/*
  librc-daemon
  Finds PID for given daemon criteria
*/

/*
 * Copyright (c) 2007-2009 Roy Marples <roy@marples.name>
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#include "librc.h"

#if defined(__linux__) || defined (__GLIBC__)
static bool
pid_is_exec(pid_t pid, const char *exec)
{
	char buffer[32];
	FILE *fp;
	int c;
	bool retval = false;

	exec = basename_c(exec);
	snprintf(buffer, sizeof(buffer), "/proc/%d/stat", pid);
	if ((fp = fopen(buffer, "r"))) {
		while ((c = getc(fp)) != EOF && c != '(')
			;
		if (c == '(') {
			while ((c = getc(fp)) != EOF && c == *exec)
				exec++;
			if (c == ')' && *exec == '\0')
				retval = true;
		}
		fclose(fp);
	}
	return retval;
}

static bool
pid_is_argv(pid_t pid, const char *const *argv)
{
	char cmdline[32];
	int fd;
	char buffer[PATH_MAX];
	char *p;
	ssize_t bytes;

	snprintf(cmdline, sizeof(cmdline), "/proc/%u/cmdline", pid);
	if ((fd = open(cmdline, O_RDONLY)) < 0)
		return false;
	bytes = read(fd, buffer, sizeof(buffer));
	close(fd);
	if (bytes == -1)
		return false;

	buffer[bytes] = '\0';
	p = buffer;
	while (*argv) {
		if (strcmp(*argv, p) != 0)
			return false;
		argv++;
		p += strlen(p) + 1;
		if ((unsigned)(p - buffer) > sizeof(buffer))
			return false;
	}
	return true;
}

RC_PIDLIST *
rc_find_pids(const char *exec, const char *const *argv, uid_t uid, pid_t pid)
{
	DIR *procdir;
	struct dirent *entry;
	pid_t p;
	char buffer[PATH_MAX];
	struct stat sb;
	pid_t runscript_pid = 0;
	char *pp;
	RC_PIDLIST *pids = NULL;
	RC_PID *pi;

	if ((procdir = opendir("/proc")) == NULL)
		return NULL;

	/*
	  We never match RC_RUNSCRIPT_PID if present so we avoid the below
	  scenario

	  /etc/init.d/ntpd stop does
	  start-stop-daemon --stop --name ntpd
	  catching /etc/init.d/ntpd stop

	  nasty
	*/

	if ((pp = getenv("RC_RUNSCRIPT_PID"))) {
		if (sscanf(pp, "%d", &runscript_pid) != 1)
			runscript_pid = 0;
	}

	while ((entry = readdir(procdir)) != NULL) {
		if (sscanf(entry->d_name, "%d", &p) != 1)
			continue;
		if (runscript_pid != 0 && runscript_pid == p)
			continue;
		if (pid != 0 && pid != p)
			continue;
		if (uid) {
			snprintf(buffer, sizeof(buffer), "/proc/%d", p);
			if (stat(buffer, &sb) != 0 || sb.st_uid != uid)
				continue;
		}
		if (exec && !pid_is_exec(p, exec))
			continue;
		if (argv &&
		    !pid_is_argv(p, (const char *const *)argv))
			continue;
		if (!pids) {
			pids = xmalloc(sizeof(*pids));
			LIST_INIT(pids);
		}
		pi = xmalloc(sizeof(*pi));
		pi->pid = p;
		LIST_INSERT_HEAD(pids, pi, entries);
	}
	closedir(procdir);
	return pids;
}
librc_hidden_def(rc_find_pids)

#elif BSD

# if defined(__NetBSD__) || defined(__OpenBSD__)
#  define _KVM_GETPROC2
#  define _KINFO_PROC kinfo_proc2
#  define _KVM_GETARGV kvm_getargv2
#  define _GET_KINFO_UID(kp) (kp.p_ruid)
#  define _GET_KINFO_COMM(kp) (kp.p_comm)
#  define _GET_KINFO_PID(kp) (kp.p_pid)
#  define _KVM_PATH NULL
#  define _KVM_FLAGS KVM_NO_FILES
# else
#  ifndef KERN_PROC_PROC
#    define KERN_PROC_PROC KERN_PROC_ALL
#  endif
#  define _KINFO_PROC kinfo_proc
#  define _KVM_GETARGV kvm_getargv
#  if defined(__DragonFly__)
#    define _GET_KINFO_UID(kp) (kp.kp_ruid)
#    define _GET_KINFO_COMM(kp) (kp.kp_comm)
#    define _GET_KINFO_PID(kp) (kp.kp_pid)
#  else
#    define _GET_KINFO_UID(kp) (kp.ki_ruid)
#    define _GET_KINFO_COMM(kp) (kp.ki_comm)
#    define _GET_KINFO_PID(kp) (kp.ki_pid)
#  endif
#  define _KVM_PATH _PATH_DEVNULL
#  define _KVM_FLAGS O_RDONLY
# endif

RC_PIDLIST *
rc_find_pids(const char *exec, const char *const *argv, uid_t uid, pid_t pid)
{
	static kvm_t *kd = NULL;
	char errbuf[_POSIX2_LINE_MAX];
	struct _KINFO_PROC *kp;
	int i;
	int processes = 0;
	int pargc = 0;
	char **pargv;
	RC_PIDLIST *pids = NULL;
	RC_PID *pi;
	pid_t p;
	const char *const *arg;
	int match;

	if ((kd = kvm_openfiles(_KVM_PATH, _KVM_PATH,
		    NULL, _KVM_FLAGS, errbuf)) == NULL)
	{
		fprintf(stderr, "kvm_open: %s\n", errbuf);
		return NULL;
	}

#ifdef _KVM_GETPROC2
	kp = kvm_getproc2(kd, KERN_PROC_ALL, 0, sizeof(*kp), &processes);
#else
	kp = kvm_getprocs(kd, KERN_PROC_PROC, 0, &processes);
#endif
	if ((kp == NULL && processes > 0) || (kp != NULL && processes < 0)) {
		fprintf(stderr, "kvm_getprocs: %s\n", kvm_geterr(kd));
		kvm_close(kd);
		return NULL;
	}

	if (exec)
		exec = basename_c(exec);
	for (i = 0; i < processes; i++) {
		p = _GET_KINFO_PID(kp[i]);
		if (pid != 0 && pid != p)
			continue;
		if (uid != 0 && uid != _GET_KINFO_UID(kp[i]))
			continue;
		if (exec) {
			if (!_GET_KINFO_COMM(kp[i]) ||
			    strcmp(exec, _GET_KINFO_COMM(kp[i])) != 0)
				continue;
		}
		if (argv && *argv) {
			pargv = _KVM_GETARGV(kd, &kp[i], pargc);
			if (!pargv || !*pargv)
				continue;
			arg = argv;
			match = 1;
			while (*arg && *pargv)
				if (strcmp(*arg++, *pargv++) != 0) {
					match = 0;
					break;
				}
			if (!match)
				continue;
		}
		if (!pids) {
			pids = xmalloc(sizeof(*pids));
			LIST_INIT(pids);
		}
		pi = xmalloc(sizeof(*pi));
		pi->pid = p;
		LIST_INSERT_HEAD(pids, pi, entries);
	}
	kvm_close(kd);

	return pids;
}
librc_hidden_def(rc_find_pids)

#else
#  error "Platform not supported!"
#endif

static bool
_match_daemon(const char *path, const char *file, RC_STRINGLIST *match)
{
	char *line = NULL;
	size_t len = 0;
	char ffile[PATH_MAX];
	FILE *fp;
	RC_STRING *m;

	snprintf(ffile, sizeof(ffile), "%s/%s", path, file);
	fp = fopen(ffile, "r");

	if (!fp)
		return false;

	while ((rc_getline(&line, &len, fp))) {
		TAILQ_FOREACH(m, match, entries)
		    if (strcmp(line, m->value) == 0) {
			    TAILQ_REMOVE(match, m, entries);
			    break;
		    }
		if (!TAILQ_FIRST(match))
			break;
	}
	fclose(fp);
	free(line);
	if (TAILQ_FIRST(match))
		return false;
	return true;
}

static RC_STRINGLIST *
_match_list(const char *exec, const char *const *argv, const char *pidfile)
{
	RC_STRINGLIST *match = rc_stringlist_new();
	int i = 0;
	size_t l;
	char *m;

	if (exec) {
		l = strlen(exec) + 6;
		m = xmalloc(sizeof(char) * l);
		snprintf(m, l, "exec=%s", exec);
		rc_stringlist_add(match, m);
		free(m);
	}

	while (argv && argv[i]) {
		l = strlen(*argv) + strlen("argv_=") + 16;
		m = xmalloc(sizeof(char) * l);
		snprintf(m, l, "argv_0=%s", argv[i++]);
		rc_stringlist_add(match, m);
		free(m);
	}

	if (pidfile) {
		l = strlen(pidfile) + 9;
		m = xmalloc(sizeof(char) * l);
		snprintf(m, l, "pidfile=%s", pidfile);
		rc_stringlist_add(match, m);
		free(m);
	}

	return match;
}

bool
rc_service_daemon_set(const char *service, const char *exec,
    const char *const *argv,
    const char *pidfile, bool started)
{
	char dirpath[PATH_MAX];
	char file[PATH_MAX];
	int nfiles = 0;
	char oldfile[PATH_MAX] = { '\0' };
	bool retval = false;
	DIR *dp;
	struct dirent *d;
	RC_STRINGLIST *match;
	int i = 0;
	FILE *fp;

	if (!exec && !pidfile) {
		errno = EINVAL;
		return false;
	}

	snprintf(dirpath, sizeof(dirpath), RC_SVCDIR "/daemons/%s",
	    basename_c(service));

	/* Regardless, erase any existing daemon info */
	if ((dp = opendir(dirpath))) {
		match = _match_list(exec, argv, pidfile);
		while ((d = readdir(dp))) {
			if (d->d_name[0] == '.')
				continue;

			snprintf(file, sizeof(file), "%s/%s",
			    dirpath, d->d_name);
			nfiles++;

			if (!*oldfile) {
				if (_match_daemon(dirpath, d->d_name, match)) {
					unlink(file);
					strlcpy(oldfile, file, sizeof(oldfile));
					nfiles--;
				}
			} else {
				rename(file, oldfile);
				strlcpy(oldfile, file, sizeof(oldfile));
			}
		}
		closedir(dp);
		rc_stringlist_free(match);
	}

	/* Now store our daemon info */
	if (started) {
		if (mkdir(dirpath, 0755) == 0 || errno == EEXIST) {
			snprintf(file, sizeof(file), "%s/%03d",
			    dirpath, nfiles + 1);
			if ((fp = fopen(file, "w"))) {
				fprintf(fp, "exec=");
				if (exec)
					fprintf(fp, "%s", exec);
				while (argv && argv[i]) {
					fprintf(fp, "\nargv_%d=%s", i, argv[i]);
					i++;
				}
				fprintf(fp, "\npidfile=");
				if (pidfile)
					fprintf(fp, "%s", pidfile);
				fprintf(fp, "\n");
				fclose(fp);
				retval = true;
			}
		}
	} else
		retval = true;

	return retval;
}
librc_hidden_def(rc_service_daemon_set)

bool
rc_service_started_daemon(const char *service,
    const char *exec, const char *const *argv, int indx)
{
	char dirpath[PATH_MAX];
	char file[16];
	RC_STRINGLIST *match;
	bool retval = false;
	DIR *dp;
	struct dirent *d;

	if (!service || !exec)
		return false;

	snprintf(dirpath, sizeof(dirpath), RC_SVCDIR "/daemons/%s",
	    basename_c(service));
	match = _match_list(exec, argv, NULL);

	if (indx > 0) {
		snprintf(file, sizeof(file), "%03d", indx);
		retval = _match_daemon(dirpath, file, match);
	} else {
		if ((dp = opendir(dirpath))) {
			while ((d = readdir(dp))) {
				if (d->d_name[0] == '.')
					continue;
				retval = _match_daemon(dirpath, d->d_name, match);
				if (retval)
					break;
			}
			closedir(dp);
		}
	}

	rc_stringlist_free(match);
	return retval;
}
librc_hidden_def(rc_service_started_daemon)

bool
rc_service_daemons_crashed(const char *service)
{
	char dirpath[PATH_MAX];
	DIR *dp;
	struct dirent *d;
	char *path = dirpath;
	FILE *fp;
	char *line = NULL;
	size_t len = 0;
	char **argv = NULL;
	char *exec = NULL;
	char *name = NULL;
	char *pidfile = NULL;
	pid_t pid = 0;
	RC_PIDLIST *pids;
	RC_PID *p1;
	RC_PID *p2;
	char *p;
	char *token;
	bool retval = false;
	RC_STRINGLIST *list = NULL;
	RC_STRING *s;
	size_t i;

	path += snprintf(dirpath, sizeof(dirpath), RC_SVCDIR "/daemons/%s",
	    basename_c(service));

	if (!(dp = opendir(dirpath)))
		return false;

	while ((d = readdir(dp))) {
		if (d->d_name[0] == '.')
			continue;

		snprintf(path, sizeof(dirpath) - (path - dirpath), "/%s",
		    d->d_name);
		fp = fopen(dirpath, "r");
		if (!fp)
			break;

		while ((rc_getline(&line, &len, fp))) {
			p = line;
			if ((token = strsep(&p, "=")) == NULL || !p)
				continue;

			if (!*p)
				continue;

			if (strcmp(token, "exec") == 0) {
				if (exec)
					free(exec);
				exec = xstrdup(p);
			} else if (strncmp(token, "argv_", 5) == 0) {
				if (!list)
					list = rc_stringlist_new();
				rc_stringlist_add(list, p);
			} else if (strcmp(token, "name") == 0) {
				if (name)
					free(name);
				name = xstrdup(p);
			} else if (strcmp(token, "pidfile") == 0) {
				pidfile = xstrdup(p);
				break;
			}
		}
		fclose(fp);

		pid = 0;
		if (pidfile) {
			retval = true;
			if ((fp = fopen(pidfile, "r"))) {
				if (fscanf(fp, "%d", &pid) == 1)
					retval = false;
				fclose(fp);
			}
			free(pidfile);
			pidfile = NULL;

			/* We have the pid, so no need to match
			   on exec or name */
			free(exec);
			exec = NULL;
			free(name);
			name = NULL;
		} else {
			if (exec) {
				if (!list)
					list = rc_stringlist_new();
				if (!TAILQ_FIRST(list))
					rc_stringlist_add(list, exec);

				free(exec);
				exec = NULL;
			}

			if (list) {
				/* We need to flatten our linked list
				   into an array */
				i = 0;
				TAILQ_FOREACH(s, list, entries)
				    i++;
				argv = xmalloc(sizeof(char *) * (i + 1));
				i = 0;
				TAILQ_FOREACH(s, list, entries)
				    argv[i++] = s->value;
				argv[i] = '\0';
			}
		}

		if (!retval) {
			if (pid != 0) {
				if (kill(pid, 0) == -1 && errno == ESRCH)
					retval = true;
			} else if ((pids = rc_find_pids(exec,
				    (const char *const *)argv,
				    0, pid)))
			{
				p1 = LIST_FIRST(pids);
				while (p1) {
					p2 = LIST_NEXT(p1, entries);
					free(p1);
					p1 = p2;
				}
				free(pids);
			} else
				retval = true;
		}
		rc_stringlist_free(list);
		list = NULL;
		free(argv);
		argv = NULL;
		free(exec);
		exec = NULL;
		free(name);
		name = NULL;
		if (retval)
			break;
	}
	closedir(dp);
	free(line);

	return retval;
}
librc_hidden_def(rc_service_daemons_crashed)