From 5c23331a561fdaa4b79070654462ad50a7f0b17a Mon Sep 17 00:00:00 2001
From: Colin Patrick McCabe <cmccabe@alumni.cmu.edu>
Date: Thu, 12 May 2011 17:10:59 -0700
Subject: [PATCH] Add code
Signed-off-by: Colin McCabe <colin.mccabe@dreamhost.com>
---
Makefile | 11 +++
handle_core.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 217 insertions(+), 0 deletions(-)
create mode 100644 Makefile
create mode 100644 handle_core.c
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9415613
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+CC=gcc
+
+CFLAGS=-Wall
+
+all: handle_core
+
+handle_core: handle_core.o
+ $(CC) $(CFLAGS) handle_core.o -o $@
+
+clean:
+ rm -rf *o handle_core
diff --git a/handle_core.c b/handle_core.c
new file mode 100644
index 0000000..afd6daf
--- /dev/null
+++ b/handle_core.c
@@ -0,0 +1,206 @@
+#include <ctype.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <fnmatch.h>
+#include <glob.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+
+#define BUF_SIZE 1024
+#define CORE_PATTERN "core.*"
+
+/*
+ * Core file handler
+ *
+ * Example usage:
+ * echo "|/usr/bin/handle_core -e %p -d /home/core -m 10" > \
+ * /proc/sys/kernel/core_pattern
+ */
+
+/* Count the number of core files we have. */
+static int count_core_files(const char *core_dir)
+{
+ struct dirent *de;
+ int count = 0;
+ DIR *dp = opendir(core_dir);
+ if (!dp) {
+ int err = errno;
+ return -err;
+ }
+
+ while (1) {
+ de = readdir(dp);
+ if (!de)
+ break;
+ if (fnmatch(CORE_PATTERN, de->d_name, 0) == 0) {
+ count++;
+ }
+ }
+ closedir(dp);
+ return count;
+}
+
+/* Unlink the core which sorts the first in the glob sort order. */
+static int unlink_core(const char *core_dir)
+{
+ int ret;
+ char path[PATH_MAX];
+ glob_t g;
+
+ snprintf(path, PATH_MAX, "%s/%s", core_dir, CORE_PATTERN);
+ ret = glob(path, GLOB_ERR, NULL, &g);
+ if (ret != 0) {
+ return EIO;
+ }
+ if (g.gl_pathc == 0)
+ return ENOENT;
+ if (unlink(g.gl_pathv[0])) {
+ globfree(&g);
+ return errno;
+ }
+ globfree(&g);
+ return 0;
+}
+
+/* Print the new core name into a buffer of size PATH_MAX */
+static void get_core_name(const char *core_dir, char *core_name)
+{
+ struct tm *tm;
+ struct tm tm_buf;
+ time_t now;
+ time(&now);
+ tm = localtime_r(&now, &tm_buf);
+ snprintf(core_name, PATH_MAX, "%s/core.%d-%lld-%lld_%lld", core_dir,
+ tm->tm_year, (long long)tm->tm_mon, (long long)tm->tm_mday,
+ (long long)now);
+}
+
+static void usage(void)
+{
+ fprintf(stderr, "handle_core: userspace core-file handler for Linux\n\
+-d <core_dir> Directory to write core files into\n\
+-e <executable-name> Name of the executable that is core dumping\n\
+-h This help message\n\
+-m <max_cores> This maximum number of core files to allow\n\
+ before deleting older core files.\n\
+");
+}
+
+static void parse_options(int argc, char **argv, int *max_cores,
+ char **exe_name, char **core_dir)
+{
+ int c;
+ *max_cores = 10;
+ *exe_name = NULL;
+ *core_dir = "/var/core";
+ while ((c = getopt(argc, argv, "d:hm:")) != -1) {
+ switch (c) {
+ case 'd':
+ *core_dir = optarg;
+ break;
+ case 'e':
+ *exe_name = optarg;
+ break;
+ case 'h':
+ usage();
+ exit(0);
+ break;
+ case 'm':
+ *max_cores = atoi(optarg);
+ if (*max_cores == 0) {
+ fprintf(stderr, "handle_core: invalid argument "
+ "for max_cores: %s. Please give a number "
+ "greater than 0.\n", optarg);
+ exit(1);
+ }
+ break;
+ default:
+ fprintf(stderr, "handle_core: invalid usage\n\n");
+ usage();
+ exit(1);
+ break;
+ }
+ }
+ if (*exe_name == NULL) {
+ fprintf(stderr, "handle_core: you must supply the executable "
+ "name with -e. Try -h for help.\n");
+ exit(1);
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int done = 0;
+ char *exe_name, *core_dir;
+ char core_name[PATH_MAX];
+ FILE *fp;
+ int num_coref, num_deleted;
+ int max_cores;
+
+ /* Write the core to a file */
+ parse_options(argc, argv, &max_cores, &exe_name, &core_dir);
+ get_core_name(core_dir, core_name);
+ fp = fopen(core_name, "w");
+ if (!fp) {
+ int err = errno;
+ syslog(LOG_USER | LOG_ERR, "unable to open %s: "
+ "error %d (%s)\n", core_name, err, strerror(err));
+ return err;
+ }
+ do {
+ size_t res;
+ char buf[BUF_SIZE];
+ size_t nread = fread(buf, 1, BUF_SIZE, stdin);
+ if (nread != BUF_SIZE) {
+ if (ferror(fp)) {
+ int err = errno;
+ syslog(LOG_USER | LOG_ERR, "error reading core "
+ "file from stdin: %d (%s)", err, strerror(err));
+ fclose(fp);
+ return err;
+ }
+ else {
+ done = 1;
+ }
+ }
+ res = fwrite(buf, 1, nread, fp);
+ if (res != nread) {
+ int err = errno;
+ syslog(LOG_USER | LOG_ERR, "error writing core "
+ "file to %s: %d (%s)", core_name, err, strerror(err));
+ fclose(fp);
+ return err;
+ }
+ } while (!done);
+ fclose(fp);
+
+ /* Make sure we don't have too many cores sitting around. */
+ num_coref = count_core_files(core_dir);
+ num_deleted = 0;
+ if (num_coref < 0) {
+ syslog(LOG_USER | LOG_ERR, "count_core_files failed with error "
+ "code %d\n", num_coref);
+ return num_coref;
+ }
+ while (num_coref > max_cores) {
+ int ret = unlink_core(core_dir);
+ if (ret) {
+ syslog(LOG_USER | LOG_ERR, "unlink_core failed with error "
+ "code %d\n", ret);
+ }
+ num_coref--;
+ num_deleted++;
+ }
+
+ syslog(LOG_USER | LOG_ERR, "wrote core %s. Deleted %d extra core%s\n",
+ core_name, num_deleted, ((num_deleted == 1) ? "" : "s"));
+ return 0;
+}
--
1.6.6.rc1.39.g9a42