1#include <stdlib.h>
2#include <sys/socket.h>
3#include <netinet/in.h>
4#include <netdb.h>
5#include <string.h>
6#include <pthread.h>
7#include <unistd.h>
8#include <endian.h>
9#include <errno.h>
10#include "lookup.h"
11
12int getaddrinfo(const char *restrict host, const char *restrict serv, const struct addrinfo *restrict hint, struct addrinfo **restrict res)
13{
14 struct service ports[MAXSERVS];
15 struct address addrs[MAXADDRS];
16 char canon[256], *outcanon;
17 int nservs, naddrs, nais, canon_len, i, j, k;
18 int family = AF_UNSPEC, flags = 0, proto = 0, socktype = 0;
19 int no_family = 0;
20 struct aibuf *out;
21
22 if (!host && !serv) return EAI_NONAME;
23
24 if (hint) {
25 family = hint->ai_family;
26 flags = hint->ai_flags;
27 proto = hint->ai_protocol;
28 socktype = hint->ai_socktype;
29
30 const int mask = AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST |
31 AI_V4MAPPED | AI_ALL | AI_ADDRCONFIG | AI_NUMERICSERV;
32 if ((flags & mask) != flags)
33 return EAI_BADFLAGS;
34
35 switch (family) {
36 case AF_INET:
37 case AF_INET6:
38 case AF_UNSPEC:
39 break;
40 default:
41 return EAI_FAMILY;
42 }
43 }
44
45 if (flags & AI_ADDRCONFIG) {
46 /* Define the "an address is configured" condition for address
47 * families via ability to create a socket for the family plus
48 * routability of the loopback address for the family. */
49 static const struct sockaddr_in lo4 = {
50 .sin_family = AF_INET, .sin_port = 65535,
51 .sin_addr.s_addr = __BYTE_ORDER == __BIG_ENDIAN
52 ? 0x7f000001 : 0x0100007f
53 };
54 static const struct sockaddr_in6 lo6 = {
55 .sin6_family = AF_INET6, .sin6_port = 65535,
56 .sin6_addr = IN6ADDR_LOOPBACK_INIT
57 };
58 int tf[2] = { AF_INET, AF_INET6 };
59 const void *ta[2] = { &lo4, &lo6 };
60 socklen_t tl[2] = { sizeof lo4, sizeof lo6 };
61 for (i=0; i<2; i++) {
62 if (family==tf[1-i]) continue;
63 int s = socket(tf[i], SOCK_CLOEXEC|SOCK_DGRAM,
64 IPPROTO_UDP);
65 if (s>=0) {
66 int cs;
67 pthread_setcancelstate(
68 PTHREAD_CANCEL_DISABLE, &cs);
69 int r = connect(s, ta[i], tl[i]);
70 int saved_errno = errno;
71 pthread_setcancelstate(cs, 0);
72 close(s);
73 if (!r) continue;
74 errno = saved_errno;
75 }
76 switch (errno) {
77 case EADDRNOTAVAIL:
78 case EAFNOSUPPORT:
79 case EHOSTUNREACH:
80 case ENETDOWN:
81 case ENETUNREACH:
82 break;
83 default:
84 return EAI_SYSTEM;
85 }
86 if (family == tf[i]) no_family = 1;
87 family = tf[1-i];
88 }
89 }
90
91 nservs = __lookup_serv(ports, serv, proto, socktype, flags);
92 if (nservs < 0) return nservs;
93
94 naddrs = __lookup_name(addrs, canon, host, family, flags);
95 if (naddrs < 0) return naddrs;
96
97 if (no_family) return EAI_NODATA;
98
99 nais = nservs * naddrs;
100 canon_len = strlen(canon);
101 out = calloc(1, nais * sizeof(*out) + canon_len + 1);
102 if (!out) return EAI_MEMORY;
103
104 if (canon_len) {
105 outcanon = (void *)&out[nais];
106 memcpy(outcanon, canon, canon_len+1);
107 } else {
108 outcanon = 0;
109 }
110
111 for (k=i=0; i<naddrs; i++) for (j=0; j<nservs; j++, k++) {
112 out[k].slot = k;
113 out[k].ai = (struct addrinfo){
114 .ai_family = addrs[i].family,
115 .ai_socktype = ports[j].socktype,
116 .ai_protocol = ports[j].proto,
117 .ai_addrlen = addrs[i].family == AF_INET
118 ? sizeof(struct sockaddr_in)
119 : sizeof(struct sockaddr_in6),
120 .ai_addr = (void *)&out[k].sa,
121 .ai_canonname = outcanon };
122 if (k) out[k-1].ai.ai_next = &out[k].ai;
123 switch (addrs[i].family) {
124 case AF_INET:
125 out[k].sa.sin.sin_family = AF_INET;
126 out[k].sa.sin.sin_port = htons(ports[j].port);
127 memcpy(&out[k].sa.sin.sin_addr, &addrs[i].addr, 4);
128 break;
129 case AF_INET6:
130 out[k].sa.sin6.sin6_family = AF_INET6;
131 out[k].sa.sin6.sin6_port = htons(ports[j].port);
132 out[k].sa.sin6.sin6_scope_id = addrs[i].scopeid;
133 memcpy(&out[k].sa.sin6.sin6_addr, &addrs[i].addr, 16);
134 break;
135 }
136 }
137 out[0].ref = nais;
138 *res = &out->ai;
139 return 0;
140}