aboutsummaryrefslogtreecommitdiffstats
path: root/plumbing/transport/http/common.go
blob: 10a267a653cdd3e9914210620cf2c3b7d5b2ed79 (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
// Package http implements the HTTP transport protocol.
package http

import (
	"bytes"
	"fmt"
	"net/http"
	"strconv"

	"gopkg.in/src-d/go-git.v4/plumbing"
	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
	"gopkg.in/src-d/go-git.v4/plumbing/transport"
)

// it requires a bytes.Buffer, because we need to know the length
func applyHeadersToRequest(req *http.Request, content *bytes.Buffer, host string, requestType string) {
	req.Header.Add("User-Agent", "git/1.0")
	req.Header.Add("Host", host) // host:port

	if content == nil {
		req.Header.Add("Accept", "*/*")
		return
	}

	req.Header.Add("Accept", fmt.Sprintf("application/x-%s-result", requestType))
	req.Header.Add("Content-Type", fmt.Sprintf("application/x-%s-request", requestType))
	req.Header.Add("Content-Length", strconv.Itoa(content.Len()))
}

func advertisedReferences(s *session, serviceName string) (*packp.AdvRefs, error) {
	url := fmt.Sprintf(
		"%s/info/refs?service=%s",
		s.endpoint.String(), serviceName,
	)

	req, err := http.NewRequest(http.MethodGet, url, nil)
	if err != nil {
		return nil, err
	}

	s.applyAuthToRequest(req)
	applyHeadersToRequest(req, nil, s.endpoint.Host, serviceName)
	res, err := s.client.Do(req)
	if err != nil {
		return nil, err
	}

	if err := NewErr(res); err != nil {
		_ = res.Body.Close()
		return nil, err
	}

	ar := packp.NewAdvRefs()
	if err := ar.Decode(res.Body); err != nil {
		if err == packp.ErrEmptyAdvRefs {
			err = transport.ErrEmptyRemoteRepository
		}

		return nil, err
	}

	transport.FilterUnsupportedCapabilities(ar.Capabilities)
	s.advRefs = ar

	return ar, nil
}

type client struct {
	c *http.Client
}

// DefaultClient is the default HTTP client, which uses `http.DefaultClient`.
var DefaultClient = NewClient(nil)

// NewClient creates a new client with a custom net/http client.
// See `InstallProtocol` to install and override default http client.
// Unless a properly initialized client is given, it will fall back into
// `http.DefaultClient`.
//
// Note that for HTTP client cannot distinguist between private repositories and
// unexistent repositories on GitHub. So it returns `ErrAuthorizationRequired`
// for both.
func NewClient(c *http.Client) transport.Transport {
	if c == nil {
		return &client{http.DefaultClient}
	}

	return &client{
		c: c,
	}
}

func (c *client) NewUploadPackSession(ep *transport.Endpoint, auth transport.AuthMethod) (
	transport.UploadPackSession, error) {

	return newUploadPackSession(c.c, ep, auth)
}

func (c *client) NewReceivePackSession(ep *transport.Endpoint, auth transport.AuthMethod) (
	transport.ReceivePackSession, error) {

	return newReceivePackSession(c.c, ep, auth)
}

type session struct {
	auth     AuthMethod
	client   *http.Client
	endpoint *transport.Endpoint
	advRefs  *packp.AdvRefs
}

func newSession(c *http.Client, ep *transport.Endpoint, auth transport.AuthMethod) (*session, error) {
	s := &session{
		auth:     basicAuthFromEndpoint(ep),
		client:   c,
		endpoint: ep,
	}
	if auth != nil {
		a, ok := auth.(AuthMethod)
		if !ok {
			return nil, transport.ErrInvalidAuthMethod
		}

		s.auth = a
	}

	return s, nil
}

func (*session) Close() error {
	return nil
}

func (s *session) applyAuthToRequest(req *http.Request) {
	if s.auth == nil {
		return
	}

	s.auth.setAuth(req)
}

// AuthMethod is concrete implementation of common.AuthMethod for HTTP services
type AuthMethod interface {
	transport.AuthMethod
	setAuth(r *http.Request)
}

func basicAuthFromEndpoint(ep *transport.Endpoint) *BasicAuth {
	u := ep.User
	if u == "" {
		return nil
	}

	return &BasicAuth{u, ep.Password}
}

// BasicAuth represent a HTTP basic auth
type BasicAuth struct {
	Username, Password string
}

func (a *BasicAuth) setAuth(r *http.Request) {
	if a == nil {
		return
	}

	r.SetBasicAuth(a.Username, a.Password)
}

// Name is name of the auth
func (a *BasicAuth) Name() string {
	return "http-basic-auth"
}

func (a *BasicAuth) String() string {
	masked := "*******"
	if a.Password == "" {
		masked = "<empty>"
	}

	return fmt.Sprintf("%s - %s:%s", a.Name(), a.Username, masked)
}

// Err is a dedicated error to return errors based on status code
type Err struct {
	Response *http.Response
}

// NewErr returns a new Err based on a http response
func NewErr(r *http.Response) error {
	if r.StatusCode >= http.StatusOK && r.StatusCode < http.StatusMultipleChoices {
		return nil
	}

	switch r.StatusCode {
	case http.StatusUnauthorized:
		return transport.ErrAuthenticationRequired
	case http.StatusForbidden:
		return transport.ErrAuthorizationFailed
	case http.StatusNotFound:
		return transport.ErrRepositoryNotFound
	}

	return plumbing.NewUnexpectedError(&Err{r})
}

// StatusCode returns the status code of the response
func (e *Err) StatusCode() int {
	return e.Response.StatusCode
}

func (e *Err) Error() string {
	return fmt.Sprintf("unexpected requesting %q status code: %d",
		e.Response.Request.URL, e.Response.StatusCode,
	)
}