mech_krb5/support/errors.c

/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* Can't include krb5.h here, or k5-int.h which includes it, because
   krb5.h needs to be generated with error tables, after util/et,
   which builds after this directory.  */
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "k5-err.h"

#include "k5-thread.h"
#include "k5-platform.h"
#include "supp-int.h"

#ifdef USE_KIM
#include "kim_string_private.h"
#endif

/* It would be nice to just use error_message() always.  Pity that
   it's defined in a library that depends on this one, and we're not
   allowed to make circular dependencies.  */
/* We really want a rwlock here, since we should hold it while calling
   the function and copying out its results.  But I haven't
   implemented shims for rwlock yet.  */
static k5_mutex_t krb5int_error_info_support_mutex =
    K5_MUTEX_PARTIAL_INITIALIZER;
static const char *(KRB5_CALLCONV *fptr)(long); /* = &error_message */

int
krb5int_err_init (void)
{
    return k5_mutex_finish_init (&krb5int_error_info_support_mutex);
}
#define initialize()    krb5int_call_thread_support_init()
#define lock()          k5_mutex_lock(&krb5int_error_info_support_mutex)
#define unlock()        k5_mutex_unlock(&krb5int_error_info_support_mutex)

/* Solaris Kerberos */
void
krb5int_vset_error_fl (struct errinfo *, long, const char *, int, const char *,
    va_list);

#undef krb5int_set_error
void
krb5int_set_error (struct errinfo *ep, long code, const char *fmt, ...)
{
    va_list args;
    va_start (args, fmt);
    krb5int_vset_error_fl (ep, code, NULL, 0, fmt, args);
    va_end (args);
}

void
krb5int_set_error_fl (struct errinfo *ep, long code,
                      const char *file, int line, const char *fmt, ...)
{
    va_list args;
    va_start (args, fmt);
    krb5int_vset_error_fl (ep, code, file, line, fmt, args);
    va_end (args);
}

void
krb5int_vset_error (struct errinfo *ep, long code,
                    const char *fmt, va_list args)
{
    krb5int_vset_error_fl(ep, code, NULL, 0, fmt, args);
}

void
krb5int_vset_error_fl (struct errinfo *ep, long code,
                       const char *file, int line,
                       const char *fmt, va_list args)
{
    va_list args2;
    char *str = NULL, *str2, *slash;
#ifdef USE_KIM
    kim_string loc_fmt = NULL;

    /* Try to localize the format string */
    if (kim_os_string_create_localized(&loc_fmt, fmt) == KIM_NO_ERROR)
        fmt = loc_fmt;
#endif

    /* try vasprintf first */
    va_copy(args2, args);
    if (vasprintf(&str, fmt, args2) < 0) {
        str = NULL;
    }
    va_end(args2);

    if (str && line) {
        /* Try to add file and line suffix. */
        slash = strrchr(file, '/');
        if (slash)
            file = slash + 1;
        if (asprintf(&str2, "%s (%s: %d)", str, file, line) > 0) {
            free(str);
            str = str2;
        }
    }

    /* If that failed, try using scratch_buf */
    if (str == NULL) {
        vsnprintf(ep->scratch_buf, sizeof(ep->scratch_buf), fmt, args);
        str = strdup(ep->scratch_buf); /* try allocating again */
    }

    /* free old string before setting new one */
    if (ep->msg && ep->msg != ep->scratch_buf) {
        krb5int_free_error (ep, ep->msg);
        ep->msg = NULL;
    }
    ep->code = code;
    ep->msg = str ? str : ep->scratch_buf;

#ifdef USE_KIM
    kim_string_free(&loc_fmt);
#endif
}

const char *
krb5int_get_error (struct errinfo *ep, long code)
{
    const char *r, *r2;
    if (code == ep->code && ep->msg) {
        r = strdup(ep->msg);
        if (r == NULL) {
            strlcpy(ep->scratch_buf, _("Out of memory"),
                    sizeof(ep->scratch_buf));
            r = ep->scratch_buf;
        }
        return r;
    }
    if (initialize() != 0) {
        strncpy(ep->scratch_buf, _("Kerberos library initialization failure"),
                sizeof(ep->scratch_buf));
        ep->scratch_buf[sizeof(ep->scratch_buf)-1] = 0;
        ep->msg = NULL;
        return ep->scratch_buf;
    }
    if (lock())
        goto no_fptr;
    if (fptr == NULL) {
        unlock();
    no_fptr:
        /* Theoretically, according to ISO C, strerror should be able
           to give us a message back for any int value.  However, on
           UNIX at least, the errno codes strerror will actually be
           useful for are positive, so a negative value here would be
           kind of weird.

           Coverity Prevent thinks we shouldn't be passing negative
           values to strerror, and it's not likely to be useful, so
           let's not do it.

           Besides, normally we shouldn't get here; fptr should take
           us to a callback function in the com_err library.  */
        if (code < 0)
            goto format_number;
#ifdef HAVE_STRERROR_R
        if (strerror_r(code, ep->scratch_buf, sizeof(ep->scratch_buf)) == 0) {
            char *p = strdup(ep->scratch_buf);
            if (p)
                return p;
            return ep->scratch_buf;
        }
#endif
        r = strerror(code);
        if (r) {
            strlcpy(ep->scratch_buf, r, sizeof(ep->scratch_buf));
            return ep->scratch_buf;
        }
    format_number:
        snprintf (ep->scratch_buf, sizeof(ep->scratch_buf),
                  _("error %ld"), code);
        return ep->scratch_buf;
    }
    r = fptr(code);
    if (r == NULL) {
        unlock();
        goto format_number;
    }

    r2 = strdup(r);
    if (r2 == NULL) {
        strlcpy(ep->scratch_buf, r, sizeof(ep->scratch_buf));
        unlock();
        return ep->scratch_buf;
    } else {
        unlock();
        return r2;
    }
}

void
krb5int_free_error (struct errinfo *ep, const char *msg)
{
    if (msg != ep->scratch_buf)
        free ((char *) msg);
}

void
krb5int_clear_error (struct errinfo *ep)
{
    krb5int_free_error (ep, ep->msg);
    ep->msg = NULL;
}

void
krb5int_set_error_info_callout_fn (const char *(KRB5_CALLCONV *f)(long))
{
    initialize();
    if (lock() == 0) {
        fptr = f;
        unlock();
    }
}