granicus.if.org Git - strace/blob - desc.c

   1 /*
   2  * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
   3  * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   4  * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
   5  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "defs.h"
  32
  33 SYS_FUNC(close)
  34 {
  35         printfd(tcp, tcp->u_arg[0]);
  36
  37         return RVAL_DECODED;
  38 }
  39
  40 SYS_FUNC(dup)
  41 {
  42         printfd(tcp, tcp->u_arg[0]);
  43
  44         return RVAL_DECODED | RVAL_FD;
  45 }
  46
  47 static int
  48 do_dup2(struct tcb *tcp, int flags_arg)
  49 {
  50         printfd(tcp, tcp->u_arg[0]);
  51         tprints(", ");
  52         printfd(tcp, tcp->u_arg[1]);
  53         if (flags_arg >= 0) {
  54                 tprints(", ");
  55                 printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
  56         }
  57
  58         return RVAL_DECODED | RVAL_FD;
  59 }
  60
  61 SYS_FUNC(dup2)
  62 {
  63         return do_dup2(tcp, -1);
  64 }
  65
  66 SYS_FUNC(dup3)
  67 {
  68         return do_dup2(tcp, 2);
  69 }
  70
  71 static int
  72 decode_select(struct tcb *tcp, kernel_ureg_t *args,
  73               void (*print_tv_ts) (struct tcb *, const long),
  74               const char * (*sprint_tv_ts) (struct tcb *, const long))
  75 {
  76         int i, j;
  77         int nfds, fdsize;
  78         fd_set *fds = NULL;
  79         const char *sep;
  80         long arg;
  81
  82         /* Kernel truncates arg[0] to int, we do the same. */
  83         nfds = (int) args[0];
  84
  85         /* Kernel rejects negative nfds, so we don't parse it either. */
  86         if (nfds < 0)
  87                 nfds = 0;
  88
  89         /* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
  90         if (nfds > 1024*1024)
  91                 nfds = 1024*1024;
  92
  93         /*
  94          * We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
  95          * Instead of args[0], use nfds for fd count, fdsize for array lengths.
  96          */
  97         fdsize = (((nfds + 7) / 8) + current_wordsize-1) & -current_wordsize;
  98
  99         if (entering(tcp)) {
 100                 tprintf("%d", (int) args[0]);
 101
 102                 if (verbose(tcp) && fdsize > 0)
 103                         fds = malloc(fdsize);
 104                 for (i = 0; i < 3; i++) {
 105                         arg = args[i+1];
 106                         tprints(", ");
 107                         if (!fds) {
 108                                 printaddr(arg);
 109                                 continue;
 110                         }
 111                         if (umoven_or_printaddr(tcp, arg, fdsize, fds))
 112                                 continue;
 113                         tprints("[");
 114                         for (j = 0, sep = "";; j++) {
 115                                 j = next_set_bit(fds, j, nfds);
 116                                 if (j < 0)
 117                                         break;
 118                                 tprints(sep);
 119                                 printfd(tcp, j);
 120                                 sep = " ";
 121                         }
 122                         tprints("]");
 123                 }
 124                 free(fds);
 125                 tprints(", ");
 126                 print_tv_ts(tcp, args[4]);
 127         } else {
 128                 static char outstr[1024];
 129                 char *outptr;
 130 #define end_outstr (outstr + sizeof(outstr))
 131                 int ready_fds;
 132
 133                 if (syserror(tcp))
 134                         return 0;
 135
 136                 ready_fds = tcp->u_rval;
 137                 if (ready_fds == 0) {
 138                         tcp->auxstr = "Timeout";
 139                         return RVAL_STR;
 140                 }
 141
 142                 fds = malloc(fdsize);
 143
 144                 outptr = outstr;
 145                 sep = "";
 146                 for (i = 0; i < 3 && ready_fds > 0; i++) {
 147                         int first = 1;
 148
 149                         arg = args[i+1];
 150                         if (!arg || !fds || umoven(tcp, arg, fdsize, fds) < 0)
 151                                 continue;
 152                         for (j = 0;; j++) {
 153                                 j = next_set_bit(fds, j, nfds);
 154                                 if (j < 0)
 155                                         break;
 156                                 /* +2 chars needed at the end: ']',NUL */
 157                                 if (outptr < end_outstr - (sizeof(", except [") + sizeof(int)*3 + 2)) {
 158                                         if (first) {
 159                                                 outptr += sprintf(outptr, "%s%s [%u",
 160                                                         sep,
 161                                                         i == 0 ? "in" : i == 1 ? "out" : "except",
 162                                                         j
 163                                                 );
 164                                                 first = 0;
 165                                                 sep = ", ";
 166                                         }
 167                                         else {
 168                                                 outptr += sprintf(outptr, " %u", j);
 169                                         }
 170                                 }
 171                                 if (--ready_fds == 0)
 172                                         break;
 173                         }
 174                         if (outptr != outstr)
 175                                 *outptr++ = ']';
 176                 }
 177                 free(fds);
 178                 /* This contains no useful information on SunOS.  */
 179                 if (args[4]) {
 180                         const char *str = sprint_tv_ts(tcp, args[4]);
 181                         if (outptr + sizeof("left ") + strlen(sep) + strlen(str) < end_outstr) {
 182                                 outptr += sprintf(outptr, "%sleft %s", sep, str);
 183                         }
 184                 }
 185                 *outptr = '\0';
 186                 tcp->auxstr = outstr;
 187                 return RVAL_STR;
 188 #undef end_outstr
 189         }
 190         return 0;
 191 }
 192
 193 SYS_FUNC(oldselect)
 194 {
 195         kernel_ureg_t select_args[5];
 196         unsigned int oldselect_args[5];
 197
 198         if (sizeof(*select_args) == sizeof(*oldselect_args)) {
 199                 if (umove_or_printaddr(tcp, tcp->u_arg[0], &select_args)) {
 200                         return 0;
 201                 }
 202         } else {
 203                 unsigned int i;
 204
 205                 if (umove_or_printaddr(tcp, tcp->u_arg[0], &oldselect_args)) {
 206                         return 0;
 207                 }
 208
 209                 for (i = 0; i < 5; ++i) {
 210                         select_args[i] = oldselect_args[i];
 211                 }
 212         }
 213
 214         return decode_select(tcp, select_args, print_timeval, sprint_timeval);
 215 }
 216
 217 #ifdef ALPHA
 218 SYS_FUNC(osf_select)
 219 {
 220         return decode_select(tcp, tcp->u_arg, print_timeval32, sprint_timeval32);
 221 }
 222 #endif
 223
 224 SYS_FUNC(select)
 225 {
 226         return decode_select(tcp, tcp->u_arg, print_timeval, sprint_timeval);
 227 }
 228
 229 static int
 230 umove_kulong_array_or_printaddr(struct tcb *tcp, const long addr,
 231                                 kernel_ulong_t *ptr, size_t n)
 232 {
 233 #ifndef current_klongsize
 234         if (current_klongsize < sizeof(*ptr)) {
 235                 uint32_t ptr32[n];
 236                 int r = umove_or_printaddr(tcp, addr, &ptr32);
 237                 if (!r) {
 238                         size_t i;
 239
 240                         for (i = 0; i < n; ++i)
 241                                 ptr[i] = (kernel_ulong_t) ptr32[i];
 242                 }
 243                 return r;
 244         }
 245 #endif /* !current_klongsize */
 246         return umoven_or_printaddr(tcp, addr, n * sizeof(*ptr), ptr);
 247 }
 248
 249 SYS_FUNC(pselect6)
 250 {
 251         int rc = decode_select(tcp, tcp->u_arg, print_timespec, sprint_timespec);
 252         if (entering(tcp)) {
 253                 kernel_ulong_t data[2];
 254
 255                 tprints(", ");
 256                 if (!umove_kulong_array_or_printaddr(tcp, tcp->u_arg[5],
 257                                                      data, ARRAY_SIZE(data))) {
 258                         tprints("{");
 259                         /* NB: kernel requires data[1] == NSIG / 8 */
 260                         print_sigset_addr_len(tcp, (unsigned long) data[0],
 261                                               (unsigned long) data[1]);
 262                         tprintf(", %" PRI_klu "}", data[1]);
 263                 }
 264         }
 265
 266         return rc;
 267 }