summaryrefslogtreecommitdiffstats
path: root/sys/kern/subr_prf.c
diff options
context:
space:
mode:
Diffstat (limited to 'sys/kern/subr_prf.c')
-rw-r--r--sys/kern/subr_prf.c905
1 files changed, 905 insertions, 0 deletions
diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c
new file mode 100644
index 0000000..7f9b790
--- /dev/null
+++ b/sys/kern/subr_prf.c
@@ -0,0 +1,905 @@
+/*-
+ * Copyright (c) 1986, 1988, 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)subr_prf.c 8.3 (Berkeley) 1/21/94
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/sx.h>
+#include <sys/kernel.h>
+#include <sys/msgbuf.h>
+#include <sys/malloc.h>
+#include <sys/proc.h>
+#include <sys/stdint.h>
+#include <sys/sysctl.h>
+#include <sys/tty.h>
+#include <sys/syslog.h>
+#include <sys/cons.h>
+#include <sys/uio.h>
+
+/*
+ * Note that stdarg.h and the ANSI style va_start macro is used for both
+ * ANSI and traditional C compilers.
+ */
+#include <machine/stdarg.h>
+
+#define TOCONS 0x01
+#define TOTTY 0x02
+#define TOLOG 0x04
+
+/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
+#define MAXNBUF (sizeof(intmax_t) * NBBY + 1)
+
+struct putchar_arg {
+ int flags;
+ int pri;
+ struct tty *tty;
+};
+
+struct snprintf_arg {
+ char *str;
+ size_t remain;
+};
+
+extern int log_open;
+
+struct tty *constty; /* pointer to console "window" tty */
+
+static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */
+static void msglogchar(int c, int pri);
+static void msgaddchar(int c, void *dummy);
+static void putchar(int ch, void *arg);
+static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len);
+static void snprintf_func(int ch, void *arg);
+
+static int consintr = 1; /* Ok to handle console interrupts? */
+static int msgbufmapped; /* Set when safe to use msgbuf */
+int msgbuftrigger;
+
+static int log_console_output = 1;
+SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
+ &log_console_output, 0, "");
+
+/*
+ * Warn that a system table is full.
+ */
+void
+tablefull(const char *tab)
+{
+
+ log(LOG_ERR, "%s: table is full\n", tab);
+}
+
+/*
+ * Uprintf prints to the controlling terminal for the current process.
+ * It may block if the tty queue is overfull. No message is printed if
+ * the queue does not clear in a reasonable time.
+ */
+int
+uprintf(const char *fmt, ...)
+{
+ struct thread *td = curthread;
+ struct proc *p = td->td_proc;
+ va_list ap;
+ struct putchar_arg pca;
+ int retval;
+
+ if (td == NULL || td == PCPU_GET(idlethread))
+ return (0);
+
+ p = td->td_proc;
+ PROC_LOCK(p);
+ if ((p->p_flag & P_CONTROLT) == 0) {
+ PROC_UNLOCK(p);
+ return (0);
+ }
+ SESS_LOCK(p->p_session);
+ pca.tty = p->p_session->s_ttyp;
+ SESS_UNLOCK(p->p_session);
+ PROC_UNLOCK(p);
+ if (pca.tty == NULL)
+ return (0);
+ pca.flags = TOTTY;
+ va_start(ap, fmt);
+ retval = kvprintf(fmt, putchar, &pca, 10, ap);
+ va_end(ap);
+
+ return (retval);
+}
+
+/*
+ * tprintf prints on the controlling terminal associated
+ * with the given session, possibly to the log as well.
+ */
+void
+tprintf(struct proc *p, int pri, const char *fmt, ...)
+{
+ struct tty *tp = NULL;
+ int flags = 0, shld = 0;
+ va_list ap;
+ struct putchar_arg pca;
+ int retval;
+
+ if (pri != -1)
+ flags |= TOLOG;
+ if (p != NULL) {
+ PROC_LOCK(p);
+ if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
+ SESS_LOCK(p->p_session);
+ SESSHOLD(p->p_session);
+ tp = p->p_session->s_ttyp;
+ SESS_UNLOCK(p->p_session);
+ PROC_UNLOCK(p);
+ shld++;
+ if (ttycheckoutq(tp, 0))
+ flags |= TOTTY;
+ else
+ tp = NULL;
+ } else
+ PROC_UNLOCK(p);
+ }
+ pca.pri = pri;
+ pca.tty = tp;
+ pca.flags = flags;
+ va_start(ap, fmt);
+ retval = kvprintf(fmt, putchar, &pca, 10, ap);
+ va_end(ap);
+ if (shld) {
+ PROC_LOCK(p);
+ SESS_LOCK(p->p_session);
+ SESSRELE(p->p_session);
+ SESS_UNLOCK(p->p_session);
+ PROC_UNLOCK(p);
+ }
+ msgbuftrigger = 1;
+}
+
+/*
+ * Ttyprintf displays a message on a tty; it should be used only by
+ * the tty driver, or anything that knows the underlying tty will not
+ * be revoke(2)'d away. Other callers should use tprintf.
+ */
+int
+ttyprintf(struct tty *tp, const char *fmt, ...)
+{
+ va_list ap;
+ struct putchar_arg pca;
+ int retval;
+
+ va_start(ap, fmt);
+ pca.tty = tp;
+ pca.flags = TOTTY;
+ retval = kvprintf(fmt, putchar, &pca, 10, ap);
+ va_end(ap);
+ return (retval);
+}
+
+/*
+ * Log writes to the log buffer, and guarantees not to sleep (so can be
+ * called by interrupt routines). If there is no process reading the
+ * log yet, it writes to the console also.
+ */
+void
+log(int level, const char *fmt, ...)
+{
+ va_list ap;
+ int retval;
+ struct putchar_arg pca;
+
+ pca.tty = NULL;
+ pca.pri = level;
+ pca.flags = log_open ? TOLOG : TOCONS;
+
+ va_start(ap, fmt);
+ retval = kvprintf(fmt, putchar, &pca, 10, ap);
+ va_end(ap);
+
+ msgbuftrigger = 1;
+}
+
+#define CONSCHUNK 128
+
+void
+log_console(struct uio *uio)
+{
+ int c, i, error, iovlen, nl;
+ struct uio muio;
+ struct iovec *miov = NULL;
+ char *consbuffer;
+ int pri;
+
+ if (!log_console_output)
+ return;
+
+ pri = LOG_INFO | LOG_CONSOLE;
+ muio = *uio;
+ iovlen = uio->uio_iovcnt * sizeof (struct iovec);
+ MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
+ MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
+ bcopy(muio.uio_iov, miov, iovlen);
+ muio.uio_iov = miov;
+ uio = &muio;
+
+ nl = 0;
+ while (uio->uio_resid > 0) {
+ c = imin(uio->uio_resid, CONSCHUNK);
+ error = uiomove(consbuffer, c, uio);
+ if (error != 0)
+ return;
+ for (i = 0; i < c; i++) {
+ msglogchar(consbuffer[i], pri);
+ if (consbuffer[i] == '\n')
+ nl = 1;
+ else
+ nl = 0;
+ }
+ }
+ if (!nl)
+ msglogchar('\n', pri);
+ msgbuftrigger = 1;
+ FREE(miov, M_TEMP);
+ FREE(consbuffer, M_TEMP);
+ return;
+}
+
+int
+printf(const char *fmt, ...)
+{
+ va_list ap;
+ int savintr;
+ struct putchar_arg pca;
+ int retval;
+
+ savintr = consintr; /* disable interrupts */
+ consintr = 0;
+ va_start(ap, fmt);
+ pca.tty = NULL;
+ pca.flags = TOCONS | TOLOG;
+ pca.pri = -1;
+ retval = kvprintf(fmt, putchar, &pca, 10, ap);
+ va_end(ap);
+ if (!panicstr)
+ msgbuftrigger = 1;
+ consintr = savintr; /* reenable interrupts */
+ return (retval);
+}
+
+int
+vprintf(const char *fmt, va_list ap)
+{
+ int savintr;
+ struct putchar_arg pca;
+ int retval;
+
+ savintr = consintr; /* disable interrupts */
+ consintr = 0;
+ pca.tty = NULL;
+ pca.flags = TOCONS | TOLOG;
+ pca.pri = -1;
+ retval = kvprintf(fmt, putchar, &pca, 10, ap);
+ if (!panicstr)
+ msgbuftrigger = 1;
+ consintr = savintr; /* reenable interrupts */
+ return (retval);
+}
+
+/*
+ * Print a character on console or users terminal. If destination is
+ * the console then the last bunch of characters are saved in msgbuf for
+ * inspection later.
+ */
+static void
+putchar(int c, void *arg)
+{
+ struct putchar_arg *ap = (struct putchar_arg*) arg;
+ int flags = ap->flags;
+ struct tty *tp = ap->tty;
+ if (panicstr)
+ constty = NULL;
+ if ((flags & TOCONS) && tp == NULL && constty) {
+ tp = constty;
+ flags |= TOTTY;
+ }
+ if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
+ (flags & TOCONS) && tp == constty)
+ constty = NULL;
+ if ((flags & TOLOG))
+ msglogchar(c, ap->pri);
+ if ((flags & TOCONS) && constty == NULL && c != '\0')
+ (*v_putc)(c);
+}
+
+/*
+ * Scaled down version of sprintf(3).
+ */
+int
+sprintf(char *buf, const char *cfmt, ...)
+{
+ int retval;
+ va_list ap;
+
+ va_start(ap, cfmt);
+ retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
+ buf[retval] = '\0';
+ va_end(ap);
+ return (retval);
+}
+
+/*
+ * Scaled down version of vsprintf(3).
+ */
+int
+vsprintf(char *buf, const char *cfmt, va_list ap)
+{
+ int retval;
+
+ retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
+ buf[retval] = '\0';
+ return (retval);
+}
+
+/*
+ * Scaled down version of snprintf(3).
+ */
+int
+snprintf(char *str, size_t size, const char *format, ...)
+{
+ int retval;
+ va_list ap;
+
+ va_start(ap, format);
+ retval = vsnprintf(str, size, format, ap);
+ va_end(ap);
+ return(retval);
+}
+
+/*
+ * Scaled down version of vsnprintf(3).
+ */
+int
+vsnprintf(char *str, size_t size, const char *format, va_list ap)
+{
+ struct snprintf_arg info;
+ int retval;
+
+ info.str = str;
+ info.remain = size;
+ retval = kvprintf(format, snprintf_func, &info, 10, ap);
+ if (info.remain >= 1)
+ *info.str++ = '\0';
+ return (retval);
+}
+
+static void
+snprintf_func(int ch, void *arg)
+{
+ struct snprintf_arg *const info = arg;
+
+ if (info->remain >= 2) {
+ *info->str++ = ch;
+ info->remain--;
+ }
+}
+
+/*
+ * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
+ * order; return an optional length and a pointer to the last character
+ * written in the buffer (i.e., the first character of the string).
+ * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
+ */
+static char *
+ksprintn(char *nbuf, uintmax_t num, int base, int *lenp)
+{
+ char *p;
+
+ p = nbuf;
+ *p = '\0';
+ do {
+ *++p = hex2ascii(num % base);
+ } while (num /= base);
+ if (lenp)
+ *lenp = p - nbuf;
+ return (p);
+}
+
+/*
+ * Scaled down version of printf(3).
+ *
+ * Two additional formats:
+ *
+ * The format %b is supported to decode error registers.
+ * Its usage is:
+ *
+ * printf("reg=%b\n", regval, "<base><arg>*");
+ *
+ * where <base> is the output base expressed as a control character, e.g.
+ * \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
+ * the first of which gives the bit number to be inspected (origin 1), and
+ * the next characters (up to a control character, i.e. a character <= 32),
+ * give the name of the register. Thus:
+ *
+ * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
+ *
+ * would produce output:
+ *
+ * reg=3<BITTWO,BITONE>
+ *
+ * XXX: %D -- Hexdump, takes pointer and separator string:
+ * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX
+ * ("%*D", len, ptr, " " -> XX XX XX XX ...
+ */
+int
+kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
+{
+#define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
+ char nbuf[MAXNBUF];
+ char *d;
+ const char *p, *percent, *q;
+ u_char *up;
+ int ch, n;
+ uintmax_t num;
+ int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
+ int jflag;
+ int dwidth;
+ char padc;
+ int retval = 0;
+
+ num = 0;
+ if (!func)
+ d = (char *) arg;
+ else
+ d = NULL;
+
+ if (fmt == NULL)
+ fmt = "(fmt null)\n";
+
+ if (radix < 2 || radix > 36)
+ radix = 10;
+
+ for (;;) {
+ padc = ' ';
+ width = 0;
+ while ((ch = (u_char)*fmt++) != '%') {
+ if (ch == '\0')
+ return (retval);
+ PCHAR(ch);
+ }
+ percent = fmt - 1;
+ qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
+ sign = 0; dot = 0; dwidth = 0;
+ jflag = 0;
+reswitch: switch (ch = (u_char)*fmt++) {
+ case '.':
+ dot = 1;
+ goto reswitch;
+ case '#':
+ sharpflag = 1;
+ goto reswitch;
+ case '+':
+ sign = 1;
+ goto reswitch;
+ case '-':
+ ladjust = 1;
+ goto reswitch;
+ case '%':
+ PCHAR(ch);
+ break;
+ case '*':
+ if (!dot) {
+ width = va_arg(ap, int);
+ if (width < 0) {
+ ladjust = !ladjust;
+ width = -width;
+ }
+ } else {
+ dwidth = va_arg(ap, int);
+ }
+ goto reswitch;
+ case '0':
+ if (!dot) {
+ padc = '0';
+ goto reswitch;
+ }
+ case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ for (n = 0;; ++fmt) {
+ n = n * 10 + ch - '0';
+ ch = *fmt;
+ if (ch < '0' || ch > '9')
+ break;
+ }
+ if (dot)
+ dwidth = n;
+ else
+ width = n;
+ goto reswitch;
+ case 'b':
+ num = va_arg(ap, int);
+ p = va_arg(ap, char *);
+ for (q = ksprintn(nbuf, num, *p++, NULL); *q;)
+ PCHAR(*q--);
+
+ if (num == 0)
+ break;
+
+ for (tmp = 0; *p;) {
+ n = *p++;
+ if (num & (1 << (n - 1))) {
+ PCHAR(tmp ? ',' : '<');
+ for (; (n = *p) > ' '; ++p)
+ PCHAR(n);
+ tmp = 1;
+ } else
+ for (; *p > ' '; ++p)
+ continue;
+ }
+ if (tmp)
+ PCHAR('>');
+ break;
+ case 'c':
+ PCHAR(va_arg(ap, int));
+ break;
+ case 'D':
+ up = va_arg(ap, u_char *);
+ p = va_arg(ap, char *);
+ if (!width)
+ width = 16;
+ while(width--) {
+ PCHAR(hex2ascii(*up >> 4));
+ PCHAR(hex2ascii(*up & 0x0f));
+ up++;
+ if (width)
+ for (q=p;*q;q++)
+ PCHAR(*q);
+ }
+ break;
+ case 'd':
+ base = 10;
+ sign = 1;
+ goto handle_sign;
+ case 'j':
+ jflag = 1;
+ goto reswitch;
+ case 'l':
+ if (lflag) {
+ lflag = 0;
+ qflag = 1;
+ } else
+ lflag = 1;
+ goto reswitch;
+ case 'n':
+ if (jflag)
+ *(va_arg(ap, intmax_t *)) = retval;
+ else if (qflag)
+ *(va_arg(ap, quad_t *)) = retval;
+ else if (lflag)
+ *(va_arg(ap, long *)) = retval;
+ else
+ *(va_arg(ap, int *)) = retval;
+ break;
+ case 'o':
+ base = 8;
+ goto handle_nosign;
+ case 'p':
+ base = 16;
+ sharpflag = (width == 0);
+ sign = 0;
+ num = (uintptr_t)va_arg(ap, void *);
+ goto number;
+ case 'q':
+ qflag = 1;
+ goto reswitch;
+ case 'r':
+ base = radix;
+ if (sign)
+ goto handle_sign;
+ goto handle_nosign;
+ case 's':
+ p = va_arg(ap, char *);
+ if (p == NULL)
+ p = "(null)";
+ if (!dot)
+ n = strlen (p);
+ else
+ for (n = 0; n < dwidth && p[n]; n++)
+ continue;
+
+ width -= n;
+
+ if (!ladjust && width > 0)
+ while (width--)
+ PCHAR(padc);
+ while (n--)
+ PCHAR(*p++);
+ if (ladjust && width > 0)
+ while (width--)
+ PCHAR(padc);
+ break;
+ case 'u':
+ base = 10;
+ goto handle_nosign;
+ case 'x':
+ case 'X':
+ base = 16;
+ goto handle_nosign;
+ case 'z':
+ base = 16;
+ if (sign)
+ goto handle_sign;
+handle_nosign:
+ sign = 0;
+ if (jflag)
+ num = va_arg(ap, uintmax_t);
+ else if (qflag)
+ num = va_arg(ap, u_quad_t);
+ else if (lflag)
+ num = va_arg(ap, u_long);
+ else
+ num = va_arg(ap, u_int);
+ goto number;
+handle_sign:
+ if (jflag)
+ num = va_arg(ap, intmax_t);
+ else if (qflag)
+ num = va_arg(ap, quad_t);
+ else if (lflag)
+ num = va_arg(ap, long);
+ else
+ num = va_arg(ap, int);
+number:
+ if (sign && (intmax_t)num < 0) {
+ neg = 1;
+ num = -(intmax_t)num;
+ }
+ p = ksprintn(nbuf, num, base, &tmp);
+ if (sharpflag && num != 0) {
+ if (base == 8)
+ tmp++;
+ else if (base == 16)
+ tmp += 2;
+ }
+ if (neg)
+ tmp++;
+
+ if (!ladjust && width && (width -= tmp) > 0)
+ while (width--)
+ PCHAR(padc);
+ if (neg)
+ PCHAR('-');
+ if (sharpflag && num != 0) {
+ if (base == 8) {
+ PCHAR('0');
+ } else if (base == 16) {
+ PCHAR('0');
+ PCHAR('x');
+ }
+ }
+
+ while (*p)
+ PCHAR(*p--);
+
+ if (ladjust && width && (width -= tmp) > 0)
+ while (width--)
+ PCHAR(padc);
+
+ break;
+ default:
+ while (percent < fmt)
+ PCHAR(*percent++);
+ break;
+ }
+ }
+#undef PCHAR
+}
+
+/*
+ * Put character in log buffer with a particular priority.
+ */
+static void
+msglogchar(int c, int pri)
+{
+ static int lastpri = -1;
+ static int dangling;
+ char nbuf[MAXNBUF];
+ char *p;
+
+ if (!msgbufmapped)
+ return;
+ if (c == '\0' || c == '\r')
+ return;
+ if (pri != -1 && pri != lastpri) {
+ if (dangling) {
+ msgaddchar('\n', NULL);
+ dangling = 0;
+ }
+ msgaddchar('<', NULL);
+ for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;)
+ msgaddchar(*p--, NULL);
+ msgaddchar('>', NULL);
+ lastpri = pri;
+ }
+ msgaddchar(c, NULL);
+ if (c == '\n') {
+ dangling = 0;
+ lastpri = -1;
+ } else {
+ dangling = 1;
+ }
+}
+
+/*
+ * Put char in log buffer
+ */
+static void
+msgaddchar(int c, void *dummy)
+{
+ struct msgbuf *mbp;
+
+ if (!msgbufmapped)
+ return;
+ mbp = msgbufp;
+ mbp->msg_ptr[mbp->msg_bufx++] = c;
+ if (mbp->msg_bufx >= mbp->msg_size)
+ mbp->msg_bufx = 0;
+ /* If the buffer is full, keep the most recent data. */
+ if (mbp->msg_bufr == mbp->msg_bufx) {
+ if (++mbp->msg_bufr >= mbp->msg_size)
+ mbp->msg_bufr = 0;
+ }
+}
+
+static void
+msgbufcopy(struct msgbuf *oldp)
+{
+ int pos;
+
+ pos = oldp->msg_bufr;
+ while (pos != oldp->msg_bufx) {
+ msglogchar(oldp->msg_ptr[pos], -1);
+ if (++pos >= oldp->msg_size)
+ pos = 0;
+ }
+}
+
+void
+msgbufinit(void *ptr, size_t size)
+{
+ char *cp;
+ static struct msgbuf *oldp = NULL;
+
+ size -= sizeof(*msgbufp);
+ cp = (char *)ptr;
+ msgbufp = (struct msgbuf *) (cp + size);
+ if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
+ msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
+ bzero(cp, size);
+ bzero(msgbufp, sizeof(*msgbufp));
+ msgbufp->msg_magic = MSG_MAGIC;
+ msgbufp->msg_size = (char *)msgbufp - cp;
+ }
+ msgbufp->msg_ptr = cp;
+ if (msgbufmapped && oldp != msgbufp)
+ msgbufcopy(oldp);
+ msgbufmapped = 1;
+ oldp = msgbufp;
+}
+
+SYSCTL_DECL(_security_bsd);
+
+static int unprivileged_read_msgbuf = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
+ CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
+ "Unprivileged processes may read the kernel message buffer");
+
+/* Sysctls for accessing/clearing the msgbuf */
+static int
+sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
+{
+ int error;
+
+ if (!unprivileged_read_msgbuf) {
+ error = suser(req->td);
+ if (error)
+ return (error);
+ }
+
+ /*
+ * Unwind the buffer, so that it's linear (possibly starting with
+ * some initial nulls).
+ */
+ error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
+ msgbufp->msg_size - msgbufp->msg_bufx, req);
+ if (error)
+ return (error);
+ if (msgbufp->msg_bufx > 0) {
+ error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
+ msgbufp->msg_bufx, req);
+ }
+ return (error);
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
+ 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
+
+static int msgbuf_clear;
+
+static int
+sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
+{
+ int error;
+ error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
+ if (!error && req->newptr) {
+ /* Clear the buffer and reset write pointer */
+ bzero(msgbufp->msg_ptr, msgbufp->msg_size);
+ msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
+ msgbuf_clear = 0;
+ }
+ return (error);
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
+ CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
+ sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
+
+#include "opt_ddb.h"
+#ifdef DDB
+#include <ddb/ddb.h>
+
+DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
+{
+ int i, j;
+
+ if (!msgbufmapped) {
+ db_printf("msgbuf not mapped yet\n");
+ return;
+ }
+ db_printf("msgbufp = %p\n", msgbufp);
+ db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
+ msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
+ msgbufp->msg_bufx, msgbufp->msg_ptr);
+ for (i = 0; i < msgbufp->msg_size; i++) {
+ j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
+ db_printf("%c", msgbufp->msg_ptr[j]);
+ }
+ db_printf("\n");
+}
+
+#endif /* DDB */
OpenPOWER on IntegriCloud