xref: /minix3/minix/lib/libc/sys/recvfrom.c (revision 433d6423c39e34ec4b79c950597bb2d236f886be)
1 #include <sys/cdefs.h>
2 #include "namespace.h"
3 
4 #undef NDEBUG
5 
6 #include <assert.h>
7 #include <errno.h>
8 #include <stdlib.h>
9 #include <stdio.h>
10 #include <string.h>
11 #include <unistd.h>
12 #include <sys/ioctl.h>
13 #include <sys/socket.h>
14 #include <netinet/in.h>
15 
16 #include <net/gen/in.h>
17 #include <net/gen/tcp.h>
18 #include <net/gen/tcp_io.h>
19 #include <net/gen/udp.h>
20 #include <net/gen/udp_hdr.h>
21 #include <net/gen/udp_io.h>
22 
23 #define DEBUG 0
24 
25 static ssize_t _tcp_recvfrom(int sock, void *__restrict buffer, size_t length,
26 	int flags, struct sockaddr *__restrict address,
27 	socklen_t *__restrict address_len, nwio_tcpconf_t *tcpconfp);
28 static ssize_t _udp_recvfrom(int sock, void *__restrict buffer, size_t length,
29 	int flags, struct sockaddr *__restrict address,
30 	socklen_t *__restrict address_len, nwio_udpopt_t *udpoptp);
31 static ssize_t _uds_recvfrom_conn(int sock, void *__restrict buffer,
32 	size_t length, int flags, struct sockaddr *__restrict address,
33 	socklen_t *__restrict address_len, struct sockaddr_un *uds_addr);
34 static ssize_t _uds_recvfrom_dgram(int sock, void *__restrict buffer,
35 	size_t length, int flags, struct sockaddr *__restrict address,
36 	socklen_t *__restrict address_len);
37 
38 ssize_t recvfrom(int sock, void *__restrict buffer, size_t length,
39 	int flags, struct sockaddr *__restrict address,
40 	socklen_t *__restrict address_len)
41 {
42 	int r;
43 	nwio_tcpconf_t tcpconf;
44 	nwio_udpopt_t udpopt;
45 	struct sockaddr_un uds_addr;
46 	int uds_sotype = -1;
47 
48 #if DEBUG
49 	fprintf(stderr, "recvfrom: for fd %d\n", sock);
50 #endif
51 
52 	r= ioctl(sock, NWIOGTCPCONF, &tcpconf);
53 	if (r != -1 || errno != ENOTTY)
54 	{
55 		if (r == -1)
56 			return r;
57 		return _tcp_recvfrom(sock, buffer, length, flags,
58 			address, address_len, &tcpconf);
59 	}
60 
61 	r= ioctl(sock, NWIOGUDPOPT, &udpopt);
62 	if (r != -1 || errno != ENOTTY)
63 	{
64 		if (r == -1)
65 			return r;
66 		return _udp_recvfrom(sock, buffer, length, flags,
67 			address, address_len, &udpopt);
68 	}
69 
70 	r= ioctl(sock, NWIOGUDSSOTYPE, &uds_sotype);
71 	if (r != -1 || errno != ENOTTY)
72 	{
73 
74 		if (r == -1) {
75 			return r;
76 		}
77 
78 		if (uds_sotype == SOCK_DGRAM) {
79 			return _uds_recvfrom_dgram(sock, buffer,
80 				length, flags, address, address_len);
81 		} else {
82 			return _uds_recvfrom_conn(sock, buffer,
83 				length, flags, address, address_len,
84 				&uds_addr);
85 		}
86 	}
87 
88 #if DEBUG
89 	fprintf(stderr, "recvfrom: not implemented for fd %d\n", sock);
90 #endif
91 	errno= ENOSYS;
92 	assert(0);
93 	return -1;
94 }
95 
96 static ssize_t _tcp_recvfrom(int sock, void *__restrict buffer, size_t length,
97 	int flags, struct sockaddr *__restrict address,
98 	socklen_t *__restrict address_len, nwio_tcpconf_t *tcpconfp)
99 {
100 	int r;
101 	size_t len;
102 	struct sockaddr_in sin;
103 
104 	if (flags != 0)
105 	{
106 #if DEBUG
107 		fprintf(stderr, "recvfrom(tcp): flags not implemented\n");
108 #endif
109 		errno= ENOSYS;
110 		return -1;
111 	}
112 
113 	r = read(sock, buffer, length);
114 
115 	if (r >= 0 && address != NULL)
116 	{
117 		sin.sin_family= AF_INET;
118 		sin.sin_addr.s_addr= tcpconfp->nwtc_remaddr;
119 		sin.sin_port= tcpconfp->nwtc_remport;
120 		sin.sin_len= sizeof(sin);
121 		len= *address_len;
122 		if (len > sizeof(sin))
123 			len= sizeof(sin);
124 		memcpy(address, &sin, len);
125 		*address_len= sizeof(sin);
126 	}
127 
128 	return r;
129 }
130 
131 static ssize_t _udp_recvfrom(int sock, void *__restrict buffer, size_t length,
132 	int flags, struct sockaddr *__restrict address,
133 	socklen_t *__restrict address_len, nwio_udpopt_t *udpoptp)
134 {
135 	int r, t_errno;
136 	size_t buflen, len;
137 	void *buf;
138 	udp_io_hdr_t *io_hdrp;
139 	struct sockaddr_in sin;
140 
141 	if (flags)
142 	{
143 #if DEBUG
144 		fprintf(stderr, "recvfrom(udp): flags not implemented\n");
145 #endif
146 		errno= ENOSYS;
147 		return -1;
148 	}
149 
150 	if (udpoptp->nwuo_flags & NWUO_RWDATONLY)
151 	{
152 		if (address != NULL &&
153 			(udpoptp->nwuo_flags & (NWUO_RA_SET | NWUO_RP_SET)) !=
154 			(NWUO_RA_SET | NWUO_RP_SET))
155 		{
156 
157 #if DEBUG
158 			fprintf(stderr,
159 			"recvfrom(udp): RWDATONLY on unconnected socket\n");
160 #endif
161 			errno= ENOTCONN;
162 			return -1;
163 		}
164 
165 		r= read(sock, buffer, length);
166 		if (r == -1)
167 			return r;
168 
169 		if (address != NULL)
170 		{
171 			sin.sin_family= AF_INET;
172 			sin.sin_addr.s_addr= udpoptp->nwuo_remaddr;
173 			sin.sin_port= udpoptp->nwuo_remport;
174 			sin.sin_len= sizeof(sin);
175 			len= *address_len;
176 			if (len > sizeof(sin))
177 				len= sizeof(sin);
178 			memcpy(address, &sin, len);
179 			*address_len= sizeof(sin);
180 		}
181 
182 		return r;
183 	}
184 
185 	buflen= sizeof(*io_hdrp) + length;
186 	if (buflen < length)
187 	{
188 		/* Overflow */
189 		errno= EMSGSIZE;
190 		return -1;
191 	}
192 	buf= malloc(buflen);
193 	if (buf == NULL)
194 		return -1;
195 
196 	r= read(sock, buf, buflen);
197 	if (r == -1)
198 	{
199 		t_errno= errno;
200 #if DEBUG
201 		fprintf(stderr, "recvfrom(udp): read failed: %s\n",
202 			strerror(errno));
203 		fprintf(stderr, "udp opt flags = 0x%x\n", udpoptp->nwuo_flags);
204 #endif
205 		free(buf);
206 		errno= t_errno;
207 		return -1;
208 	}
209 
210 	assert(r >= sizeof(*io_hdrp));
211 	length= r-sizeof(*io_hdrp);
212 
213 	io_hdrp= buf;
214 	memcpy(buffer, &io_hdrp[1], length);
215 
216 	if (address != NULL)
217 	{
218 		sin.sin_family= AF_INET;
219 		sin.sin_addr.s_addr= io_hdrp->uih_src_addr;
220 		sin.sin_port= io_hdrp->uih_src_port;
221 		sin.sin_len= sizeof(sin);
222 		len= *address_len;
223 		if (len > sizeof(sin))
224 			len= sizeof(sin);
225 		memcpy(address, &sin, len);
226 		*address_len= sizeof(sin);
227 	}
228 	free(buf);
229 	return length;
230 }
231 
232 static ssize_t _uds_recvfrom_conn(int sock, void *__restrict buffer,
233 	size_t length, int flags, struct sockaddr *__restrict address,
234 	socklen_t *__restrict address_len, struct sockaddr_un *uds_addr)
235 {
236 	int r;
237 	size_t len;
238 
239 	/* for connection oriented unix domain sockets (SOCK_STREAM /
240 	 * SOCK_SEQPACKET)
241 	 */
242 
243 	if (flags != 0)
244 	{
245 #if DEBUG
246 		fprintf(stderr, "recvfrom(uds): flags not implemented\n");
247 #endif
248 		errno= ENOSYS;
249 		return -1;
250 	}
251 
252 	r = read(sock, buffer, length);
253 
254 	if (r >= 0 && address != NULL)
255 	{
256 
257 		len= *address_len;
258 		if (len > sizeof(struct sockaddr_un))
259 			len= sizeof(struct sockaddr_un);
260 		memcpy(address, uds_addr, len);
261 		*address_len= sizeof(struct sockaddr_un);
262 	}
263 
264 	return r;
265 }
266 
267 static ssize_t _uds_recvfrom_dgram(int sock, void *__restrict buffer,
268 	size_t length, int flags, struct sockaddr *__restrict address,
269 	socklen_t *__restrict address_len)
270 {
271 	int r;
272 	size_t len;
273 
274 	/* for connectionless unix domain sockets (SOCK_DGRAM) */
275 
276 	if (flags != 0)
277 	{
278 #if DEBUG
279 		fprintf(stderr, "recvfrom(uds): flags not implemented\n");
280 #endif
281 		errno= ENOSYS;
282 		return -1;
283 	}
284 
285 	r = read(sock, buffer, length);
286 
287 	if (r >= 0 && address != NULL)
288 	{
289 		len= *address_len;
290 		if (len > sizeof(struct sockaddr_un))
291 			len= sizeof(struct sockaddr_un);
292 		ioctl(sock, NWIOGUDSFADDR, address);
293 		*address_len= sizeof(struct sockaddr_un);
294 	}
295 
296 	return r;
297 }
298 
299