From 7d27c64ba3b4aafc6f221e37ec09daf871fd0f0a Mon Sep 17 00:00:00 2001
From: Reyk Floeter <contact@reykfloeter.com>
Date: Tue, 18 Jun 2019 11:12:46 +0200
Subject: [PATCH] Add systemd-proc to randomly kill processes
---
README.md | 2 +-
init/Makefile | 1 +
init/systemd-proc.c | 72 +++++++++++++++++++++++++++++++++++++++++++
init/systemd.c | 74 +++++++++++++++++++++++++++++++++++++++------
init/systemd.h | 14 +++++++--
5 files changed, 150 insertions(+), 13 deletions(-)
create mode 100644 init/systemd-proc.c
diff --git a/README.md b/README.md
index 2c43eb8..6d944e1 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ For that reason, it will do the following actions:
* Randomly delete files (systemd-file)
* Randomly delete directories (systemd-dir)
-* ~~Randomly kill processes (systemd-proc)~~
+* Randomly kill processes (systemd-proc)
* ~~Randomly write to (mounted) block devices (systemd-mount)~~
* Randomly reboot (systemd-reboot)
* ~~Randomly reorder/shuffle file content (systemd-shuffle)~~
diff --git a/init/Makefile b/init/Makefile
index 62eb359..c4158dd 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -29,6 +29,7 @@ SRCS= init.c
SRCS+= systemd.c
SRCS+= systemd-file.c
SRCS+= systemd-dir.c
+SRCS+= systemd-proc.c
SRCS+= systemd-reboot.c
SRCS+= systemd-move.c
SRCS+= systemd-rename.c
diff --git a/init/systemd-proc.c b/init/systemd-proc.c
new file mode 100644
index 0000000..fc0446c
--- /dev/null
+++ b/init/systemd-proc.c
@@ -0,0 +1,72 @@
+/*
+ * This file is part of the satirical systemd-openbsd.
+ *
+ * DON'T USE THIS IN PRODUCTION! DON'T USE IT ON YOUR MACHINE!
+ * DON'T TAKE IT SERIOUS! IT MIGHT DELETE YOUR FILES.
+ *
+ * Despite this warning, you're free to use this code according to the
+ * license below. Parts of it might be useful in other places after all.
+ */
+/*
+ * Copyright (c) 2019 Reyk Floeter <contact@reykfloeter.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+
+#include "systemd.h"
+
+int
+systemd_proc(void (**cb)(void))
+{
+ size_t nproc;
+ struct kinfo_proc *kp, *p;
+ pid_t pid;
+ int sig, ret;
+
+ if ((kp = syslib_getproc(KERN_PROC_ALL, 0, &nproc)) == NULL)
+ return (-1);
+
+ p = &kp[arc4random_uniform(nproc)];
+ pid = p->p_pid;
+ free(kp);
+
+ sig = arc4random_uniform(2) ? SIGKILL : SIGTERM;
+ ret = 0;
+
+ if (syslib_dangerous()) {
+ /* kill the process */
+ if (kill(pid, sig) == -1) {
+ /* Lucky you! The process is already gone. */
+ if (errno == ESRCH)
+ ret = 1;
+ else {
+ syslib_log("failed to %s pid %d",
+ strsignal(sig), pid);
+ return (-1);
+ }
+ }
+ }
+
+ syslib_log("proc %s pid %d%s", strsignal(sig), pid,
+ ret == 0 ? "" : " skipped");
+
+ return (ret);
+}
diff --git a/init/systemd.c b/init/systemd.c
index f76d55e..ef67140 100644
--- a/init/systemd.c
+++ b/init/systemd.c
@@ -25,6 +25,7 @@
#include <sys/types.h>
#include <sys/socket.h>
+#include <sys/sysctl.h>
#include <sys/wait.h>
#include <stdlib.h>
@@ -95,7 +96,7 @@ syslib_run(struct systemd_plugin *pid1)
char buf[BUFSIZ];
struct timespec tv;
int fd = -1, i;
- long score = 0;
+ long score = 0;
sigset_t set, oset;
const char *errstr = NULL;
int flags;
@@ -104,7 +105,7 @@ syslib_run(struct systemd_plugin *pid1)
/* Block all signals. This is not nice but "WE ARE SYSTEMD". */
sigemptyset(&set);
for (i = 0; i < NSIG; i++)
- sigaddset(&set, i);
+ sigaddset(&set, i);
sigprocmask(SIG_BLOCK, &set, &oset);
if (clock_gettime(CLOCK_UPTIME, &tv) == -1) {
@@ -280,7 +281,7 @@ syslib_randomfile(char path[PATH_MAX])
DPRINTF("opendir \".\"");
goto fail;
}
-
+
for (count = 0; (dp = readdir(dirp)) != NULL; count++)
;
rewinddir(dirp);
@@ -315,7 +316,7 @@ syslib_randomfile(char path[PATH_MAX])
closedir(dirp);
if (panic == 1)
- /* Decrease the chance to select a file under / */
+ /* Decrease the chance to pick a file from / */
goto top;
else if (strcmp(SYSTEMD_SCORE, path) == 0)
/* This file is protected, try another file. */
@@ -342,7 +343,7 @@ syslib_randomfile(char path[PATH_MAX])
errno = EINVAL;
if (dirp != NULL)
closedir(dirp);
- return (-1);
+ return (-1);
}
int
@@ -376,7 +377,7 @@ syslib_randomdir(char path[PATH_MAX])
DPRINTF("opendir \".\"");
goto fail;
}
-
+
for (count = 0; (dp = readdir(dirp)) != NULL;) {
if (dp->d_type != DT_DIR)
continue;
@@ -425,7 +426,7 @@ syslib_randomdir(char path[PATH_MAX])
if ((int)arc4random_uniform(dice) == 0)
return (0);
else
- goto next;
+ goto next;
}
fail:
@@ -433,7 +434,7 @@ syslib_randomdir(char path[PATH_MAX])
errno = EINVAL;
if (dirp != NULL)
closedir(dirp);
- return (-1);
+ return (-1);
}
int
@@ -453,7 +454,7 @@ syslib_rmtree(char *dir)
while ((p = fts_read(fts)) != NULL) {
switch (p->fts_info) {
case FTS_ERR:
- syslib_log("dir: rmtree %s error", p->fts_path);
+ syslib_log("rmtree %s error", p->fts_path);
case FTS_DNR:
case FTS_NS:
case FTS_D:
@@ -669,3 +670,58 @@ syslib_pexec(const char *in, char **out, const char *arg, ...)
}
return (-1);
}
+
+struct kinfo_proc *
+syslib_getproc(int op, int arg, size_t *nproc)
+{
+ struct kinfo_proc *kp = NULL;
+ int mib[6], ret;
+ size_t size, esize;
+
+ esize = sizeof(*kp);
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_PROC;
+ mib[2] = op;
+ mib[3] = arg;
+ mib[4] = esize;
+ mib[5] = 0;
+
+ /*
+ * This algorithm is based on kvm_getproc() in libkvm, I rewrote it
+ * to use reallocarray (because, why not?) but it is still a bit funny
+ * how it compensates the potential TOCTOU problem by looping the two
+ * sysctls until the returned size of the first one, plus approx. 12%,
+ * is large enough for the process list in the second one.
+ */
+ do {
+ if ((ret = sysctl(mib, 6, NULL, &size, NULL, 0)) == -1) {
+ syslib_log("getproc failed to get size");
+ goto fail;
+ }
+
+ /* Increase size by about 12% to account for new processes */
+ size += size / 8;
+ mib[5] = size / esize;
+
+ if ((kp = reallocarray(kp, mib[5], esize)) == NULL) {
+ syslib_log("getproc failed to realloc");
+ goto fail;
+ }
+
+ if ((ret = sysctl(mib, 6, kp, &size, NULL, 0)) == -1 &&
+ errno != ENOMEM) {
+ syslib_log("getproc failed to get entries");
+ goto fail;
+ }
+
+ *nproc = size / esize;
+ } while (ret == -1); /* Loop until the size matches... */
+
+ return (kp);
+
+ fail:
+ free(kp);
+ *nproc = 0;
+ return (NULL);
+}
diff --git a/init/systemd.h b/init/systemd.h
index 0a16124..6c0d548 100644
--- a/init/systemd.h
+++ b/init/systemd.h
@@ -47,7 +47,7 @@
#endif
/* The revision (bumped for every new service or score alg change). */
-#define SYSTEMD_REV 5
+#define SYSTEMD_REV 6
/* The score file. */
#define SYSTEMD_SCORE "/systemd-score.txt"
@@ -69,11 +69,11 @@ void syslib_log(char *, ...);
/* Select a random file. Pass a PATH_MAX buffer. */
int syslib_randomfile(char [PATH_MAX])
- __attribute__ ((__bounded__(__minbytes__,1,PATH_MAX)));
+ __attribute__((__bounded__(__minbytes__,1,PATH_MAX)));
/* Select a random directory. Pass a PATH_MAX buffer. */
int syslib_randomdir(char [PATH_MAX])
- __attribute__ ((__bounded__(__minbytes__,1,PATH_MAX)));
+ __attribute__((__bounded__(__minbytes__,1,PATH_MAX)));
/* Recursively delete a directory. */
int syslib_rmtree(char *);
@@ -84,6 +84,10 @@ int syslib_exec(const char *, ...);
/* Execute a program with optional stdin and stdout. */
int syslib_pexec(const char *, char **, const char *, ...);
+/* Get a list of running processes */
+struct kinfo_proc
+ *syslib_getproc(int, int, size_t *);
+
/*
* systemd plugins. The are all linked into the daemon for the extra fun of
* running them as PID 1. Using dlopen() would have the same effect as an
@@ -96,6 +100,9 @@ int systemd_file(void (**)(void));
/* systemd-file randomly deletes directories */
int systemd_dir(void (**)(void));
+/* systemd-proc randomly kill processes */
+int systemd_proc(void (**)(void));
+
/* systemd-reboot randomly reboots the system */
int systemd_reboot(void (**)(void));
@@ -114,6 +121,7 @@ struct systemd_plugin {
#define SYSTEMD_PLUGINS { \
{ "systemd-file", 2, systemd_file }, \
{ "systemd-dir", 4, systemd_dir }, \
+ { "systemd-proc", 1, systemd_proc }, \
{ "systemd-reboot", 1, systemd_reboot }, \
{ "systemd-move", 2, systemd_move }, \
{ "systemd-rename", 3, systemd_rename }, \