[systemd-devel] [PATCH] [RFC] Optionaly save coredump to file
Oleksii Shevchuk
alxchk at gmail.com
Fri Feb 8 14:47:05 PST 2013
Dump coredump to /var/log/journal/MACHINE-ID/coredump/COMM.DUMP-ID128.
If can't, fallback to default behavior (dump to journal 24Mb of data).
Optionaly introduce SHA1 hashsum for incoming coredumps, if they are
going out of journal
---
Makefile.am | 10 ++
src/journal/coredump.c | 263 +++++++++++++++++++++++++++++++-----------
src/journal/journald-server.h | 2 +-
src/shared/util.c | 23 ++++
src/shared/util.h | 1 +
5 files changed, 232 insertions(+), 67 deletions(-)
diff --git a/Makefile.am b/Makefile.am
index 163e8f8..8cf3686 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2644,6 +2644,7 @@ systemd_coredump_SOURCES = \
systemd_coredump_LDADD = \
libsystemd-journal-internal.la \
+ libsystemd-id128-internal.la \
libsystemd-label.la \
libsystemd-shared.la
@@ -2652,6 +2653,15 @@ systemd_coredump_LDADD += \
libsystemd-login-internal.la
endif
+if HAVE_GCRYPT
+systemd_coredump_CFLAGS = \
+ $(GCRYPT_CFLAGS) \
+ -Wno-pointer-arith
+
+systemd_coredump_LDADD += \
+ $(GCRYPT_LIBS)
+endif
+
rootlibexec_PROGRAMS += \
systemd-coredump
diff --git a/src/journal/coredump.c b/src/journal/coredump.c
index 021b4c6..06fad24 100644
--- a/src/journal/coredump.c
+++ b/src/journal/coredump.c
@@ -24,6 +24,10 @@
#include <stdio.h>
#include <sys/prctl.h>
+#if defined(HAVE_GCRYPT)
+#include <gcrypt.h>
+#endif
+
#include <systemd/sd-journal.h>
#ifdef HAVE_LOGIND
@@ -35,6 +39,7 @@
#include "macro.h"
#include "mkdir.h"
#include "special.h"
+#include "sd-id128.h"
#include "cgroup-util.h"
#define COREDUMP_MAX (24*1024*1024)
@@ -49,61 +54,215 @@ enum {
_ARG_MAX
};
-static int divert_coredump(void) {
- _cleanup_fclose_ FILE *f = NULL;
+#if defined(HAVE_GCRYPT)
+static void gcry_md_closep(gcry_md_hd_t *p)
+{
+ gcry_md_close(*p);
+}
+#endif
+
+static int submit_process_core(struct iovec iovec[15], int idx,
+ const char * comm,
+ const int journal)
+{
+ int r = EXIT_FAILURE;
- log_info("Detected coredump of the journal daemon itself, diverting coredump to /var/lib/systemd/coredump/.");
+ _cleanup_fclose_ FILE * corefile = NULL;
+ _cleanup_free_ char * corepath = NULL;
+ _cleanup_free_ char * corelink = NULL;
+ _cleanup_free_ char * t = NULL;
- mkdir_p_label("/var/lib/systemd/coredump", 0755);
+#if defined(HAVE_GCRYPT)
+ _cleanup_free_ char * h = NULL;
+#endif
- f = fopen("/var/lib/systemd/coredump/core.systemd-journald", "we");
- if (!f) {
- log_error("Failed to create coredump file: %m");
- return -errno;
+ if (journal) {
+ mkdir_p_label("/var/lib/systemd/coredump", 0755);
+ corelink = strdup("/var/lib/systemd/coredump/core.systemd-journald");
+ if (! corelink) {
+ r = log_oom();
+ goto finish;
+ }
+
+ corepath = strdup(corelink);
+ if (! corepath) {
+ r = log_oom();
+ goto finish;
+ }
+ } else {
+ _cleanup_free_ char * c;
+
+ char buffer[33];
+ sd_id128_t coreid;
+ sd_id128_t machineid;
+
+ const char *p = strrchr(comm, '/');
+ if (p)
+ p ++;
+ else
+ p = comm;
+
+ r = sd_id128_get_machine(&machineid);
+ if (r)
+ goto finish;
+
+ c = sd_id128_to_string(machineid, buffer);
+ c = strjoin("/var/log/journal/", c, "/coredump", NULL);
+ if (! c)
+ goto finish;
+
+ r = access(c, X_OK | W_OK);
+ if (r)
+ goto finish;
+
+ r = sd_id128_randomize(&coreid);
+ if (r)
+ goto finish;
+
+ corelink = strjoin(p, ".", sd_id128_to_string(coreid, buffer), NULL);
+ if (! corelink)
+ goto finish;
+
+ corepath = strjoin(c, "/", corelink, NULL);
+ if (! corepath)
+ goto finish;
}
- for (;;) {
- uint8_t buffer[4096];
- size_t l, q;
+ corefile = fopen(corepath, "w");
+
+ if (! corefile) {
+ if (journal) {
+ log_error("Failed to create coredump file: %m");
+ goto finish;
+ }
+ else {
+ int n;
+
+ IOVEC_SET_STRING(iovec[idx++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
+
+ t = malloc(9 + COREDUMP_MAX);
+ if (!t) {
+ r = log_oom();
+ goto finish;
+ }
+
+ memcpy(t, "COREDUMP=", 9);
- l = fread(buffer, 1, sizeof(buffer), stdin);
- if (l <= 0) {
- if (ferror(f)) {
- log_error("Failed to read coredump: %m");
- return -errno;
+ n = loop_read(STDIN_FILENO, t + 9, COREDUMP_MAX, false);
+ if (n < 0) {
+ log_error("Failed to read core dump data: %s", strerror(-n));
+ r = (int) n;
+ goto finish;
}
- break;
+ iovec[idx].iov_base = t;
+ iovec[idx].iov_len = 9 + n;
+ idx ++;
+ }
+ }
+ else {
+ r = chmod(corepath, 0600);
+ if (r) {
+ log_debug("chmod %s: %s", corepath, strerror(errno));
+ }
+
+#if defined(HAVE_GCRYPT)
+ /* initialize_libgcrypt(); */
+
+ __attribute__((cleanup(gcry_md_closep)))
+ gcry_md_hd_t HD;
+ gcry_error_t gr = gcry_md_open (&HD, GCRY_MD_SHA1, 0);
+ if (gr != GPG_ERR_NO_ERROR) {
+ log_error("Failed to initialize gcrypt hash context: %s",
+ gpg_strerror(gr));
+ goto finish;
}
+#endif
+ for (;;) {
+ uint8_t buffer[4096];
+ size_t l, q;
+
+ l = fread(buffer, 1, sizeof(buffer), stdin);
+ if (l <= 0) {
+ if (ferror(corefile)) {
+ log_error("Failed to read coredump: %m");
+ goto finish;
+ }
+
+ break;
+ }
- q = fwrite(buffer, 1, l, f);
- if (q != l) {
+ q = fwrite(buffer, 1, l, corefile);
+ if (q != l) {
+ log_error("Failed to write coredump: %m");
+ goto finish;
+ }
+
+#if defined(HAVE_GCRYPT)
+ gcry_md_write(HD, buffer, l);
+#endif
+ }
+
+ fflush(corefile);
+
+ if (ferror(corefile)) {
log_error("Failed to write coredump: %m");
- return -errno;
}
- }
- fflush(f);
+ IOVEC_SET_STRING(iovec[idx++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b2");
+
+ if (journal) {
+ log_error("Detected coredump of the journal daemon itself, coredump diverted to /var/lib/systemd/coredump/");
+ r = EXIT_SUCCESS;
+ goto finish;
+ }
+
+ t = strjoin("COREDUMP_FILE=coredump/", corelink, NULL);
+ if (t)
+ IOVEC_SET_STRING(iovec[idx ++], t);
- if (ferror(f)) {
- log_error("Failed to write coredump: %m");
- return -errno;
+#if defined(HAVE_GCRYPT)
+ char * bh = hexstr(gcry_md_read(HD, GCRY_MD_SHA1), 20);
+
+ if (! bh) {
+ r = log_oom();
+ goto finish;
+ }
+
+ h = strjoin("COREDUMP_FILE_SHA1=", bh, NULL);
+ free(bh);
+
+ if (! h) {
+ r = log_oom();
+ goto finish;
+ }
+
+ IOVEC_SET_STRING(iovec[idx ++], h);
+#endif
}
- return 0;
+ r = sd_journal_sendv(iovec, idx);
+ if (r < 0)
+ log_error("Failed to send coredump: %s", strerror(-r));
+
+ finish:
+ return r;
}
int main(int argc, char* argv[]) {
int r, j = 0;
+ int journal = 0;
_cleanup_free_ char *p = NULL;
- ssize_t n;
pid_t pid;
uid_t uid;
gid_t gid;
- struct iovec iovec[14];
+ struct iovec iovec[15];
_cleanup_free_ char *core_pid = NULL, *core_uid = NULL, *core_gid = NULL, *core_signal = NULL,
*core_timestamp = NULL, *core_comm = NULL, *core_exe = NULL, *core_unit = NULL,
- *core_session = NULL, *core_message = NULL, *core_cmdline = NULL, *t = NULL;
+ *core_session = NULL, *core_message = NULL, *core_cmdline = NULL,
+ *core_corelink = NULL;
+
+ char * t;
prctl(PR_SET_DUMPABLE, 0);
@@ -126,27 +285,20 @@ int main(int argc, char* argv[]) {
}
if (cg_pid_get_unit(pid, &t) >= 0) {
-
- if (streq(t, SPECIAL_JOURNALD_SERVICE)) {
- /* Make sure we don't make use of the journal,
- * if it's the journal which is crashing */
- log_set_target(LOG_TARGET_KMSG);
- log_open();
-
- r = divert_coredump();
- goto finish;
- }
-
core_unit = strappend("COREDUMP_UNIT=", t);
+ journal = streq(t, SPECIAL_JOURNALD_SERVICE);
} else if (cg_pid_get_user_unit(pid, &t) >= 0)
core_unit = strappend("COREDUMP_USER_UNIT=", t);
+ free(t);
if (core_unit)
IOVEC_SET_STRING(iovec[j++], core_unit);
- /* OK, now we know it's not the journal, hence make use of
- * it */
- log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
+ if (journal)
+ log_set_target(LOG_TARGET_KMSG);
+ else
+ log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
+
log_open();
r = parse_uid(argv[ARG_UID], &uid);
@@ -191,7 +343,6 @@ int main(int argc, char* argv[]) {
}
#endif
-
if (get_process_exe(pid, &t) >= 0) {
core_exe = strappend("COREDUMP_EXE=", t);
free(t);
@@ -212,7 +363,6 @@ int main(int argc, char* argv[]) {
if (core_timestamp)
IOVEC_SET_STRING(iovec[j++], core_timestamp);
- IOVEC_SET_STRING(iovec[j++], "MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1");
IOVEC_SET_STRING(iovec[j++], "PRIORITY=2");
core_message = strjoin("MESSAGE=Process ", argv[ARG_PID], " (", argv[ARG_COMM], ") dumped core.", NULL);
@@ -232,28 +382,9 @@ int main(int argc, char* argv[]) {
goto finish;
}
- p = malloc(9 + COREDUMP_MAX);
- if (!p) {
- r = log_oom();
- goto finish;
- }
-
- memcpy(p, "COREDUMP=", 9);
-
- n = loop_read(STDIN_FILENO, p + 9, COREDUMP_MAX, false);
- if (n < 0) {
- log_error("Failed to read core dump data: %s", strerror(-n));
- r = (int) n;
- goto finish;
- }
-
- iovec[j].iov_base = p;
- iovec[j].iov_len = 9 + n;
- j++;
-
- r = sd_journal_sendv(iovec, j);
+ r = submit_process_core(iovec, j, argv[ARG_COMM], journal);
if (r < 0)
- log_error("Failed to send coredump: %s", strerror(-r));
+ log_error("Failed to store coredump: %s", strerror(-r));
finish:
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h
index 9f50a29..3d05925 100644
--- a/src/journal/journald-server.h
+++ b/src/journal/journald-server.h
@@ -121,7 +121,7 @@ typedef struct Server {
struct udev *udev;
} Server;
-#define N_IOVEC_META_FIELDS 17
+#define N_IOVEC_META_FIELDS 18
#define N_IOVEC_KERNEL_FIELDS 64
#define N_IOVEC_UDEV_FIELDS 32
diff --git a/src/shared/util.c b/src/shared/util.c
index 969ef2b..a7eb343 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1378,6 +1378,29 @@ char hexchar(int x) {
return table[x & 15];
}
+char * hexstr (const uint8_t *in, size_t count)
+{
+ char *r, *i = NULL;
+
+ if (!in || !count)
+ goto finish;
+
+ r = i = new(char, count * 2 + 1);
+ if (! r)
+ goto finish;
+
+ while (count--) {
+ *i++ = hexchar(*in >> 4);
+ *i++ = hexchar(*in);
+ ++in;
+ }
+
+ *i = '\0';
+
+ finish:
+ return r;
+}
+
int unhexchar(char c) {
if (c >= '0' && c <= '9')
diff --git a/src/shared/util.h b/src/shared/util.h
index 223617c..32a822d 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -211,6 +211,7 @@ int get_process_uid(pid_t pid, uid_t *uid);
int get_process_gid(pid_t pid, gid_t *gid);
char hexchar(int x);
+char * hexstr (const uint8_t *in, size_t count);
int unhexchar(char c);
char octchar(int x);
int unoctchar(char c);
--
1.8.1.2
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