aboutsummaryrefslogtreecommitdiffstats
path: root/contracts/release/contract.sol
blob: 2a28c58943ac1e84fd6aabca2e14cf0dcb1b6d0c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

// ReleaseOracle is an Ethereum contract to store the current and previous
// versions of the go-ethereum implementation. Its goal is to allow Geth to
// check for new releases automatically without the need to consult a central
// repository.
//
// The contract takes a vote based approach on both assigning authorised signers
// as well as signing off on new Geth releases.
//
// Note, when a signer is demoted, the currently pending release is auto-nuked.
// The reason is to prevent suprises where a demotion actually tilts the votes
// in favor of one voter party and pushing out a new release as a consequence of
// a simple demotion.
contract ReleaseOracle {
  // Votes is an internal data structure to count votes on a specific proposal
  struct Votes {
    address[] pass; // List of signers voting to pass a proposal
    address[] fail; // List of signers voting to fail a proposal
  }

  // Version is the version details of a particular Geth release
  struct Version {
    uint32  major;  // Major version component of the release
    uint32  minor;  // Minor version component of the release
    uint32  patch;  // Patch version component of the release
    bytes20 commit; // Git SHA1 commit hash of the release

    uint64  time;  // Timestamp of the release approval
    Votes   votes; // Votes that passed this release
  }

  // Oracle authorization details
  mapping(address => bool) authorised; // Set of accounts allowed to vote on updating the contract
  address[]                voters;     // List of addresses currently accepted as signers

  // Various proposals being voted on
  mapping(address => Votes) authProps; // Currently running user authorization proposals
  address[]                 authPend;  // List of addresses being voted on (map indexes)

  Version   verProp;  // Currently proposed release being voted on
  Version[] releases; // All the positively voted releases

  // isSigner is a modifier to authorize contract transactions.
  modifier isSigner() {
    if (authorised[msg.sender]) {
      _;
    }
  }

  // Constructor to assign the initial set of signers.
  function ReleaseOracle(address[] signers) {
    // If no signers were specified, assign the creator as the sole signer
    if (signers.length == 0) {
      authorised[msg.sender] = true;
      voters.push(msg.sender);
      return;
    }
    // Otherwise assign the individual signers one by one
    for (uint i = 0; i < signers.length; i++) {
      authorised[signers[i]] = true;
      voters.push(signers[i]);
    }
  }

  // signers is an accessor method to retrieve all the signers (public accessor
  // generates an indexed one, not a retrieve-all version).
  function signers() constant returns(address[]) {
    return voters;
  }

  // authProposals retrieves the list of addresses that authorization proposals
  // are currently being voted on.
  function authProposals() constant returns(address[]) {
    return authPend;
  }

  // authVotes retrieves the current authorization votes for a particular user
  // to promote him into the list of signers, or demote him from there.
  function authVotes(address user) constant returns(address[] promote, address[] demote) {
    return (authProps[user].pass, authProps[user].fail);
  }

  // currentVersion retrieves the semantic version, commit hash and release time
  // of the currently votec active release.
  function currentVersion() constant returns (uint32 major, uint32 minor, uint32 patch, bytes20 commit, uint time) {
    if (releases.length == 0) {
      return (0, 0, 0, 0, 0);
    }
    var release = releases[releases.length - 1];

    return (release.major, release.minor, release.patch, release.commit, release.time);
  }

  // proposedVersion retrieves the semantic version, commit hash and the current
  // votes for the next proposed release.
  function proposedVersion() constant returns (uint32 major, uint32 minor, uint32 patch, bytes20 commit, address[] pass, address[] fail) {
    return (verProp.major, verProp.minor, verProp.patch, verProp.commit, verProp.votes.pass, verProp.votes.fail);
  }

  // promote pitches in on a voting campaign to promote a new user to a signer
  // position.
  function promote(address user) {
    updateSigner(user, true);
  }

  // demote pitches in on a voting campaign to demote an authorised user from
  // its signer position.
  function demote(address user) {
    updateSigner(user, false);
  }

  // release votes for a particular version to be included as the next release.
  function release(uint32 major, uint32 minor, uint32 patch, bytes20 commit) {
    updateRelease(major, minor, patch, commit, true);
  }

  // nuke votes for the currently proposed version to not be included as the next
  // release. Nuking doesn't require a specific version number for simplicity.
  function nuke() {
    updateRelease(0, 0, 0, 0, false);
  }

  // updateSigner marks a vote for changing the status of an Ethereum user, either
  // for or against the user being an authorised signer.
  function updateSigner(address user, bool authorize) internal isSigner {
    // Gather the current votes and ensure we don't double vote
    Votes votes = authProps[user];
    for (uint i = 0; i < votes.pass.length; i++) {
      if (votes.pass[i] == msg.sender) {
        return;
      }
    }
    for (i = 0; i < votes.fail.length; i++) {
      if (votes.fail[i] == msg.sender) {
        return;
      }
    }
    // If no authorization proposal is open, add the user to the index for later lookups
    if (votes.pass.length == 0 && votes.fail.length == 0) {
      authPend.push(user);
    }
    // Cast the vote and return if the proposal cannot be resolved yet
    if (authorize) {
      votes.pass.push(msg.sender);
      if (votes.pass.length <= voters.length / 2) {
        return;
      }
    } else {
      votes.fail.push(msg.sender);
      if (votes.fail.length <= voters.length / 2) {
        return;
      }
    }
    // Proposal resolved in our favor, execute whatever we voted on
    if (authorize && !authorised[user]) {
      authorised[user] = true;
      voters.push(user);
    } else if (!authorize && authorised[user]) {
      authorised[user] = false;

      for (i = 0; i < voters.length; i++) {
        if (voters[i] == user) {
          voters[i] = voters[voters.length - 1];
          voters.length--;

          delete verProp; // Nuke any version proposal (no surprise releases!)
          break;
        }
      }
    }
    // Finally delete the resolved proposal, index and garbage collect
    delete authProps[user];

    for (i = 0; i < authPend.length; i++) {
      if (authPend[i] == user) {
        authPend[i] = authPend[authPend.length - 1];
        authPend.length--;
        break;
      }
    }
  }

  // updateRelease votes for a particular version to be included as the next release,
  // or for the currently proposed release to be nuked out.
  function updateRelease(uint32 major, uint32 minor, uint32 patch, bytes20 commit, bool release) internal isSigner {
    // Skip nuke votes if no proposal is pending
    if (!release && verProp.votes.pass.length == 0) {
      return;
    }
    // Mark a new release if no proposal is pending
    if (verProp.votes.pass.length == 0) {
      verProp.major  = major;
      verProp.minor  = minor;
      verProp.patch  = patch;
      verProp.commit = commit;
    }
    // Make sure positive votes match the current proposal
    if (release && (verProp.major != major || verProp.minor != minor || verProp.patch != patch || verProp.commit != commit)) {
      return;
    }
    // Gather the current votes and ensure we don't double vote
    Votes votes = verProp.votes;
    for (uint i = 0; i < votes.pass.length; i++) {
      if (votes.pass[i] == msg.sender) {
        return;
      }
    }
    for (i = 0; i < votes.fail.length; i++) {
      if (votes.fail[i] == msg.sender) {
        return;
      }
    }
    // Cast the vote and return if the proposal cannot be resolved yet
    if (release) {
      votes.pass.push(msg.sender);
      if (votes.pass.length <= voters.length / 2) {
        return;
      }
    } else {
      votes.fail.push(msg.sender);
      if (votes.fail.length <= voters.length / 2) {
        return;
      }
    }
    // Proposal resolved in our favor, execute whatever we voted on
    if (release) {
      verProp.time = uint64(now);
      releases.push(verProp);
      delete verProp;
    } else {
      delete verProp;
    }
  }
}