ceph/src/rgw/rgw_etag_verifier.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab ft=cpp
   3
   4 #include "rgw_etag_verifier.h"
   5
   6 #define dout_subsys ceph_subsys_rgw
   7
   8 namespace rgw::putobj {
   9
  10 int create_etag_verifier(const DoutPrefixProvider *dpp,
  11                          CephContext* cct, DataProcessor* filter,
  12                          const bufferlist& manifest_bl,
  13                          const std::optional<RGWCompressionInfo>& compression,
  14                          etag_verifier_ptr& verifier)
  15 {
  16   RGWObjManifest manifest;
  17
  18   try {
  19     auto miter = manifest_bl.cbegin();
  20     decode(manifest, miter);
  21   } catch (buffer::error& err) {
  22     ldpp_dout(dpp, 0) << "ERROR: couldn't decode manifest" << dendl;
  23     return -EIO;
  24   }
  25
  26   RGWObjManifestRule rule;
  27   bool found = manifest.get_rule(0, &rule);
  28   if (!found) {
  29     ldpp_dout(dpp, -1) << "ERROR: manifest->get_rule() could not find rule" << dendl;
  30     return -EIO;
  31   }
  32
  33   if (rule.start_part_num == 0) {
  34     /* Atomic object */
  35     verifier.emplace<ETagVerifier_Atomic>(cct, filter);
  36     return 0;
  37   }
  38
  39   uint64_t cur_part_ofs = UINT64_MAX;
  40   std::vector<uint64_t> part_ofs;
  41
  42   /*
  43    * We must store the offset of each part to calculate the ETAGs for each
  44    * MPU part. These part ETags then become the input for the MPU object
  45    * Etag.
  46    */
  47   for (auto mi = manifest.obj_begin(dpp); mi != manifest.obj_end(dpp); ++mi) {
  48     if (cur_part_ofs == mi.get_part_ofs())
  49       continue;
  50     cur_part_ofs = mi.get_part_ofs();
  51     ldpp_dout(dpp, 20) << "MPU Part offset:" << cur_part_ofs << dendl;
  52     part_ofs.push_back(cur_part_ofs);
  53   }
  54
  55   if (compression) {
  56     // if the source object was compressed, the manifest is storing
  57     // compressed part offsets. transform the compressed offsets back to
  58     // their original offsets by finding the first block of each part
  59     const auto& blocks = compression->blocks;
  60     auto block = blocks.begin();
  61     for (auto& ofs : part_ofs) {
  62       // find the compression_block with new_ofs == ofs
  63       constexpr auto less = [] (const compression_block& block, uint64_t ofs) {
  64         return block.new_ofs < ofs;
  65       };
  66       block = std::lower_bound(block, blocks.end(), ofs, less);
  67       if (block == blocks.end() || block->new_ofs != ofs) {
  68         ldpp_dout(dpp, 4) << "no match for compressed offset " << ofs
  69             << ", disabling etag verification" << dendl;
  70         return -EIO;
  71       }
  72       ofs = block->old_ofs;
  73       ldpp_dout(dpp, 20) << "MPU Part uncompressed offset:" << ofs << dendl;
  74     }
  75   }
  76
  77   verifier.emplace<ETagVerifier_MPU>(cct, std::move(part_ofs), filter);
  78   return 0;
  79 }
  80
  81 int ETagVerifier_Atomic::process(bufferlist&& in, uint64_t logical_offset)
  82 {
  83   bufferlist out;
  84   if (in.length() > 0)
  85     hash.Update((const unsigned char *)in.c_str(), in.length());
  86
  87   return Pipe::process(std::move(in), logical_offset);
  88 }
  89
  90 void ETagVerifier_Atomic::calculate_etag()
  91 {
  92   unsigned char m[CEPH_CRYPTO_MD5_DIGESTSIZE];
  93   char calc_md5[CEPH_CRYPTO_MD5_DIGESTSIZE * 2 + 1];
  94
  95   /* Return early if ETag has already been calculated */
  96   if (!calculated_etag.empty())
  97     return;
  98
  99   hash.Final(m);
 100   buf_to_hex(m, CEPH_CRYPTO_MD5_DIGESTSIZE, calc_md5);
 101   calculated_etag = calc_md5;
 102   ldout(cct, 20) << "Single part object: " << " etag:" << calculated_etag
 103           << dendl;
 104 }
 105
 106 void ETagVerifier_MPU::process_end_of_MPU_part()
 107 {
 108   unsigned char m[CEPH_CRYPTO_MD5_DIGESTSIZE];
 109   char calc_md5_part[CEPH_CRYPTO_MD5_DIGESTSIZE * 2 + 1];
 110   std::string calculated_etag_part;
 111
 112   hash.Final(m);
 113   mpu_etag_hash.Update((const unsigned char *)m, sizeof(m));
 114   hash.Restart();
 115
 116   if (cct->_conf->subsys.should_gather(dout_subsys, 20)) {
 117     buf_to_hex(m, CEPH_CRYPTO_MD5_DIGESTSIZE, calc_md5_part);
 118     calculated_etag_part = calc_md5_part;
 119     ldout(cct, 20) << "Part etag: " << calculated_etag_part << dendl;
 120   }
 121
 122   cur_part_index++;
 123   next_part_index++;
 124 }
 125
 126 int ETagVerifier_MPU::process(bufferlist&& in, uint64_t logical_offset)
 127 {
 128   uint64_t bl_end = in.length() + logical_offset;
 129
 130   /* Handle the last MPU part */
 131   if (size_t(next_part_index) == part_ofs.size()) {
 132     hash.Update((const unsigned char *)in.c_str(), in.length());
 133     goto done;
 134   }
 135
 136   /* Incoming bufferlist spans two MPU parts. Calculate separate ETags */
 137   if (bl_end > part_ofs[next_part_index]) {
 138
 139     uint64_t part_one_len = part_ofs[next_part_index] - logical_offset;
 140     hash.Update((const unsigned char *)in.c_str(), part_one_len);
 141     process_end_of_MPU_part();
 142
 143     hash.Update((const unsigned char *)in.c_str() + part_one_len,
 144       bl_end - part_ofs[cur_part_index]);
 145     /*
 146      * If we've moved to the last part of the MPU, avoid usage of
 147      * parts_ofs[next_part_index] as it will lead to our-of-range access.
 148      */
 149     if (size_t(next_part_index) == part_ofs.size())
 150       goto done;
 151   } else {
 152     hash.Update((const unsigned char *)in.c_str(), in.length());
 153   }
 154
 155   /* Update the MPU Etag if the current part has ended */
 156   if (logical_offset + in.length() + 1 == part_ofs[next_part_index])
 157     process_end_of_MPU_part();
 158
 159 done:
 160   return Pipe::process(std::move(in), logical_offset);
 161 }
 162
 163 void ETagVerifier_MPU::calculate_etag()
 164 {
 165   const uint32_t parts = part_ofs.size();
 166   constexpr auto digits10 = std::numeric_limits<uint32_t>::digits10;
 167   constexpr auto extra = 2 + digits10; // add "-%u\0" at the end
 168
 169   unsigned char m[CEPH_CRYPTO_MD5_DIGESTSIZE], mpu_m[CEPH_CRYPTO_MD5_DIGESTSIZE];
 170   char final_etag_str[CEPH_CRYPTO_MD5_DIGESTSIZE * 2 + extra];
 171
 172   /* Return early if ETag has already been calculated */
 173   if (!calculated_etag.empty())
 174     return;
 175
 176   hash.Final(m);
 177   mpu_etag_hash.Update((const unsigned char *)m, sizeof(m));
 178
 179   /* Refer RGWCompleteMultipart::execute() for ETag calculation for MPU object */
 180   mpu_etag_hash.Final(mpu_m);
 181   buf_to_hex(mpu_m, CEPH_CRYPTO_MD5_DIGESTSIZE, final_etag_str);
 182   snprintf(&final_etag_str[CEPH_CRYPTO_MD5_DIGESTSIZE * 2],
 183            sizeof(final_etag_str) - CEPH_CRYPTO_MD5_DIGESTSIZE * 2,
 184            "-%u", parts);
 185
 186   calculated_etag = final_etag_str;
 187   ldout(cct, 20) << "MPU calculated ETag:" << calculated_etag << dendl;
 188 }
 189
 190 } // namespace rgw::putobj