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
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
|
From 228cdb00a045ae3b68a91b35c7548bab6029446e Mon Sep 17 00:00:00 2001
From: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date: Thu, 17 Mar 2022 11:44:34 +0530
Subject: [PATCH] Simplify allocations and fix merge and continue actions [BZ
#28931]
Allocations for address tuples is currently a bit confusing because of
the pointer chasing through PAT, making it hard to observe the sequence
in which allocations have been made. Narrow scope of the pointer
chasing through PAT so that it is only used where necessary.
This also tightens actions behaviour with the hosts database in
getaddrinfo to comply with the manual text. The "continue" action
discards previous results and the "merge" action results in an immedate
lookup failure. Consequently, chaining of allocations across modules is
no longer necessary, thus opening up cleanup opportunities.
A test has been added that checks some combinations to ensure that they
work correctly.
Resolves: BZ #28931
---
sysdeps/posix/getaddrinfo.c | 143 +++++++++++++++++++++++-------------
1 file changed, 91 insertions(+), 52 deletions(-)
diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c
index 9f1cde27..702d8a50 100644
--- a/sysdeps/posix/getaddrinfo.c
+++ b/sysdeps/posix/getaddrinfo.c
@@ -458,11 +458,6 @@ gaih_inet (const char *name, const struct gaih_service *service,
if (name != NULL)
{
- at = alloca_account (sizeof (struct gaih_addrtuple), alloca_used);
- at->family = AF_UNSPEC;
- at->scopeid = 0;
- at->next = NULL;
-
if (req->ai_flags & AI_IDN)
{
char *out;
@@ -473,13 +468,21 @@ gaih_inet (const char *name, const struct gaih_service *service,
malloc_name = true;
}
- if (__inet_aton_exact (name, (struct in_addr *) at->addr) != 0)
+ uint32_t addr[4];
+ if (__inet_aton_exact (name, (struct in_addr *) addr) != 0)
{
+ at = alloca_account (sizeof (struct gaih_addrtuple), alloca_used);
+ at->scopeid = 0;
+ at->next = NULL;
+
if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET)
- at->family = AF_INET;
+ {
+ memcpy (at->addr, addr, sizeof (at->addr));
+ at->family = AF_INET;
+ }
else if (req->ai_family == AF_INET6 && (req->ai_flags & AI_V4MAPPED))
{
- at->addr[3] = at->addr[0];
+ at->addr[3] = addr[0];
at->addr[2] = htonl (0xffff);
at->addr[1] = 0;
at->addr[0] = 0;
@@ -493,49 +496,62 @@ gaih_inet (const char *name, const struct gaih_service *service,
if (req->ai_flags & AI_CANONNAME)
canon = name;
+
+ goto process_list;
}
- else if (at->family == AF_UNSPEC)
+
+ char *scope_delim = strchr (name, SCOPE_DELIMITER);
+ int e;
+
+ if (scope_delim == NULL)
+ e = inet_pton (AF_INET6, name, addr);
+ else
+ e = __inet_pton_length (AF_INET6, name, scope_delim - name, addr);
+
+ if (e > 0)
{
- char *scope_delim = strchr (name, SCOPE_DELIMITER);
- int e;
- if (scope_delim == NULL)
- e = inet_pton (AF_INET6, name, at->addr);
+ at = alloca_account (sizeof (struct gaih_addrtuple),
+ alloca_used);
+ at->scopeid = 0;
+ at->next = NULL;
+
+ if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
+ {
+ memcpy (at->addr, addr, sizeof (at->addr));
+ at->family = AF_INET6;
+ }
+ else if (req->ai_family == AF_INET
+ && IN6_IS_ADDR_V4MAPPED (addr))
+ {
+ at->addr[0] = addr[3];
+ at->addr[1] = addr[1];
+ at->addr[2] = addr[2];
+ at->addr[3] = addr[3];
+ at->family = AF_INET;
+ }
else
- e = __inet_pton_length (AF_INET6, name, scope_delim - name,
- at->addr);
- if (e > 0)
{
- if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
- at->family = AF_INET6;
- else if (req->ai_family == AF_INET
- && IN6_IS_ADDR_V4MAPPED (at->addr))
- {
- at->addr[0] = at->addr[3];
- at->family = AF_INET;
- }
- else
- {
- result = -EAI_ADDRFAMILY;
- goto free_and_return;
- }
-
- if (scope_delim != NULL
- && __inet6_scopeid_pton ((struct in6_addr *) at->addr,
- scope_delim + 1,
- &at->scopeid) != 0)
- {
- result = -EAI_NONAME;
- goto free_and_return;
- }
+ result = -EAI_ADDRFAMILY;
+ goto free_and_return;
+ }
- if (req->ai_flags & AI_CANONNAME)
- canon = name;
+ if (scope_delim != NULL
+ && __inet6_scopeid_pton ((struct in6_addr *) at->addr,
+ scope_delim + 1,
+ &at->scopeid) != 0)
+ {
+ result = -EAI_NONAME;
+ goto free_and_return;
}
+
+ if (req->ai_flags & AI_CANONNAME)
+ canon = name;
+
+ goto process_list;
}
- if (at->family == AF_UNSPEC && (req->ai_flags & AI_NUMERICHOST) == 0)
+ if ((req->ai_flags & AI_NUMERICHOST) == 0)
{
- struct gaih_addrtuple **pat = &at;
int no_data = 0;
int no_inet6_data = 0;
nss_action_list nip;
@@ -543,6 +559,7 @@ gaih_inet (const char *name, const struct gaih_service *service,
enum nss_status status = NSS_STATUS_UNAVAIL;
int no_more;
struct resolv_context *res_ctx = NULL;
+ bool do_merge = false;
/* If we do not have to look for IPv6 addresses or the canonical
name, use the simple, old functions, which do not support
@@ -579,7 +596,7 @@ gaih_inet (const char *name, const struct gaih_service *service,
result = -EAI_MEMORY;
goto free_and_return;
}
- *pat = addrmem;
+ at = addrmem;
}
else
{
@@ -632,6 +649,8 @@ gaih_inet (const char *name, const struct gaih_service *service,
}
struct gaih_addrtuple *addrfree = addrmem;
+ struct gaih_addrtuple **pat = &at;
+
for (int i = 0; i < air->naddrs; ++i)
{
socklen_t size = (air->family[i] == AF_INET
@@ -695,12 +714,6 @@ gaih_inet (const char *name, const struct gaih_service *service,
free (air);
- if (at->family == AF_UNSPEC)
- {
- result = -EAI_NONAME;
- goto free_and_return;
- }
-
goto process_list;
}
else if (err == 0)
@@ -732,6 +745,22 @@ gaih_inet (const char *name, const struct gaih_service *service,
while (!no_more)
{
+ /* Always start afresh; continue should discard previous results
+ and the hosts database does not support merge. */
+ at = NULL;
+ free (canonbuf);
+ free (addrmem);
+ canon = canonbuf = NULL;
+ addrmem = NULL;
+ got_ipv6 = false;
+
+ if (do_merge)
+ {
+ __set_h_errno (NETDB_INTERNAL);
+ __set_errno (EBUSY);
+ break;
+ }
+
no_data = 0;
nss_gethostbyname4_r *fct4 = NULL;
@@ -744,12 +773,14 @@ gaih_inet (const char *name, const struct gaih_service *service,
{
while (1)
{
- status = DL_CALL_FCT (fct4, (name, pat,
+ status = DL_CALL_FCT (fct4, (name, &at,
tmpbuf->data, tmpbuf->length,
&errno, &h_errno,
NULL));
if (status == NSS_STATUS_SUCCESS)
break;
+ /* gethostbyname4_r may write into AT, so reset it. */
+ at = NULL;
if (status != NSS_STATUS_TRYAGAIN
|| errno != ERANGE || h_errno != NETDB_INTERNAL)
{
@@ -774,7 +805,9 @@ gaih_inet (const char *name, const struct gaih_service *service,
no_data = 1;
if ((req->ai_flags & AI_CANONNAME) != 0 && canon == NULL)
- canon = (*pat)->name;
+ canon = at->name;
+
+ struct gaih_addrtuple **pat = &at;
while (*pat != NULL)
{
@@ -826,6 +859,8 @@ gaih_inet (const char *name, const struct gaih_service *service,
if (fct != NULL)
{
+ struct gaih_addrtuple **pat = &at;
+
if (req->ai_family == AF_INET6
|| req->ai_family == AF_UNSPEC)
{
@@ -899,6 +934,10 @@ gaih_inet (const char *name, const struct gaih_service *service,
if (nss_next_action (nip, status) == NSS_ACTION_RETURN)
break;
+ /* The hosts database does not support MERGE. */
+ if (nss_next_action (nip, status) == NSS_ACTION_MERGE)
+ do_merge = true;
+
nip++;
if (nip->module == NULL)
no_more = -1;
@@ -930,7 +969,7 @@ gaih_inet (const char *name, const struct gaih_service *service,
}
process_list:
- if (at->family == AF_UNSPEC)
+ if (at == NULL)
{
result = -EAI_NONAME;
goto free_and_return;
--
2.33.0
|
