1 /*
2 * socket.c - low-level socket operations
3 */
4
5 #ifdef HAVE_CONFIG_H
6 # include <config.h>
7 #endif
8
9 #include <stdio.h>
10
11 #include "ntp.h"
12 #include "ntp_io.h"
13 #include "ntp_net.h"
14 #include "ntp_debug.h"
15
16 /*
17 * Windows C runtime ioctl() can't deal properly with sockets,
18 * map to ioctlsocket for this source file.
19 */
20 #ifdef SYS_WINNT
21 #define ioctl(fd, opt, val) ioctlsocket(fd, opt, (u_long *)(val))
22 #endif
23
24 /*
25 * on Unix systems the stdio library typically
26 * makes use of file descriptors in the lower
27 * integer range. stdio usually will make use
28 * of the file descriptors in the range of
29 * [0..FOPEN_MAX)
30 * in order to keep this range clean, for socket
31 * file descriptors we attempt to move them above
32 * FOPEN_MAX. This is not as easy as it sounds as
33 * FOPEN_MAX changes from implementation to implementation
34 * and may exceed to current file decriptor limits.
35 * We are using following strategy:
36 * - keep a current socket fd boundary initialized with
37 * max(0, min(GETDTABLESIZE() - FD_CHUNK, FOPEN_MAX))
38 * - attempt to move the descriptor to the boundary or
39 * above.
40 * - if that fails and boundary > 0 set boundary
41 * to min(0, socket_fd_boundary - FD_CHUNK)
42 * -> retry
43 * if failure and boundary == 0 return old fd
44 * - on success close old fd return new fd
45 *
46 * effects:
47 * - fds will be moved above the socket fd boundary
48 * if at all possible.
49 * - the socket boundary will be reduced until
50 * allocation is possible or 0 is reached - at this
51 * point the algrithm will be disabled
52 */
53 SOCKET
move_fd(SOCKET fd)54 move_fd(
55 SOCKET fd
56 )
57 {
58 #if !defined(SYS_WINNT) && defined(F_DUPFD)
59 #ifndef FD_CHUNK
60 #define FD_CHUNK 10
61 #endif
62 #ifndef FOPEN_MAX
63 #define FOPEN_MAX 20
64 #endif
65 /*
66 * number of fds we would like to have for
67 * stdio FILE* available.
68 * we can pick a "low" number as our use of
69 * FILE* is limited to log files and temporarily
70 * to data and config files. Except for log files
71 * we don't keep the other FILE* open beyond the
72 * scope of the function that opened it.
73 */
74 #ifndef FD_PREFERRED_SOCKBOUNDARY
75 #define FD_PREFERRED_SOCKBOUNDARY 48
76 #endif
77
78 static SOCKET socket_boundary = -1;
79 SOCKET newfd;
80
81 REQUIRE((int)fd >= 0);
82
83 /*
84 * check whether boundary has be set up
85 * already
86 */
87 if (socket_boundary == -1) {
88 socket_boundary = max(0, min(GETDTABLESIZE() - FD_CHUNK,
89 min(FOPEN_MAX, FD_PREFERRED_SOCKBOUNDARY)));
90 TRACE(1, ("move_fd: estimated max descriptors: %d, "
91 "initial socket boundary: %d\n",
92 GETDTABLESIZE(), socket_boundary));
93 }
94
95 /*
96 * Leave a space for stdio to work in. potentially moving the
97 * socket_boundary lower until allocation succeeds.
98 */
99 do {
100 if (fd >= 0 && fd < socket_boundary) {
101 /* inside reserved range: attempt to move fd */
102 newfd = fcntl(fd, F_DUPFD, socket_boundary);
103
104 if (newfd != -1) {
105 /* success: drop the old one - return the new one */
106 close(fd);
107 return newfd;
108 }
109 } else {
110 /* outside reserved range: no work - return the original one */
111 return fd;
112 }
113 socket_boundary = max(0, socket_boundary - FD_CHUNK);
114 TRACE(1, ("move_fd: selecting new socket boundary: %d\n",
115 socket_boundary));
116 } while (socket_boundary > 0);
117 #else
118 ENSURE((int)fd >= 0);
119 #endif /* !defined(SYS_WINNT) && defined(F_DUPFD) */
120 return fd;
121 }
122
123
124 /*
125 * make_socket_nonblocking() - set up descriptor to be non blocking
126 */
127 void
make_socket_nonblocking(SOCKET fd)128 make_socket_nonblocking(
129 SOCKET fd
130 )
131 {
132 /*
133 * set non-blocking,
134 */
135
136 #ifdef USE_FIONBIO
137 /* in vxWorks we use FIONBIO, but the others are defined for old
138 * systems, so all hell breaks loose if we leave them defined
139 */
140 #undef O_NONBLOCK
141 #undef FNDELAY
142 #undef O_NDELAY
143 #endif
144
145 #if defined(O_NONBLOCK) /* POSIX */
146 if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
147 msyslog(LOG_ERR,
148 "fcntl(O_NONBLOCK) fails on fd #%d: %m", fd);
149 exit(1);
150 }
151 #elif defined(FNDELAY)
152 if (fcntl(fd, F_SETFL, FNDELAY) < 0) {
153 msyslog(LOG_ERR, "fcntl(FNDELAY) fails on fd #%d: %m",
154 fd);
155 exit(1);
156 }
157 #elif defined(O_NDELAY) /* generally the same as FNDELAY */
158 if (fcntl(fd, F_SETFL, O_NDELAY) < 0) {
159 msyslog(LOG_ERR, "fcntl(O_NDELAY) fails on fd #%d: %m",
160 fd);
161 exit(1);
162 }
163 #elif defined(FIONBIO)
164 {
165 int on = 1;
166
167 if (ioctl(fd, FIONBIO, &on) < 0) {
168 msyslog(LOG_ERR,
169 "ioctl(FIONBIO) fails on fd #%d: %m",
170 fd);
171 exit(1);
172 }
173 }
174 #elif defined(FIOSNBIO)
175 if (ioctl(fd, FIOSNBIO, &on) < 0) {
176 msyslog(LOG_ERR,
177 "ioctl(FIOSNBIO) fails on fd #%d: %m", fd);
178 exit(1);
179 }
180 #else
181 # include "Bletch: Need non-blocking I/O!"
182 #endif
183 }
184
185 #if 0
186
187 /* The following subroutines should probably be moved here */
188
189 static SOCKET
190 open_socket(
191 sockaddr_u * addr,
192 int bcast,
193 int turn_off_reuse,
194 endpt * interf
195 )
196 void
197 sendpkt(
198 sockaddr_u * dest,
199 endpt * ep,
200 int ttl,
201 struct pkt * pkt,
202 int len
203 )
204
205 static inline int
206 read_refclock_packet(SOCKET fd, struct refclockio *rp, l_fp ts)
207
208 static inline int
209 read_network_packet(
210 SOCKET fd,
211 endpt * itf,
212 l_fp ts
213 )
214
215 void
216 kill_asyncio(int startfd)
217
218 #endif /* 0 */
219