Merge projects/enhanced_coredumps (r204346) into HEAD:

  Enhanced process coredump routines.

  This brings in the following features:
  1) Limit number of cores per process via the %I coredump formatter.
  Example:
    if corefilename is set to %N.%I.core AND num_cores = 3, then
    if a process "rpd" cores, then the corefile will be named
    "rpd.0.core", however if it cores again, then the kernel will
    generate "rpd.1.core" until we hit the limit of "num_cores".

    this is useful to get several corefiles, but also prevent filling
    the machine with corefiles.

  2) Encode machine hostname in core dump name via %H.

  3) Compress coredumps, useful for embedded platforms with limited space.
    A sysctl kern.compress_user_cores is made available if turned on.

    To enable compressed coredumps, the following config options need to be set:
    options COMPRESS_USER_CORES
    device zlib   # brings in the zlib requirements.
    device gzio   # brings in the kernel vnode gzip output module.

  4) Eventhandlers are fired to indicate coredumps in progress.

  5) The imgact sv_coredump routine has grown a flag to pass in more
  state, currently this is used only for passing a flag down to compress
  the coredump or not.

  Note that the gzio facility can be used for generic output of gzip'd
  streams via vnodes.

Obtained from: Juniper Networks
Reviewed by: kan

1 files changed, 406 insertions, 0 deletions

diff --git a/sys/kern/kern_gzio.c b/sys/kern/kern_gzio.c
new file mode 100644
index 0000000..1f9c387
--- /dev/null
+++ b/sys/kern/kern_gzio.c
@@ -0,0 +1,406 @@
+/*
+ * $Id: kern_gzio.c,v 1.6 2008-10-18 22:54:45 lbazinet Exp $
+ *
+ * core_gzip.c -- gzip routines used in compressing user process cores
+ *
+ * This file is derived from src/lib/libz/gzio.c in FreeBSD.
+ */
+
+/* gzio.c -- IO on .gz files
+ * Copyright (C) 1995-1998 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ */
+
+/* @(#) $FreeBSD$ */
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/malloc.h>
+#include <sys/vnode.h>
+#include <sys/syslog.h>
+#include <sys/endian.h>
+#include <net/zutil.h>
+#include <sys/libkern.h>
+
+#include <sys/vnode.h>
+#include <sys/mount.h>
+
+#define GZ_HEADER_LEN	10
+
+#ifndef Z_BUFSIZE
+#  ifdef MAXSEG_64K
+#    define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */
+#  else
+#    define Z_BUFSIZE 16384
+#  endif
+#endif
+#ifndef Z_PRINTF_BUFSIZE
+#  define Z_PRINTF_BUFSIZE 4096
+#endif
+
+#define ALLOC(size) malloc(size, M_TEMP, M_WAITOK | M_ZERO)
+#define TRYFREE(p) {if (p) free(p, M_TEMP);}
+
+static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
+
+/* gzip flag byte */
+#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
+#define HEAD_CRC     0x02 /* bit 1 set: header CRC present */
+#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
+#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
+#define COMMENT      0x10 /* bit 4 set: file comment present */
+#define RESERVED     0xE0 /* bits 5..7: reserved */
+
+typedef struct gz_stream {
+    z_stream stream;
+    int      z_err;   /* error code for last stream operation */
+    int      z_eof;   /* set if end of input file */
+    struct vnode *file; /* vnode pointer of .gz file */
+    Byte     *inbuf;  /* input buffer */
+    Byte     *outbuf; /* output buffer */
+    uLong    crc;     /* crc32 of uncompressed data */
+    char     *msg;    /* error message */
+    char     *path;   /* path name for debugging only */
+    int      transparent; /* 1 if input file is not a .gz file */
+    char     mode;    /* 'w' or 'r' */
+    long     startpos; /* start of compressed data in file (header skipped) */
+    off_t    outoff;  /* current offset in output file */
+    int	     flags;
+} gz_stream;
+
+
+local int do_flush        OF((gzFile file, int flush));
+local int    destroy      OF((gz_stream *s));
+local void   putU32      OF((gz_stream *file, uint32_t x));
+local void *gz_alloc      OF((void *notused, u_int items, u_int size));
+local void gz_free        OF((void *notused, void *ptr));
+
+/* ===========================================================================
+     Opens a gzip (.gz) file for reading or writing. The mode parameter
+   is as in fopen ("rb" or "wb"). The file is given either by file descriptor
+   or path name (if fd == -1).
+     gz_open return NULL if the file could not be opened or if there was
+   insufficient memory to allocate the (de)compression state; errno
+   can be checked to distinguish the two cases (if errno is zero, the
+   zlib error is Z_MEM_ERROR).
+*/
+gzFile gz_open (path, mode, vp)
+    const char *path;
+    const char *mode;
+    struct vnode *vp;
+{
+    int err;
+    int level = Z_DEFAULT_COMPRESSION; /* compression level */
+    int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */
+    const char *p = mode;
+    gz_stream *s;
+    char fmode[80]; /* copy of mode, without the compression level */
+    char *m = fmode;
+    int resid;
+    int error;
+    char buf[GZ_HEADER_LEN + 1];
+
+    if (!path || !mode) return Z_NULL;
+
+    s = (gz_stream *)ALLOC(sizeof(gz_stream));
+    if (!s) return Z_NULL;
+
+    s->stream.zalloc = (alloc_func)gz_alloc;
+    s->stream.zfree = (free_func)gz_free;
+    s->stream.opaque = (voidpf)0;
+    s->stream.next_in = s->inbuf = Z_NULL;
+    s->stream.next_out = s->outbuf = Z_NULL;
+    s->stream.avail_in = s->stream.avail_out = 0;
+    s->file = NULL;
+    s->z_err = Z_OK;
+    s->z_eof = 0;
+    s->crc = 0;
+    s->msg = NULL;
+    s->transparent = 0;
+    s->outoff = 0;
+    s->flags = 0;
+
+    s->path = (char*)ALLOC(strlen(path)+1);
+    if (s->path == NULL) {
+        return destroy(s), (gzFile)Z_NULL;
+    }
+    strcpy(s->path, path); /* do this early for debugging */
+
+    s->mode = '\0';
+    do {
+        if (*p == 'r') s->mode = 'r';
+        if (*p == 'w' || *p == 'a') s->mode = 'w';
+        if (*p >= '0' && *p <= '9') {
+	    level = *p - '0';
+	} else if (*p == 'f') {
+	  strategy = Z_FILTERED;
+	} else if (*p == 'h') {
+	  strategy = Z_HUFFMAN_ONLY;
+	} else {
+	    *m++ = *p; /* copy the mode */
+	}
+    } while (*p++ && m != fmode + sizeof(fmode));
+
+    if (s->mode != 'w') {
+        log(LOG_ERR, "gz_open: mode is not w (%c)\n", s->mode);
+        return destroy(s), (gzFile)Z_NULL;
+    }
+    
+    err = deflateInit2(&(s->stream), level,
+                       Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy);
+    /* windowBits is passed < 0 to suppress zlib header */
+
+    s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
+    if (err != Z_OK || s->outbuf == Z_NULL) {
+        return destroy(s), (gzFile)Z_NULL;
+    }
+
+    s->stream.avail_out = Z_BUFSIZE;
+    s->file = vp;
+
+    /* Write a very simple .gz header:
+     */
+    snprintf(buf, sizeof(buf), "%c%c%c%c%c%c%c%c%c%c", gz_magic[0],
+             gz_magic[1], Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/,
+             0 /*xflags*/, OS_CODE);
+
+    if ((error = vn_rdwr(UIO_WRITE, s->file, buf, GZ_HEADER_LEN, s->outoff,
+                         UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, curproc->p_ucred,
+                         NOCRED, &resid, curthread))) {
+        s->outoff += GZ_HEADER_LEN - resid;
+        return destroy(s), (gzFile)Z_NULL;
+    }
+    s->outoff += GZ_HEADER_LEN;
+    s->startpos = 10L;
+    
+    return (gzFile)s;
+}
+
+
+ /* ===========================================================================
+ * Cleanup then free the given gz_stream. Return a zlib error code.
+   Try freeing in the reverse order of allocations.
+ */
+local int destroy (s)
+    gz_stream *s;
+{
+    int err = Z_OK;
+
+    if (!s) return Z_STREAM_ERROR;
+
+    TRYFREE(s->msg);
+
+    if (s->stream.state != NULL) {
+	if (s->mode == 'w') {
+	    err = deflateEnd(&(s->stream));
+	}
+    }
+    if (s->z_err < 0) err = s->z_err;
+
+    TRYFREE(s->inbuf);
+    TRYFREE(s->outbuf);
+    TRYFREE(s->path);
+    TRYFREE(s);
+    return err;
+}
+
+
+/* ===========================================================================
+     Writes the given number of uncompressed bytes into the compressed file.
+   gzwrite returns the number of bytes actually written (0 in case of error).
+*/
+int ZEXPORT gzwrite (file, buf, len)
+    gzFile file;
+    const voidp buf;
+    unsigned len;
+{
+    gz_stream *s = (gz_stream*)file;
+    off_t curoff;
+    size_t resid;
+    int error;
+    int vfslocked;
+
+    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+    s->stream.next_in = (Bytef*)buf;
+    s->stream.avail_in = len;
+
+    curoff = s->outoff;
+    while (s->stream.avail_in != 0) {
+
+        if (s->stream.avail_out == 0) {
+
+            s->stream.next_out = s->outbuf;
+            vfslocked = VFS_LOCK_GIANT(s->file->v_mount);
+            error = vn_rdwr_inchunks(UIO_WRITE, s->file, s->outbuf, Z_BUFSIZE,
+                        curoff, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT,
+                        curproc->p_ucred, NOCRED, &resid, curthread);
+            VFS_UNLOCK_GIANT(vfslocked);
+            if (error) {
+                log(LOG_ERR, "gzwrite: vn_rdwr return %d\n", error);
+                curoff += Z_BUFSIZE - resid;
+                s->z_err = Z_ERRNO;
+                break;
+            }
+            curoff += Z_BUFSIZE;
+            s->stream.avail_out = Z_BUFSIZE;
+        }
+        s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
+        if (s->z_err != Z_OK) {
+            log(LOG_ERR,
+                "gzwrite: deflate returned error %d\n", s->z_err);
+            break;
+        }
+    }
+
+    s->crc = ~crc32_raw(buf, len, ~s->crc);
+    s->outoff = curoff;
+
+    return (int)(len - s->stream.avail_in);
+}
+
+
+/* ===========================================================================
+     Flushes all pending output into the compressed file. The parameter
+   flush is as in the deflate() function.
+*/
+local int do_flush (file, flush)
+    gzFile file;
+    int flush;
+{
+    uInt len;
+    int done = 0;
+    gz_stream *s = (gz_stream*)file;
+    off_t curoff = s->outoff;
+    size_t resid;
+    int vfslocked = 0;
+    int error;
+
+    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+    if (s->stream.avail_in) {
+        log(LOG_WARNING, "do_flush: avail_in non-zero on entry\n");
+    } 
+
+    s->stream.avail_in = 0; /* should be zero already anyway */
+
+    for (;;) {
+        len = Z_BUFSIZE - s->stream.avail_out;
+
+        if (len != 0) {
+            vfslocked = VFS_LOCK_GIANT(s->file->v_mount);
+            error = vn_rdwr_inchunks(UIO_WRITE, s->file, s->outbuf, len, curoff,
+                        UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, curproc->p_ucred,
+                        NOCRED, &resid, curthread);
+            VFS_UNLOCK_GIANT(vfslocked);
+	    if (error) {
+                s->z_err = Z_ERRNO;
+                s->outoff = curoff + len - resid;
+                return Z_ERRNO;
+            }
+            s->stream.next_out = s->outbuf;
+            s->stream.avail_out = Z_BUFSIZE;
+            curoff += len;
+        }
+        if (done) break;
+        s->z_err = deflate(&(s->stream), flush);
+
+	/* Ignore the second of two consecutive flushes: */
+	if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK;
+
+        /* deflate has finished flushing only when it hasn't used up
+         * all the available space in the output buffer: 
+         */
+        done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
+ 
+        if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
+    }
+    s->outoff = curoff;
+
+    return  s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
+}
+
+int ZEXPORT gzflush (file, flush)
+     gzFile file;
+     int flush;
+{
+    gz_stream *s = (gz_stream*)file;
+    int err = do_flush (file, flush);
+
+    if (err) return err;
+    return  s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
+}
+
+
+/* ===========================================================================
+   Outputs a long in LSB order to the given file
+*/
+local void putU32 (s, x)
+    gz_stream *s;
+    uint32_t x;
+{
+    uint32_t xx;
+    off_t curoff = s->outoff;
+    int resid;
+
+#if BYTE_ORDER == BIG_ENDIAN
+    xx = bswap32(x);
+#else
+    xx = x;
+#endif
+    vn_rdwr(UIO_WRITE, s->file, (caddr_t)&xx, sizeof(xx), curoff,
+            UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, curproc->p_ucred,
+            NOCRED, &resid, curthread);
+    s->outoff += sizeof(xx) - resid;
+}
+
+
+/* ===========================================================================
+     Flushes all pending output if necessary, closes the compressed file
+   and deallocates all the (de)compression state.
+*/
+int ZEXPORT gzclose (file)
+    gzFile file;
+{
+    int err;
+    gz_stream *s = (gz_stream*)file;
+
+    if (s == NULL) return Z_STREAM_ERROR;
+
+    if (s->mode == 'w') {
+        err = do_flush (file, Z_FINISH);
+        if (err != Z_OK) {
+            log(LOG_ERR, "gzclose: do_flush failed (err %d)\n", err);
+            return destroy((gz_stream*)file);
+        }
+#if 0
+	printf("gzclose: putting crc: %lld total: %lld\n",
+	    (long long)s->crc, (long long)s->stream.total_in);
+	printf("sizeof uLong = %d\n", (int)sizeof(uLong));
+#endif
+        putU32 (s, s->crc);
+        putU32 (s, (uint32_t) s->stream.total_in);
+    }
+    return destroy((gz_stream*)file);
+}
+
+/*
+ * Space allocation and freeing routines for use by zlib routines when called
+ * from gzip modules.
+ */
+static void *
+gz_alloc(void *notused __unused, u_int items, u_int size)
+{
+    void *ptr;
+
+    MALLOC(ptr, void *, items * size, M_TEMP, M_NOWAIT | M_ZERO);
+    return ptr;
+}
+                                     
+static void
+gz_free(void *opaque __unused, void *ptr)
+{
+    FREE(ptr, M_TEMP);
+}
+