constraints.c

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#include "asn_internal.h"
#include "constraints.h"

int
asn_generic_no_constraint(asn_TYPE_descriptor_t *type_descriptor,
    const void *struct_ptr, asn_app_constraint_failed_f *cb, void *key) {

    (void)type_descriptor;  /* Unused argument */
    (void)struct_ptr;   /* Unused argument */
    (void)cb;   /* Unused argument */
    (void)key;  /* Unused argument */

    /* Nothing to check */
    return 0;
}

int
asn_generic_unknown_constraint(asn_TYPE_descriptor_t *type_descriptor,
    const void *struct_ptr, asn_app_constraint_failed_f *cb, void *key) {

    (void)type_descriptor;  /* Unused argument */
    (void)struct_ptr;   /* Unused argument */
    (void)cb;   /* Unused argument */
    (void)key;  /* Unused argument */

    /* Unknown how to check */
    return 0;
}

struct errbufDesc {
    asn_TYPE_descriptor_t *failed_type;
    const void *failed_struct_ptr;
    char *errbuf;
    size_t errlen;
};

static void
_asn_i_ctfailcb(void *key, asn_TYPE_descriptor_t *td, const void *sptr, const char *fmt, ...) {
    struct errbufDesc *arg = key;
    va_list ap;
    ssize_t vlen;
    ssize_t maxlen;

    arg->failed_type = td;
    arg->failed_struct_ptr = sptr;

    maxlen = arg->errlen;
    if(maxlen <= 0)
        return;

    va_start(ap, fmt);
    vlen = vsnprintf(arg->errbuf, maxlen, fmt, ap);
    va_end(ap);
    if(vlen >= maxlen) {
        arg->errbuf[maxlen-1] = '\0';   /* Ensuring libc correctness */
        arg->errlen = maxlen - 1;   /* Not counting termination */
        return;
    } else if(vlen >= 0) {
        arg->errbuf[vlen] = '\0';   /* Ensuring libc correctness */
        arg->errlen = vlen;     /* Not counting termination */
    } else {
        /*
         * The libc on this system is broken.
         */
        vlen = sizeof("<broken vsnprintf>") - 1;
        maxlen--;
        arg->errlen = vlen < maxlen ? vlen : maxlen;
        memcpy(arg->errbuf, "<broken vsnprintf>", arg->errlen);
        arg->errbuf[arg->errlen] = 0;
    }

    return;
}

int
asn_check_constraints(asn_TYPE_descriptor_t *type_descriptor,
        const void *struct_ptr, char *errbuf, size_t *errlen) {
    struct errbufDesc arg;
    int ret;

    arg.failed_type = 0;
    arg.failed_struct_ptr = 0;
    arg.errbuf = errbuf;
    arg.errlen = errlen ? *errlen : 0;

    ret = type_descriptor->check_constraints(type_descriptor,
        struct_ptr, _asn_i_ctfailcb, &arg);
    if(ret == -1 && errlen)
        *errlen = arg.errlen;

    return ret;
}