1 | /* |
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2 | * $Id$ |
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3 | */ |
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4 | |
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5 | #include <string.h> |
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6 | #include <stdarg.h> |
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7 | /* #include <stdlib.h> */ |
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8 | #include <stdio.h> |
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9 | |
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10 | #include <rtems.h> |
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11 | #include <rtems/libio.h> |
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12 | #include <rtems/error.h> |
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13 | #include <rtems/rtems_bsdnet.h> |
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14 | |
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15 | #include <sys/errno.h> |
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16 | #include <sys/fcntl.h> |
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17 | #include <sys/types.h> |
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18 | #include <sys/param.h> |
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19 | #include <sys/mbuf.h> |
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20 | #include <sys/socket.h> |
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21 | #include <sys/socketvar.h> |
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22 | #include <sys/protosw.h> |
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23 | #include <sys/proc.h> |
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24 | #include <sys/filio.h> |
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25 | |
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26 | #include <net/if.h> |
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27 | #include <net/route.h> |
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28 | |
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29 | /* |
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30 | ********************************************************************* |
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31 | * RTEMS implementation of select() system call * |
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32 | ********************************************************************* |
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33 | */ |
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34 | |
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35 | /* |
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36 | * This implementation is quite restricted: |
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37 | * Works on sockets only -- no support for other devices! |
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38 | * A given socket can be in a read-select or a read/recv* by only |
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39 | * one task at a time. |
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40 | * A given socket can be in a write-select or a write/send* by only |
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41 | * one task at a time. |
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42 | * |
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43 | * NOTE - select() is a very expensive system call. It should be avoided |
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44 | * if at all possible. In many cases, rewriting the application |
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45 | * to use multiple tasks (one per socket) is a better solution. |
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46 | */ |
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47 | |
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48 | static __inline int imin(int a, int b) { return (a < b ? a : b); } |
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49 | struct socket *rtems_bsdnet_fdToSocket(int fd); |
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50 | |
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51 | static int |
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52 | socket_select (struct socket *so, int which, rtems_id tid) |
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53 | { |
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54 | switch (which) { |
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55 | |
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56 | case FREAD: |
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57 | if (soreadable(so)) |
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58 | return (1); |
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59 | so->so_rcv.sb_flags |= SB_WAIT; |
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60 | so->so_rcv.sb_sel.si_pid = tid; |
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61 | break; |
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62 | |
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63 | case FWRITE: |
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64 | if (sowriteable(so)) |
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65 | return (1); |
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66 | so->so_rcv.sb_flags |= SB_WAIT; |
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67 | so->so_snd.sb_sel.si_pid = tid; |
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68 | break; |
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69 | |
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70 | case 0: |
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71 | if (so->so_oobmark || (so->so_state & SS_RCVATMARK)) |
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72 | return (1); |
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73 | so->so_rcv.sb_sel.si_pid = tid; |
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74 | break; |
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75 | } |
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76 | return (0); |
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77 | } |
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78 | |
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79 | static int |
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80 | selscan (rtems_id tid, fd_mask **ibits, fd_mask **obits, int nfd, int *retval) |
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81 | { |
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82 | struct socket *so; |
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83 | int msk, i, fd; |
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84 | fd_mask bits, bit; |
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85 | int n = 0; |
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86 | static int flag[3] = { FREAD, FWRITE, 0 }; |
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87 | |
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88 | for (msk = 0; msk < 3; msk++) { |
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89 | if (ibits[msk] == NULL) |
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90 | continue; |
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91 | for (i = 0; i < nfd; i += NFDBITS) { |
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92 | bits = ibits[msk][i/NFDBITS]; |
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93 | for (fd = i, bit = 1 ; bits && (fd < nfd) ; fd++, bit <<= 1) { |
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94 | if ((bits & bit) == 0) |
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95 | continue; |
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96 | bits &= ~bit; |
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97 | so = rtems_bsdnet_fdToSocket (fd); |
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98 | if (so == NULL) |
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99 | return (EBADF); |
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100 | if (socket_select (so, flag[msk], tid)) { |
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101 | obits[msk][fd/NFDBITS] |= |
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102 | (1 << (fd % NFDBITS)); |
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103 | n++; |
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104 | } |
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105 | } |
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106 | } |
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107 | } |
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108 | *retval = n; |
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109 | return (0); |
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110 | } |
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111 | |
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112 | int |
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113 | select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *tv) |
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114 | { |
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115 | fd_mask *ibits[3], *obits[3]; |
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116 | fd_set ob[3]; |
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117 | int error, timo; |
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118 | int retval; |
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119 | rtems_id tid; |
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120 | rtems_interval then, now; |
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121 | rtems_event_set events; |
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122 | |
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123 | if (nfds < 0) |
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124 | return (EINVAL); |
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125 | if (tv) { |
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126 | timo = tv->tv_sec * hz + tv->tv_usec / tick; |
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127 | if (timo == 0) |
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128 | timo = 1; |
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129 | rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &then); |
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130 | } |
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131 | else { |
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132 | timo = 0; |
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133 | } |
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134 | |
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135 | #define getbits(name,i) if (name) { \ |
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136 | ibits[i] = &name->fds_bits[0]; \ |
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137 | obits[i] = &ob[i].fds_bits[0]; \ |
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138 | FD_ZERO(&ob[i]); \ |
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139 | } \ |
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140 | else ibits[i] = NULL |
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141 | getbits (readfds, 0); |
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142 | getbits (writefds, 1); |
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143 | getbits (exceptfds, 2); |
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144 | #undef getbits |
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145 | |
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146 | rtems_task_ident (RTEMS_SELF, 0, &tid); |
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147 | rtems_event_receive (SBWAIT_EVENT, RTEMS_EVENT_ANY | RTEMS_NO_WAIT, RTEMS_NO_TIMEOUT, &events); |
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148 | for (;;) { |
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149 | rtems_bsdnet_semaphore_obtain (); |
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150 | error = selscan(tid, ibits, obits, nfds, &retval); |
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151 | rtems_bsdnet_semaphore_release (); |
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152 | if (error || retval) |
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153 | break; |
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154 | if (timo) { |
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155 | rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &now); |
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156 | timo -= now - then; |
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157 | if (timo <= 0) |
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158 | break; |
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159 | then = now; |
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160 | } |
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161 | rtems_event_receive (SBWAIT_EVENT, RTEMS_EVENT_ANY | RTEMS_WAIT, timo, &events); |
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162 | } |
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163 | |
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164 | #define putbits(name,i) if (name) *name = ob[i] |
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165 | putbits (readfds, 0); |
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166 | putbits (writefds, 1); |
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167 | putbits (exceptfds, 2); |
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168 | #undef putbits |
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169 | if (error) { |
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170 | errno = error; |
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171 | retval = -1; |
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172 | } |
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173 | return (retval); |
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174 | } |
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