1 // Copyright 2019 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 // Implementation of sapi::v::Var
16
17 #include "sandboxed_api/var_abstract.h"
18
19 #include <cstddef>
20 #include <cstdint>
21 #include <memory>
22 #include <utility>
23
24 #include "absl/log/log.h"
25 #include "absl/status/status.h"
26 #include "absl/strings/str_cat.h"
27 #include "absl/types/span.h"
28 #include "sandboxed_api/rpcchannel.h"
29 #include "sandboxed_api/sandbox2/util.h"
30 #include "sandboxed_api/util/status_macros.h"
31 #include "sandboxed_api/var_ptr.h"
32
33 namespace sapi::v {
34
operator =(Var && other)35 Var& Var::operator=(Var&& other) {
36 if (this != &other) {
37 using std::swap;
38 swap(local_, other.local_);
39 swap(remote_, other.remote_);
40 swap(free_rpc_channel_, other.free_rpc_channel_);
41 swap(ptr_none_, other.ptr_none_);
42 swap(ptr_both_, other.ptr_both_);
43 swap(ptr_before_, other.ptr_before_);
44 swap(ptr_after_, other.ptr_after_);
45 }
46 return *this;
47 }
48
~Var()49 Var::~Var() {
50 if (free_rpc_channel_ && GetRemote()) {
51 this->Free(free_rpc_channel_).IgnoreError();
52 }
53 }
54
operator ()(Ptr * p)55 void Var::PtrDeleter::operator()(Ptr* p) { delete p; }
56
PtrNone()57 Ptr* Var::PtrNone() {
58 if (!ptr_none_) {
59 ptr_none_.reset(new Ptr(this, kSyncNone));
60 }
61 return ptr_none_.get();
62 }
63
PtrBoth()64 Ptr* Var::PtrBoth() {
65 if (!ptr_both_) {
66 ptr_both_.reset(new Ptr(this, kSyncBoth));
67 }
68 return ptr_both_.get();
69 }
70
PtrBefore()71 Ptr* Var::PtrBefore() {
72 if (!ptr_before_) {
73 ptr_before_.reset(new Ptr(this, kSyncBefore));
74 }
75 return ptr_before_.get();
76 }
77
PtrAfter()78 Ptr* Var::PtrAfter() {
79 if (!ptr_after_) {
80 ptr_after_.reset(new Ptr(this, kSyncAfter));
81 }
82 return ptr_after_.get();
83 }
84
Allocate(RPCChannel * rpc_channel,bool automatic_free)85 absl::Status Var::Allocate(RPCChannel* rpc_channel, bool automatic_free) {
86 void* addr;
87 SAPI_RETURN_IF_ERROR(rpc_channel->Allocate(GetSize(), &addr));
88
89 if (!addr) {
90 LOG(ERROR) << "Allocate: returned nullptr";
91 return absl::UnavailableError("Allocating memory failed");
92 }
93
94 SetRemote(addr);
95 if (automatic_free) {
96 SetFreeRPCChannel(rpc_channel);
97 }
98
99 return absl::OkStatus();
100 }
101
Free(RPCChannel * rpc_channel)102 absl::Status Var::Free(RPCChannel* rpc_channel) {
103 SAPI_RETURN_IF_ERROR(rpc_channel->Free(GetRemote()));
104
105 SetRemote(nullptr);
106 return absl::OkStatus();
107 }
108
TransferToSandboxee(RPCChannel * rpc_channel,pid_t pid)109 absl::Status Var::TransferToSandboxee(RPCChannel* rpc_channel, pid_t pid) {
110 VLOG(3) << "TransferToSandboxee for: " << ToString()
111 << ", local: " << GetLocal() << ", remote: " << GetRemote()
112 << ", size: " << GetSize();
113
114 if (remote_ == nullptr) {
115 LOG(WARNING) << "Object: " << GetTypeString()
116 << " has no remote object set";
117 return absl::FailedPreconditionError(
118 absl::StrCat("Object: ", GetTypeString(), " has no remote object set"));
119 }
120
121 SAPI_ASSIGN_OR_RETURN(
122 size_t ret,
123 sandbox2::util::WriteBytesToPidFrom(
124 pid, reinterpret_cast<uintptr_t>(GetRemote()),
125 absl::MakeSpan(reinterpret_cast<char*>(GetLocal()), GetSize())));
126
127 if (ret != GetSize()) {
128 LOG(WARNING) << "process_vm_writev(pid: " << pid << " laddr: " << GetLocal()
129 << " raddr: " << GetRemote() << " size: " << GetSize() << ")"
130 << " transferred " << ret << " bytes";
131 return absl::UnavailableError("process_vm_writev: partial success");
132 }
133
134 return absl::OkStatus();
135 }
136
TransferFromSandboxee(RPCChannel * rpc_channel,pid_t pid)137 absl::Status Var::TransferFromSandboxee(RPCChannel* rpc_channel, pid_t pid) {
138 VLOG(3) << "TransferFromSandboxee for: " << ToString()
139 << ", local: " << GetLocal() << ", remote: " << GetRemote()
140 << ", size: " << GetSize();
141
142 if (local_ == nullptr) {
143 return absl::FailedPreconditionError(
144 absl::StrCat("Object: ", GetTypeString(), " has no local storage set"));
145 }
146
147 SAPI_ASSIGN_OR_RETURN(
148 size_t ret,
149 sandbox2::util::ReadBytesFromPidInto(
150 pid, reinterpret_cast<uintptr_t>(GetRemote()),
151 absl::MakeSpan(reinterpret_cast<char*>(GetLocal()), GetSize())));
152 if (ret != GetSize()) {
153 LOG(WARNING) << "process_vm_readv(pid: " << pid << " laddr: " << GetLocal()
154 << " raddr: " << GetRemote() << " size: " << GetSize() << ")"
155 << " transferred " << ret << " bytes";
156 return absl::UnavailableError("process_vm_readv succeeded partially");
157 }
158
159 return absl::OkStatus();
160 }
161
162 } // namespace sapi::v
163