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

   1 /*
   2  * Copyright (c) 2010 Andreas Schwab <schwab@linux-m68k.org>
   3  * Copyright (c) 2012-2013 Denys Vlasenko <vda.linux@googlemail.com>
   4  * Copyright (c) 2014 Masatake YAMATO <yamato@redhat.com>
   5  * Copyright (c) 2010-2016 Dmitry V. Levin <ldv@altlinux.org>
   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 #include "msghdr.h"
  33 #include <limits.h>
  34
  35 static int
  36 fetch_struct_mmsghdr_or_printaddr(struct tcb *tcp, const long addr,
  37                                   const unsigned int len, void *const mh)
  38 {
  39         if ((entering(tcp) || !syserror(tcp))
  40             && fetch_struct_mmsghdr(tcp, addr, mh)) {
  41                 return 0;
  42         } else {
  43                 printaddr(addr);
  44                 return -1;
  45         }
  46 }
  47
  48 struct print_struct_mmsghdr_config {
  49         const int *p_user_msg_namelen;
  50         unsigned int msg_len_vlen;
  51         unsigned int count;
  52         bool use_msg_len;
  53 };
  54
  55 static bool
  56 print_struct_mmsghdr(struct tcb *tcp, void *elem_buf,
  57                      size_t elem_size, void *data)
  58 {
  59         const struct mmsghdr *const mmsg = elem_buf;
  60         struct print_struct_mmsghdr_config *const c = data;
  61
  62         if (!c->count) {
  63                 tprints("...");
  64                 return false;
  65         }
  66         --c->count;
  67
  68         tprints("{msg_hdr=");
  69         print_struct_msghdr(tcp, &mmsg->msg_hdr, c->p_user_msg_namelen,
  70                             c->use_msg_len ? mmsg->msg_len : -1UL);
  71         if (c->msg_len_vlen) {
  72                 tprintf(", msg_len=%u", mmsg->msg_len);
  73                 --c->msg_len_vlen;
  74         }
  75         tprints("}");
  76
  77         if (c->p_user_msg_namelen)
  78                 ++c->p_user_msg_namelen;
  79
  80         return true;
  81 }
  82
  83 static void
  84 free_mmsgvec_data(void *ptr)
  85 {
  86         char **pstr = ptr;
  87         free(*pstr);
  88         *pstr = 0;
  89
  90         free(ptr);
  91 }
  92
  93 struct mmsgvec_data {
  94         char *timeout;
  95         unsigned int count;
  96         int namelen[IOV_MAX];
  97 };
  98
  99 static void
 100 save_mmsgvec_namelen(struct tcb *tcp, unsigned long addr,
 101                      unsigned int len, const char *const timeout)
 102 {
 103         if (len > IOV_MAX)
 104                 len = IOV_MAX;
 105
 106         const size_t data_size = offsetof(struct mmsgvec_data, namelen)
 107                                  + sizeof(int) * len;
 108         struct mmsgvec_data *const data = xmalloc(data_size);
 109         data->timeout = xstrdup(timeout);
 110
 111         unsigned int i, fetched;
 112
 113         for (i = 0; i < len; ++i, addr += fetched) {
 114                 struct mmsghdr mh;
 115
 116                 fetched = fetch_struct_mmsghdr(tcp, addr, &mh);
 117                 if (!fetched)
 118                         break;
 119                 data->namelen[i] = mh.msg_hdr.msg_namelen;
 120         }
 121         data->count = i;
 122
 123         set_tcb_priv_data(tcp, data, free_mmsgvec_data);
 124 }
 125
 126 static void
 127 decode_mmsgvec(struct tcb *tcp, const unsigned long addr,
 128                const unsigned int vlen, const unsigned int msg_len_vlen,
 129                const bool use_msg_len)
 130 {
 131         struct mmsghdr mmsg;
 132         struct print_struct_mmsghdr_config c = {
 133                 .msg_len_vlen = msg_len_vlen,
 134                 .count = IOV_MAX,
 135                 .use_msg_len = use_msg_len
 136         };
 137         const struct mmsgvec_data *const data = get_tcb_priv_data(tcp);
 138
 139         if (data) {
 140                 if (data->count < c.count)
 141                         c.count = data->count;
 142                 c.p_user_msg_namelen = data->namelen;
 143         }
 144
 145         print_array(tcp, addr, vlen, &mmsg, sizeof_struct_mmsghdr(),
 146                     fetch_struct_mmsghdr_or_printaddr,
 147                     print_struct_mmsghdr, &c);
 148 }
 149
 150 void
 151 dumpiov_in_mmsghdr(struct tcb *tcp, long addr)
 152 {
 153         unsigned int len = tcp->u_rval;
 154         unsigned int i, fetched;
 155         struct mmsghdr mmsg;
 156
 157         for (i = 0; i < len; ++i, addr += fetched) {
 158                 fetched = fetch_struct_mmsghdr(tcp, addr, &mmsg);
 159                 if (!fetched)
 160                         break;
 161                 tprintf(" = %lu buffers in vector %u\n",
 162                         (unsigned long) mmsg.msg_hdr.msg_iovlen, i);
 163                 dumpiov_upto(tcp, mmsg.msg_hdr.msg_iovlen,
 164                         (long) mmsg.msg_hdr.msg_iov, mmsg.msg_len);
 165         }
 166 }
 167
 168 SYS_FUNC(sendmmsg)
 169 {
 170         if (entering(tcp)) {
 171                 /* sockfd */
 172                 printfd(tcp, tcp->u_arg[0]);
 173                 tprints(", ");
 174                 if (!verbose(tcp)) {
 175                         /* msgvec */
 176                         printaddr(tcp->u_arg[1]);
 177                         /* vlen */
 178                         tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
 179                         /* flags */
 180                         printflags(msg_flags, tcp->u_arg[3], "MSG_???");
 181                         return RVAL_DECODED;
 182                 }
 183         } else {
 184                 const unsigned int msg_len_vlen =
 185                         syserror(tcp) ? 0 : tcp->u_rval;
 186                 /* msgvec */
 187                 temporarily_clear_syserror(tcp);
 188                 decode_mmsgvec(tcp, tcp->u_arg[1], tcp->u_arg[2],
 189                                msg_len_vlen, false);
 190                 restore_cleared_syserror(tcp);
 191                 /* vlen */
 192                 tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
 193                 /* flags */
 194                 printflags(msg_flags, tcp->u_arg[3], "MSG_???");
 195         }
 196         return 0;
 197 }
 198
 199 SYS_FUNC(recvmmsg)
 200 {
 201         if (entering(tcp)) {
 202                 printfd(tcp, tcp->u_arg[0]);
 203                 tprints(", ");
 204                 if (verbose(tcp)) {
 205                         save_mmsgvec_namelen(tcp, tcp->u_arg[1], tcp->u_arg[2],
 206                                              sprint_timespec(tcp, tcp->u_arg[4]));
 207                 } else {
 208                         /* msgvec */
 209                         printaddr(tcp->u_arg[1]);
 210                         /* vlen */
 211                         tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
 212                         /* flags */
 213                         printflags(msg_flags, tcp->u_arg[3], "MSG_???");
 214                         tprints(", ");
 215                         print_timespec(tcp, tcp->u_arg[4]);
 216                 }
 217                 return 0;
 218         } else {
 219                 if (verbose(tcp)) {
 220                         /* msgvec */
 221                         decode_mmsgvec(tcp, tcp->u_arg[1], tcp->u_rval,
 222                                        tcp->u_rval, true);
 223                         /* vlen */
 224                         tprintf(", %u, ", (unsigned int) tcp->u_arg[2]);
 225                         /* flags */
 226                         printflags(msg_flags, tcp->u_arg[3], "MSG_???");
 227                         tprints(", ");
 228                         /* timeout on entrance */
 229                         tprints(*(const char **) get_tcb_priv_data(tcp));
 230                 }
 231                 if (syserror(tcp))
 232                         return 0;
 233                 if (tcp->u_rval == 0) {
 234                         tcp->auxstr = "Timeout";
 235                         return RVAL_STR;
 236                 }
 237                 if (!verbose(tcp) || !tcp->u_arg[4])
 238                         return 0;
 239                 /* timeout on exit */
 240                 static char str[sizeof("left") + TIMESPEC_TEXT_BUFSIZE];
 241                 snprintf(str, sizeof(str), "left %s",
 242                          sprint_timespec(tcp, tcp->u_arg[4]));
 243                 tcp->auxstr = str;
 244                 return RVAL_STR;
 245         }
 246 }