref_block *xref_blocks;
  36 static struct xref_block **xref_block_last = &xref_blocks;
  37
  38 struct xrefdata_uid_head xrefdata_uid = INIT_RBTREE_UNIQ(xrefdata_uid);
  39
  40 static void base32(uint8_t **inpos, int *bitpos,
  41                    char *out, size_t n_chars)
  42 {
  43         static const char base32ch[] = "0123456789ABCDEFGHJKMNPQRSTVWXYZ";
  44
  45         char *opos = out;
  46         uint8_t *in = *inpos;
  47         int bp = *bitpos;
  48
  49         while (opos < out + n_chars) {
  50                 uint32_t bits = in[0] | (in[1] << 8);
  51
  52                 if (bp == -1)
  53                         bits |= 0x10;
  54                 else
  55                         bits >>= bp;
  56
  57                 *opos++ = base32ch[bits & 0x1f];
  58
  59                 bp += 5;
  60                 if (bp >= 8)
  61                         in++, bp -= 8;
  62         }
  63         *opos = '\0';
  64         *inpos = in;
  65         *bitpos = bp;
  66 }
  67
  68 static void xref_add_one(const struct xref *xref)
  69 {
  70         SHA256_CTX sha;
  71         struct xrefdata *xrefdata;
  72
  73         const char *filename, *p, *q;
  74         uint8_t hash[32], *h = hash;
  75         uint32_t be_val;
  76         int bitpos;
  77
  78         if (!xref || !xref->xrefdata)
  79                 return;
  80
  81         xrefdata = xref->xrefdata;
  82         xrefdata->xref = xref;
  83
  84         if (!xrefdata->hashstr)
  85                 return;
  86
  87         /* as far as the unique ID is concerned, only use the last
  88          * directory name + filename, e.g. "bgpd/bgp_route.c".  This
  89          * gives a little leeway in moving things and avoids IDs being
  90          * screwed up by out of tree builds or absolute pathnames.
  91          */
  92         filename = xref->file;
  93         p = strrchr(filename, '/');
  94         if (p) {
  95                 q = memrchr(filename, '/', p - filename);
  96                 if (q)
  97                         filename = q + 1;
  98         }
  99
 100         SHA256_Init(&sha);
 101         SHA256_Update(&sha, filename, strlen(filename));
 102         SHA256_Update(&sha, xrefdata->hashstr,
 103                       strlen(xrefdata->hashstr));
 104         be_val = htonl(xrefdata->hashu32[0]);
 105         SHA256_Update(&sha, &be_val, sizeof(be_val));
 106         be_val = htonl(xrefdata->hashu32[1]);
 107         SHA256_Update(&sha, &be_val, sizeof(be_val));
 108         SHA256_Final(hash, &sha);
 109
 110         bitpos = -1;
 111         base32(&h, &bitpos, &xrefdata->uid[0], 5);
 112         xrefdata->uid[5] = '-';
 113         base32(&h, &bitpos, &xrefdata->uid[6], 5);
 114
 115         xrefdata_uid_add(&xrefdata_uid, xrefdata);
 116 }
 117
 118 void xref_gcc_workaround(const struct xref *xref)
 119 {
 120         xref_add_one(xref);
 121 }
 122
 123 void xref_block_add(struct xref_block *block)
 124 {
 125         const struct xref * const *xrefp;
 126
 127         *xref_block_last = block;
 128         xref_block_last = &block->next;
 129
 130         for (xrefp = block->start; xrefp < block->stop; xrefp++)
 131                 xref_add_one(*xrefp);
 132 }