Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * ip.c
4 : * IPv6-aware network access.
5 : *
6 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/common/ip.c
12 : *
13 : * This file and the IPV6 implementation were initially provided by
14 : * Nigel Kukard <nkukard@lbsd.net>, Linux Based Systems Design
15 : * http://www.lbsd.net.
16 : *
17 : *-------------------------------------------------------------------------
18 : */
19 :
20 : #ifndef FRONTEND
21 : #include "postgres.h"
22 : #else
23 : #include "postgres_fe.h"
24 : #endif
25 :
26 : #include <unistd.h>
27 : #include <sys/stat.h>
28 : #include <sys/socket.h>
29 : #include <netdb.h>
30 : #include <netinet/in.h>
31 : #include <netinet/tcp.h>
32 : #include <arpa/inet.h>
33 : #include <sys/file.h>
34 :
35 : #include "common/ip.h"
36 :
37 :
38 :
39 : static int getaddrinfo_unix(const char *path,
40 : const struct addrinfo *hintsp,
41 : struct addrinfo **result);
42 :
43 : static int getnameinfo_unix(const struct sockaddr_un *sa, int salen,
44 : char *node, int nodelen,
45 : char *service, int servicelen,
46 : int flags);
47 :
48 :
49 : /*
50 : * pg_getaddrinfo_all - get address info for Unix, IPv4 and IPv6 sockets
51 : *
52 : * The API of this routine differs from the standard getaddrinfo() definition
53 : * in that it requires a valid hintp, a null pointer is not allowed.
54 : */
55 : int
56 38254 : pg_getaddrinfo_all(const char *hostname, const char *servname,
57 : const struct addrinfo *hintp, struct addrinfo **result)
58 : {
59 : int rc;
60 :
61 : /* not all versions of getaddrinfo() zero *result on failure */
62 38254 : *result = NULL;
63 :
64 38254 : if (hintp->ai_family == AF_UNIX)
65 29710 : return getaddrinfo_unix(servname, hintp, result);
66 :
67 : /* NULL has special meaning to getaddrinfo(). */
68 8544 : rc = getaddrinfo((!hostname || hostname[0] == '\0') ? NULL : hostname,
69 : servname, hintp, result);
70 :
71 8544 : return rc;
72 : }
73 :
74 :
75 : /*
76 : * pg_freeaddrinfo_all - free addrinfo structures for IPv4, IPv6, or Unix
77 : *
78 : * Note: the ai_family field of the original hint structure must be passed
79 : * so that we can tell whether the addrinfo struct was built by the system's
80 : * getaddrinfo() routine or our own getaddrinfo_unix() routine. Some versions
81 : * of getaddrinfo() might be willing to return AF_UNIX addresses, so it's
82 : * not safe to look at ai_family in the addrinfo itself.
83 : */
84 : void
85 38254 : pg_freeaddrinfo_all(int hint_ai_family, struct addrinfo *ai)
86 : {
87 38254 : if (hint_ai_family == AF_UNIX)
88 : {
89 : /* struct was built by getaddrinfo_unix (see pg_getaddrinfo_all) */
90 59420 : while (ai != NULL)
91 : {
92 29710 : struct addrinfo *p = ai;
93 :
94 29710 : ai = ai->ai_next;
95 29710 : free(p->ai_addr);
96 29710 : free(p);
97 : }
98 : }
99 : else
100 : {
101 : /* struct was built by getaddrinfo() */
102 8544 : if (ai != NULL)
103 8544 : freeaddrinfo(ai);
104 : }
105 38254 : }
106 :
107 :
108 : /*
109 : * pg_getnameinfo_all - get name info for Unix, IPv4 and IPv6 sockets
110 : *
111 : * The API of this routine differs from the standard getnameinfo() definition
112 : * in two ways: first, the addr parameter is declared as sockaddr_storage
113 : * rather than struct sockaddr, and second, the node and service fields are
114 : * guaranteed to be filled with something even on failure return.
115 : */
116 : int
117 55670 : pg_getnameinfo_all(const struct sockaddr_storage *addr, int salen,
118 : char *node, int nodelen,
119 : char *service, int servicelen,
120 : int flags)
121 : {
122 : int rc;
123 :
124 55670 : if (addr && addr->ss_family == AF_UNIX)
125 54864 : rc = getnameinfo_unix((const struct sockaddr_un *) addr, salen,
126 : node, nodelen,
127 : service, servicelen,
128 : flags);
129 : else
130 806 : rc = getnameinfo((const struct sockaddr *) addr, salen,
131 : node, nodelen,
132 : service, servicelen,
133 : flags);
134 :
135 55670 : if (rc != 0)
136 : {
137 0 : if (node)
138 0 : strlcpy(node, "???", nodelen);
139 0 : if (service)
140 0 : strlcpy(service, "???", servicelen);
141 : }
142 :
143 55670 : return rc;
144 : }
145 :
146 :
147 : /* -------
148 : * getaddrinfo_unix - get unix socket info using IPv6-compatible API
149 : *
150 : * Bugs: only one addrinfo is set even though hintsp is NULL or
151 : * ai_socktype is 0
152 : * AI_CANONNAME is not supported.
153 : * -------
154 : */
155 : static int
156 29710 : getaddrinfo_unix(const char *path, const struct addrinfo *hintsp,
157 : struct addrinfo **result)
158 : {
159 29710 : struct addrinfo hints = {0};
160 : struct addrinfo *aip;
161 : struct sockaddr_un *unp;
162 :
163 29710 : *result = NULL;
164 :
165 29710 : if (strlen(path) >= sizeof(unp->sun_path))
166 0 : return EAI_FAIL;
167 :
168 29710 : if (hintsp == NULL)
169 : {
170 0 : hints.ai_family = AF_UNIX;
171 0 : hints.ai_socktype = SOCK_STREAM;
172 : }
173 : else
174 29710 : memcpy(&hints, hintsp, sizeof(hints));
175 :
176 29710 : if (hints.ai_socktype == 0)
177 0 : hints.ai_socktype = SOCK_STREAM;
178 :
179 29710 : if (hints.ai_family != AF_UNIX)
180 : {
181 : /* shouldn't have been called */
182 0 : return EAI_FAIL;
183 : }
184 :
185 29710 : aip = calloc(1, sizeof(struct addrinfo));
186 29710 : if (aip == NULL)
187 0 : return EAI_MEMORY;
188 :
189 29710 : unp = calloc(1, sizeof(struct sockaddr_un));
190 29710 : if (unp == NULL)
191 : {
192 0 : free(aip);
193 0 : return EAI_MEMORY;
194 : }
195 :
196 29710 : aip->ai_family = AF_UNIX;
197 29710 : aip->ai_socktype = hints.ai_socktype;
198 29710 : aip->ai_protocol = hints.ai_protocol;
199 29710 : aip->ai_next = NULL;
200 29710 : aip->ai_canonname = NULL;
201 29710 : *result = aip;
202 :
203 29710 : unp->sun_family = AF_UNIX;
204 29710 : aip->ai_addr = (struct sockaddr *) unp;
205 29710 : aip->ai_addrlen = sizeof(struct sockaddr_un);
206 :
207 29710 : strcpy(unp->sun_path, path);
208 :
209 : /*
210 : * If the supplied path starts with @, replace that with a zero byte for
211 : * the internal representation. In that mode, the entire sun_path is the
212 : * address, including trailing zero bytes. But we set the address length
213 : * to only include the length of the original string. That way the
214 : * trailing zero bytes won't show up in any network or socket lists of the
215 : * operating system. This is just a convention, also followed by other
216 : * packages.
217 : */
218 29710 : if (path[0] == '@')
219 : {
220 0 : unp->sun_path[0] = '\0';
221 0 : aip->ai_addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(path);
222 : }
223 :
224 29710 : return 0;
225 : }
226 :
227 : /*
228 : * Convert an address to a hostname.
229 : */
230 : static int
231 54864 : getnameinfo_unix(const struct sockaddr_un *sa, int salen,
232 : char *node, int nodelen,
233 : char *service, int servicelen,
234 : int flags)
235 : {
236 : int ret;
237 :
238 : /* Invalid arguments. */
239 54864 : if (sa == NULL || sa->sun_family != AF_UNIX ||
240 27974 : (node == NULL && service == NULL))
241 0 : return EAI_FAIL;
242 :
243 54864 : if (node)
244 : {
245 26890 : ret = snprintf(node, nodelen, "%s", "[local]");
246 26890 : if (ret < 0 || ret >= nodelen)
247 0 : return EAI_MEMORY;
248 : }
249 :
250 54864 : if (service)
251 : {
252 : /*
253 : * Check whether it looks like an abstract socket, but it could also
254 : * just be an empty string.
255 : */
256 54850 : if (sa->sun_path[0] == '\0' && sa->sun_path[1] != '\0')
257 0 : ret = snprintf(service, servicelen, "@%s", sa->sun_path + 1);
258 : else
259 54850 : ret = snprintf(service, servicelen, "%s", sa->sun_path);
260 54850 : if (ret < 0 || ret >= servicelen)
261 0 : return EAI_MEMORY;
262 : }
263 :
264 54864 : return 0;
265 : }
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