e2sim/ASN1c/constraints.c

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   2 #                                                                            *
   3 # Copyright 2019 AT&T Intellectual Property                                  *
   4 #                                                                            *
   5 # Licensed under the Apache License, Version 2.0 (the "License");            *
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   7 # You may obtain a copy of the License at                                    *
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   9 #      http://www.apache.org/licenses/LICENSE-2.0                            *
  10 #                                                                            *
  11 # Unless required by applicable law or agreed to in writing, software        *
  12 # distributed under the License is distributed on an "AS IS" BASIS,          *
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   *
  14 # See the License for the specific language governing permissions and        *
  15 # limitations under the License.                                             *
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  17 ******************************************************************************/
  18
  19 #include <asn_internal.h>
  20 #include <constraints.h>
  21
  22 int
  23 asn_generic_no_constraint(const asn_TYPE_descriptor_t *type_descriptor,
  24                           const void *struct_ptr,
  25                           asn_app_constraint_failed_f *cb, void *key) {
  26     (void)type_descriptor;      /* Unused argument */
  27         (void)struct_ptr;       /* Unused argument */
  28         (void)cb;       /* Unused argument */
  29         (void)key;      /* Unused argument */
  30
  31         /* Nothing to check */
  32         return 0;
  33 }
  34
  35 int
  36 asn_generic_unknown_constraint(const asn_TYPE_descriptor_t *type_descriptor,
  37                                const void *struct_ptr,
  38                                asn_app_constraint_failed_f *cb, void *key) {
  39     (void)type_descriptor;      /* Unused argument */
  40         (void)struct_ptr;       /* Unused argument */
  41         (void)cb;       /* Unused argument */
  42         (void)key;      /* Unused argument */
  43
  44         /* Unknown how to check */
  45         return 0;
  46 }
  47
  48 struct errbufDesc {
  49     const asn_TYPE_descriptor_t *failed_type;
  50     const void *failed_struct_ptr;
  51         char *errbuf;
  52         size_t errlen;
  53 };
  54
  55 static void
  56 _asn_i_ctfailcb(void *key, const asn_TYPE_descriptor_t *td, const void *sptr,
  57                 const char *fmt, ...) {
  58     struct errbufDesc *arg = key;
  59         va_list ap;
  60         ssize_t vlen;
  61         ssize_t maxlen;
  62
  63         arg->failed_type = td;
  64         arg->failed_struct_ptr = sptr;
  65
  66         maxlen = arg->errlen;
  67         if(maxlen <= 0)
  68                 return;
  69
  70         va_start(ap, fmt);
  71         vlen = vsnprintf(arg->errbuf, maxlen, fmt, ap);
  72         va_end(ap);
  73         if(vlen >= maxlen) {
  74                 arg->errbuf[maxlen-1] = '\0';   /* Ensuring libc correctness */
  75                 arg->errlen = maxlen - 1;       /* Not counting termination */
  76                 return;
  77         } else if(vlen >= 0) {
  78                 arg->errbuf[vlen] = '\0';       /* Ensuring libc correctness */
  79                 arg->errlen = vlen;             /* Not counting termination */
  80         } else {
  81                 /*
  82                  * The libc on this system is broken.
  83                  */
  84                 vlen = sizeof("<broken vsnprintf>") - 1;
  85                 maxlen--;
  86                 arg->errlen = vlen < maxlen ? vlen : maxlen;
  87                 memcpy(arg->errbuf, "<broken vsnprintf>", arg->errlen);
  88                 arg->errbuf[arg->errlen] = 0;
  89         }
  90
  91         return;
  92 }
  93
  94 int
  95 asn_check_constraints(const asn_TYPE_descriptor_t *type_descriptor,
  96                       const void *struct_ptr, char *errbuf, size_t *errlen) {
  97     struct errbufDesc arg;
  98     int ret;
  99
 100     arg.failed_type = 0;
 101     arg.failed_struct_ptr = 0;
 102     arg.errbuf = errbuf;
 103     arg.errlen = errlen ? *errlen : 0;
 104
 105     ret = type_descriptor->encoding_constraints.general_constraints(
 106         type_descriptor, struct_ptr, _asn_i_ctfailcb, &arg);
 107     if(ret == -1 && errlen) *errlen = arg.errlen;
 108
 109     return ret;
 110 }
 111