libs/smux/constraints.c

   1 #include "asn_internal.h"
   2 #include "constraints.h"
   3
   4 int
   5 asn_generic_no_constraint(asn_TYPE_descriptor_t *type_descriptor,
   6         const void *struct_ptr, asn_app_constraint_failed_f *cb, void *key) {
   7
   8         (void)type_descriptor;  /* Unused argument */
   9         (void)struct_ptr;       /* Unused argument */
  10         (void)cb;       /* Unused argument */
  11         (void)key;      /* Unused argument */
  12
  13         /* Nothing to check */
  14         return 0;
  15 }
  16
  17 int
  18 asn_generic_unknown_constraint(asn_TYPE_descriptor_t *type_descriptor,
  19         const void *struct_ptr, asn_app_constraint_failed_f *cb, void *key) {
  20
  21         (void)type_descriptor;  /* Unused argument */
  22         (void)struct_ptr;       /* Unused argument */
  23         (void)cb;       /* Unused argument */
  24         (void)key;      /* Unused argument */
  25
  26         /* Unknown how to check */
  27         return 0;
  28 }
  29
  30 struct errbufDesc {
  31         asn_TYPE_descriptor_t *failed_type;
  32         const void *failed_struct_ptr;
  33         char *errbuf;
  34         size_t errlen;
  35 };
  36
  37 static void
  38 _asn_i_ctfailcb(void *key, asn_TYPE_descriptor_t *td, const void *sptr, const char *fmt, ...) {
  39         struct errbufDesc *arg = key;
  40         va_list ap;
  41         ssize_t vlen;
  42         ssize_t maxlen;
  43
  44         arg->failed_type = td;
  45         arg->failed_struct_ptr = sptr;
  46
  47         maxlen = arg->errlen;
  48         if(maxlen <= 0)
  49                 return;
  50
  51         va_start(ap, fmt);
  52         vlen = vsnprintf(arg->errbuf, maxlen, fmt, ap);
  53         va_end(ap);
  54         if(vlen >= maxlen) {
  55                 arg->errbuf[maxlen-1] = '\0';   /* Ensuring libc correctness */
  56                 arg->errlen = maxlen - 1;       /* Not counting termination */
  57                 return;
  58         } else if(vlen >= 0) {
  59                 arg->errbuf[vlen] = '\0';       /* Ensuring libc correctness */
  60                 arg->errlen = vlen;             /* Not counting termination */
  61         } else {
  62                 /*
  63                  * The libc on this system is broken.
  64                  */
  65                 vlen = sizeof("<broken vsnprintf>") - 1;
  66                 maxlen--;
  67                 arg->errlen = vlen < maxlen ? vlen : maxlen;
  68                 memcpy(arg->errbuf, "<broken vsnprintf>", arg->errlen);
  69                 arg->errbuf[arg->errlen] = 0;
  70         }
  71
  72         return;
  73 }
  74
  75 int
  76 asn_check_constraints(asn_TYPE_descriptor_t *type_descriptor,
  77                 const void *struct_ptr, char *errbuf, size_t *errlen) {
  78         struct errbufDesc arg;
  79         int ret;
  80
  81         arg.failed_type = 0;
  82         arg.failed_struct_ptr = 0;
  83         arg.errbuf = errbuf;
  84         arg.errlen = errlen ? *errlen : 0;
  85
  86         ret = type_descriptor->check_constraints(type_descriptor,
  87                 struct_ptr, _asn_i_ctfailcb, &arg);
  88         if(ret == -1 && errlen)
  89                 *errlen = arg.errlen;
  90
  91         return ret;
  92 }
  93