1 #include "cache.h"
2 #include "repository.h"
3 #include "refs.h"
4 #include "remote.h"
5 #include "strvec.h"
6 #include "ls-refs.h"
7 #include "pkt-line.h"
8 #include "config.h"
9
10 static int config_read;
11 static int advertise_unborn;
12 static int allow_unborn;
13
ensure_config_read(void)14 static void ensure_config_read(void)
15 {
16 const char *str = NULL;
17
18 if (config_read)
19 return;
20
21 if (repo_config_get_string_tmp(the_repository, "lsrefs.unborn", &str)) {
22 /*
23 * If there is no such config, advertise and allow it by
24 * default.
25 */
26 advertise_unborn = 1;
27 allow_unborn = 1;
28 } else {
29 if (!strcmp(str, "advertise")) {
30 advertise_unborn = 1;
31 allow_unborn = 1;
32 } else if (!strcmp(str, "allow")) {
33 allow_unborn = 1;
34 } else if (!strcmp(str, "ignore")) {
35 /* do nothing */
36 } else {
37 die(_("invalid value '%s' for lsrefs.unborn"), str);
38 }
39 }
40 config_read = 1;
41 }
42
43 /*
44 * If we see this many or more "ref-prefix" lines from the client, we consider
45 * it "too many" and will avoid using the prefix feature entirely.
46 */
47 #define TOO_MANY_PREFIXES 65536
48
49 /*
50 * Check if one of the prefixes is a prefix of the ref.
51 * If no prefixes were provided, all refs match.
52 */
ref_match(const struct strvec * prefixes,const char * refname)53 static int ref_match(const struct strvec *prefixes, const char *refname)
54 {
55 int i;
56
57 if (!prefixes->nr)
58 return 1; /* no restriction */
59
60 for (i = 0; i < prefixes->nr; i++) {
61 const char *prefix = prefixes->v[i];
62
63 if (starts_with(refname, prefix))
64 return 1;
65 }
66
67 return 0;
68 }
69
70 struct ls_refs_data {
71 unsigned peel;
72 unsigned symrefs;
73 struct strvec prefixes;
74 struct strbuf buf;
75 unsigned unborn : 1;
76 };
77
send_ref(const char * refname,const struct object_id * oid,int flag,void * cb_data)78 static int send_ref(const char *refname, const struct object_id *oid,
79 int flag, void *cb_data)
80 {
81 struct ls_refs_data *data = cb_data;
82 const char *refname_nons = strip_namespace(refname);
83
84 strbuf_reset(&data->buf);
85
86 if (ref_is_hidden(refname_nons, refname))
87 return 0;
88
89 if (!ref_match(&data->prefixes, refname_nons))
90 return 0;
91
92 if (oid)
93 strbuf_addf(&data->buf, "%s %s", oid_to_hex(oid), refname_nons);
94 else
95 strbuf_addf(&data->buf, "unborn %s", refname_nons);
96 if (data->symrefs && flag & REF_ISSYMREF) {
97 struct object_id unused;
98 const char *symref_target = resolve_ref_unsafe(refname, 0,
99 &unused,
100 &flag);
101
102 if (!symref_target)
103 die("'%s' is a symref but it is not?", refname);
104
105 strbuf_addf(&data->buf, " symref-target:%s",
106 strip_namespace(symref_target));
107 }
108
109 if (data->peel && oid) {
110 struct object_id peeled;
111 if (!peel_iterated_oid(oid, &peeled))
112 strbuf_addf(&data->buf, " peeled:%s", oid_to_hex(&peeled));
113 }
114
115 strbuf_addch(&data->buf, '\n');
116 packet_fwrite(stdout, data->buf.buf, data->buf.len);
117
118 return 0;
119 }
120
send_possibly_unborn_head(struct ls_refs_data * data)121 static void send_possibly_unborn_head(struct ls_refs_data *data)
122 {
123 struct strbuf namespaced = STRBUF_INIT;
124 struct object_id oid;
125 int flag;
126 int oid_is_null;
127
128 strbuf_addf(&namespaced, "%sHEAD", get_git_namespace());
129 if (!resolve_ref_unsafe(namespaced.buf, 0, &oid, &flag))
130 return; /* bad ref */
131 oid_is_null = is_null_oid(&oid);
132 if (!oid_is_null ||
133 (data->unborn && data->symrefs && (flag & REF_ISSYMREF)))
134 send_ref(namespaced.buf, oid_is_null ? NULL : &oid, flag, data);
135 strbuf_release(&namespaced);
136 }
137
ls_refs_config(const char * var,const char * value,void * data)138 static int ls_refs_config(const char *var, const char *value, void *data)
139 {
140 /*
141 * We only serve fetches over v2 for now, so respect only "uploadpack"
142 * config. This may need to eventually be expanded to "receive", but we
143 * don't yet know how that information will be passed to ls-refs.
144 */
145 return parse_hide_refs_config(var, value, "uploadpack");
146 }
147
ls_refs(struct repository * r,struct packet_reader * request)148 int ls_refs(struct repository *r, struct packet_reader *request)
149 {
150 struct ls_refs_data data;
151
152 memset(&data, 0, sizeof(data));
153 strvec_init(&data.prefixes);
154 strbuf_init(&data.buf, 0);
155
156 ensure_config_read();
157 git_config(ls_refs_config, NULL);
158
159 while (packet_reader_read(request) == PACKET_READ_NORMAL) {
160 const char *arg = request->line;
161 const char *out;
162
163 if (!strcmp("peel", arg))
164 data.peel = 1;
165 else if (!strcmp("symrefs", arg))
166 data.symrefs = 1;
167 else if (skip_prefix(arg, "ref-prefix ", &out)) {
168 if (data.prefixes.nr < TOO_MANY_PREFIXES)
169 strvec_push(&data.prefixes, out);
170 }
171 else if (!strcmp("unborn", arg))
172 data.unborn = allow_unborn;
173 else
174 die(_("unexpected line: '%s'"), arg);
175 }
176
177 if (request->status != PACKET_READ_FLUSH)
178 die(_("expected flush after ls-refs arguments"));
179
180 /*
181 * If we saw too many prefixes, we must avoid using them at all; as
182 * soon as we have any prefix, they are meant to form a comprehensive
183 * list.
184 */
185 if (data.prefixes.nr >= TOO_MANY_PREFIXES)
186 strvec_clear(&data.prefixes);
187
188 send_possibly_unborn_head(&data);
189 if (!data.prefixes.nr)
190 strvec_push(&data.prefixes, "");
191 for_each_fullref_in_prefixes(get_git_namespace(), data.prefixes.v,
192 send_ref, &data);
193 packet_fflush(stdout);
194 strvec_clear(&data.prefixes);
195 strbuf_release(&data.buf);
196 return 0;
197 }
198
ls_refs_advertise(struct repository * r,struct strbuf * value)199 int ls_refs_advertise(struct repository *r, struct strbuf *value)
200 {
201 if (value) {
202 ensure_config_read();
203 if (advertise_unborn)
204 strbuf_addstr(value, "unborn");
205 }
206
207 return 1;
208 }
209