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
|
#include "ssh.hh"
#include "finally.hh"
namespace nix {
SSHMaster::SSHMaster(const std::string & host, const std::string & keyFile, const std::string & sshPublicHostKey, bool useMaster, bool compress, int logFD)
: host(host)
, fakeSSH(host == "localhost")
, keyFile(keyFile)
, sshPublicHostKey(sshPublicHostKey)
, useMaster(useMaster && !fakeSSH)
, compress(compress)
, logFD(logFD)
{
if (host == "" || host.starts_with("-"))
throw Error("invalid SSH host name '%s'", host);
auto state(state_.lock());
state->tmpDir = std::make_unique<AutoDelete>(createTempDir("", "nix", true, true, 0700));
}
void SSHMaster::addCommonSSHOpts(Strings & args)
{
auto state(state_.lock());
for (auto & i : tokenizeString<Strings>(getEnv("NIX_SSHOPTS").value_or("")))
args.push_back(i);
if (!keyFile.empty())
args.insert(args.end(), {"-i", keyFile});
if (!sshPublicHostKey.empty()) {
Path fileName = (Path) *state->tmpDir + "/host-key";
auto p = host.rfind("@");
std::string thost = p != std::string::npos ? std::string(host, p + 1) : host;
writeFile(fileName, thost + " " + base64Decode(sshPublicHostKey) + "\n");
args.insert(args.end(), {"-oUserKnownHostsFile=" + fileName});
}
if (compress)
args.push_back("-C");
args.push_back("-oPermitLocalCommand=yes");
args.push_back("-oLocalCommand=echo started");
}
bool SSHMaster::isMasterRunning() {
Strings args = {"-O", "check", host};
addCommonSSHOpts(args);
auto res = runProgram(RunOptions {.program = "ssh", .args = args, .mergeStderrToStdout = true});
return res.first == 0;
}
std::unique_ptr<SSHMaster::Connection> SSHMaster::startCommand(const std::string & command)
{
Path socketPath = startMaster();
Pipe in, out;
in.create();
out.create();
auto conn = std::make_unique<Connection>();
ProcessOptions options;
options.dieWithParent = false;
if (!fakeSSH && !useMaster) {
logger->pause();
}
Finally cleanup = [&]() { logger->resume(); };
conn->sshPid = startProcess([&]() {
restoreProcessContext();
close(in.writeSide.get());
close(out.readSide.get());
if (dup2(in.readSide.get(), STDIN_FILENO) == -1)
throw SysError("duping over stdin");
if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
throw SysError("duping over stdout");
if (logFD != -1 && dup2(logFD, STDERR_FILENO) == -1)
throw SysError("duping over stderr");
Strings args;
if (fakeSSH) {
args = { "bash", "-c" };
} else {
args = { "ssh", host.c_str(), "-x" };
addCommonSSHOpts(args);
if (socketPath != "")
args.insert(args.end(), {"-S", socketPath});
if (verbosity >= lvlChatty)
args.push_back("-v");
}
args.push_back(command);
execvp(args.begin()->c_str(), stringsToCharPtrs(args).data());
// could not exec ssh/bash
throw SysError("unable to execute '%s'", args.front());
}, options);
in.readSide = -1;
out.writeSide = -1;
// Wait for the SSH connection to be established,
// So that we don't overwrite the password prompt with our progress bar.
if (!fakeSSH && !useMaster && !isMasterRunning()) {
std::string reply;
try {
reply = readLine(out.readSide.get());
} catch (EndOfFile & e) { }
if (reply != "started") {
printTalkative("SSH stdout first line: %s", reply);
throw Error("failed to start SSH connection to '%s'", host);
}
}
conn->out = std::move(out.readSide);
conn->in = std::move(in.writeSide);
return conn;
}
Path SSHMaster::startMaster()
{
if (!useMaster) return "";
auto state(state_.lock());
if (state->sshMaster != -1) return state->socketPath;
state->socketPath = (Path) *state->tmpDir + "/ssh.sock";
Pipe out;
out.create();
ProcessOptions options;
options.dieWithParent = false;
logger->pause();
Finally cleanup = [&]() { logger->resume(); };
if (isMasterRunning())
return state->socketPath;
state->sshMaster = startProcess([&]() {
restoreProcessContext();
close(out.readSide.get());
if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
throw SysError("duping over stdout");
Strings args = { "ssh", host.c_str(), "-M", "-N", "-S", state->socketPath };
if (verbosity >= lvlChatty)
args.push_back("-v");
addCommonSSHOpts(args);
execvp(args.begin()->c_str(), stringsToCharPtrs(args).data());
throw SysError("unable to execute '%s'", args.front());
}, options);
out.writeSide = -1;
std::string reply;
try {
reply = readLine(out.readSide.get());
} catch (EndOfFile & e) { }
if (reply != "started") {
printTalkative("SSH master stdout first line: %s", reply);
throw Error("failed to start SSH master connection to '%s'", host);
}
return state->socketPath;
}
}
|
