source: MondoRescue/branches/3.3/mindi-busybox/libbb/verror_msg.c@ 3621

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
#include "libbb.h"
#if ENABLE_FEATURE_SYSLOG
# include <syslog.h>
#endif

#if ENABLE_FEATURE_SYSLOG
smallint syslog_level = LOG_ERR;
#endif
smallint logmode = LOGMODE_STDIO;
const char *msg_eol = "\n";

void FAST_FUNC bb_verror_msg(const char *s, va_list p, const char* strerr)
{
    char *msg, *msg1;
    char stack_msg[80];
    int applet_len, strerr_len, msgeol_len, used;

    if (!logmode)
        return;

    if (!s) /* nomsg[_and_die] uses NULL fmt */
        s = ""; /* some libc don't like printf(NULL) */

    applet_len = strlen(applet_name) + 2; /* "applet: " */
    strerr_len = strerr ? strlen(strerr) : 0;
    msgeol_len = strlen(msg_eol);

    /* This costs ~90 bytes of code, but avoids costly
     * malloc()[in vasprintf]+realloc()+memmove()+free() in 99% of cases.
     * ~40% speedup.
     */
    if ((int)sizeof(stack_msg) - applet_len > 0) {
        va_list p2;

        /* It is not portable to use va_list twice, need to va_copy it */
        va_copy(p2, p);
        used = vsnprintf(stack_msg + applet_len, (int)sizeof(stack_msg) - applet_len, s, p2);
        va_end(p2);
        msg = stack_msg;
        used += applet_len;
        if (used < (int)sizeof(stack_msg) - 3 - msgeol_len - strerr_len)
            goto add_pfx_and_sfx;
    }

    used = vasprintf(&msg, s, p);
    if (used < 0)
        return;

    /* This is ugly and costs +60 bytes compared to multiple
     * fprintf's, but is guaranteed to do a single write.
     * This is needed for e.g. httpd logging, when multiple
     * children can produce log messages simultaneously. */

    /* can't use xrealloc: it calls error_msg on failure,
     * that may result in a recursion */
    /* +3 is for ": " before strerr and for terminating NUL */
    msg1 = realloc(msg, applet_len + used + strerr_len + msgeol_len + 3);
    if (!msg1) {
        msg[used++] = '\n'; /* overwrites NUL */
        applet_len = 0;
    } else {
        msg = msg1;
        /* TODO: maybe use writev instead of memmoving? Need full_writev? */
        memmove(msg + applet_len, msg, used);
        used += applet_len;
 add_pfx_and_sfx:
        strcpy(msg, applet_name);
        msg[applet_len - 2] = ':';
        msg[applet_len - 1] = ' ';
        if (strerr) {
            if (s[0]) { /* not perror_nomsg? */
                msg[used++] = ':';
                msg[used++] = ' ';
            }
            strcpy(&msg[used], strerr);
            used += strerr_len;
        }
        strcpy(&msg[used], msg_eol);
        used += msgeol_len;
    }

    if (logmode & LOGMODE_STDIO) {
        fflush_all();
        full_write(STDERR_FILENO, msg, used);
    }
#if ENABLE_FEATURE_SYSLOG
    if (logmode & LOGMODE_SYSLOG) {
        syslog(syslog_level, "%s", msg + applet_len);
    }
#endif
    if (msg != stack_msg)
        free(msg);
}

#ifdef VERSION_WITH_WRITEV
/* Code size is approximately the same, but currently it's the only user
 * of writev in entire bbox. __libc_writev in uclibc is ~50 bytes. */
void FAST_FUNC bb_verror_msg(const char *s, va_list p, const char* strerr)
{
    int strerr_len, msgeol_len;
    struct iovec iov[3];

#define used   (iov[2].iov_len)
#define msgv   (iov[2].iov_base)
#define msgc   ((char*)(iov[2].iov_base))
#define msgptr (&(iov[2].iov_base))

    if (!logmode)
        return;

    if (!s) /* nomsg[_and_die] uses NULL fmt */
        s = ""; /* some libc don't like printf(NULL) */

    /* Prevent "derefing type-punned ptr will break aliasing rules" */
    used = vasprintf((char**)(void*)msgptr, s, p);
    if (used < 0)
        return;

    /* This is ugly and costs +60 bytes compared to multiple
     * fprintf's, but is guaranteed to do a single write.
     * This is needed for e.g. httpd logging, when multiple
     * children can produce log messages simultaneously. */

    strerr_len = strerr ? strlen(strerr) : 0;
    msgeol_len = strlen(msg_eol);
    /* +3 is for ": " before strerr and for terminating NUL */
    msgv = xrealloc(msgv, used + strerr_len + msgeol_len + 3);
    if (strerr) {
        msgc[used++] = ':';
        msgc[used++] = ' ';
        strcpy(msgc + used, strerr);
        used += strerr_len;
    }
    strcpy(msgc + used, msg_eol);
    used += msgeol_len;

    if (logmode & LOGMODE_STDIO) {
        iov[0].iov_base = (char*)applet_name;
        iov[0].iov_len = strlen(applet_name);
        iov[1].iov_base = (char*)": ";
        iov[1].iov_len = 2;
        /*iov[2].iov_base = msgc;*/
        /*iov[2].iov_len = used;*/
        fflush_all();
        writev(STDERR_FILENO, iov, 3);
    }
# if ENABLE_FEATURE_SYSLOG
    if (logmode & LOGMODE_SYSLOG) {
        syslog(LOG_ERR, "%s", msgc);
    }
# endif
    free(msgc);
}
#endif


void FAST_FUNC bb_error_msg_and_die(const char *s, ...)
{
    va_list p;

    va_start(p, s);
    bb_verror_msg(s, p, NULL);
    va_end(p);
    xfunc_die();
}

void FAST_FUNC bb_error_msg(const char *s, ...)
{
    va_list p;

    va_start(p, s);
    bb_verror_msg(s, p, NULL);
    va_end(p);
}