* Don't strip binaries for debian package if built with

  DEB_BUILD_OPTIONS=nostrip. Closes: #437577
* Include Michael Tokarev's lckdo program and replace / conflict with the
  current lckdo package. (Robert Edmonds) Closes: #432906
* lckdo: Don't clear other flags when setting close on exec.

1 files changed, 227 insertions, 0 deletions

diff --git a/lckdo.c b/lckdo.c
new file mode 100644
index 0000000..39b7f17
--- /dev/null
+++ b/lckdo.c
@@ -0,0 +1,227 @@
+/* lckdo.c: run a program with a lock held,
+ * to prevent multiple processes running in parallel.
+ * Use just like `nice' or `nohup'.
+ * Written by Michael Tokarev <mjt@tls.msk.ru>
+ * Public domain.
+ */
+
+#define _GNU_SOURCE
+#define _BSD_SOURCE
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <sysexits.h>
+#include <sys/file.h>
+#include <sys/wait.h>
+#include <signal.h>
+
+/* compile with -DUSE_FLOCK to use flock() instead of fcntl() */
+
+#if !defined(USE_FLOCK) && !defined(F_SETLKW)
+# define USE_FLOCK
+#endif
+
+#ifndef __GNUC__
+# ifndef __attribute__
+#   define __attribute__(x)
+# endif
+#endif
+
+static char *progname;
+static void
+__attribute__((format(printf,3,4)))
+__attribute__((noreturn))
+error(int errnum, int exitcode, const char *fmt, ...) {
+  va_list ap;
+  fprintf(stderr, "%s: ", progname);
+  va_start(ap, fmt); vfprintf(stderr, fmt, ap); va_end(ap);
+  if (errnum) fprintf(stderr, ": %s\n", strerror(errnum));
+  else fputs("\n", stderr);
+  exit(exitcode);
+}
+
+static const char *lckfile;
+static int quiet;
+
+static void sigalarm(int sig) {
+  if (quiet)
+    _exit(EX_TEMPFAIL);
+  error(0, EX_TEMPFAIL,
+        "lock file `%s' is already locked (timeout waiting)", lckfile);
+  sig = sig;
+}
+
+int main(int argc, char **argv) {
+  int fd;
+  int c;
+  int create = O_CREAT;
+  int dofork = 1;
+  int waittime = 0;
+  int shared = 0;
+  int test = 0;
+  int fdn = -1;
+#ifndef USE_FLOCK
+  struct flock fl;
+#endif
+
+  if ((progname = strrchr(argv[0], '/')) == NULL) progname = argv[0];
+  else argv[0] = ++progname;
+
+  if (argc == 1) {
+    printf(
+"%s: execute a program with a lock set.\n"
+"Usage: %s [options] lockfile program [arguments]\n"
+"where options are:\n"
+" -w - if the lock is already held by another process,\n"
+"   wait for it to complete instead of failing immediately\n"
+" -W sec - the same as -w but wait not more than sec seconds\n"
+" -e - execute the program directly, no fork/wait\n"
+"   (keeps extra open file descriptor)\n"
+" -E nnn - set the fd# to keep open in -e case (implies -e)\n"
+" -n - do not create the lock file if it does not exist\n"
+" -q - produce no output if lock is already held\n"
+" -s - lock in shared (read) mode\n"
+" -x - lock in exclusive (write) mode (default)\n"
+" -t - test for lock existence"
+#ifndef USE_FLOCK
+                              " (just prints pid if any with -q)\n"
+#endif
+"   (implies -n)\n"
+            , progname, progname);
+    return 0;
+  }
+
+  while((c = getopt(argc, argv, "+wW:neE:sxtq")) != EOF)
+    switch(c) {
+      case 'w':
+        if (!waittime)
+          waittime = -1;
+        break;
+      case 'W':
+        if ((waittime = atoi(optarg)) < 1)
+          error(0, EX_USAGE, "invalid wait time `%s'", optarg);
+        break;
+      case 't':
+        test = 1;
+        /* fall */
+      case 'n':
+        create = 0;
+        break;
+      case 'E':
+        if ((fdn = atoi(optarg)) < 0 || fdn == 2)
+          error(0, EX_USAGE, "invalid fd# `%s'", optarg);
+        /* fall */
+      case 'e':
+        dofork = 0;
+        break;
+      case 's':
+        shared = 1;
+        break;
+      case 'x':
+        shared = 0;
+        break;
+      case 'q':
+        quiet = 1;
+        break;
+      default:
+        return EX_USAGE;
+    }
+
+  argc -= optind; argv += optind;
+  if (!argc || (!test && argc < 2))
+    error(0, EX_USAGE, "too few arguments given");
+
+  lckfile = *argv++;
+
+#ifdef USE_FLOCK
+  create |= O_RDONLY;
+#else
+  if (!test)
+    create |= shared ? O_RDONLY : O_WRONLY;
+#endif
+  fd = open(lckfile, create, 0666);
+  if (fd < 0) {
+    if (test && errno == ENOENT) {
+      if (!quiet)
+        printf("lockfile `%s' is not locked\n", lckfile);
+      return 0;
+    }
+    error(errno, EX_CANTCREAT, "unable to open `%s'", lckfile);
+  }
+
+  if (!test && fdn >= 0) {
+    /* dup it early to comply with stupid POSIX fcntl locking semantics */
+    if (dup2(fd, fdn) < 0)
+      error(errno, EX_OSERR, "dup2(%d,%d) failed", fd, fdn);
+    close(fd);
+    fd = fdn;
+  }
+
+  if (test)
+    waittime = 0;
+  else if (waittime > 0) {
+    alarm(waittime);
+    signal(SIGALRM, sigalarm);
+  }
+#ifdef USE_FLOCK
+  c = flock(fd, (shared ? LOCK_SH : LOCK_EX) | (waittime ? 0 : LOCK_NB));
+  if (test && c < 0 &&
+      (errno == EWOULDBLOCK || errno == EAGAIN || errno == EACCES)) {
+    if (!quiet)
+      printf("lockfile `%s' is locked\n", lckfile);
+    else
+      printf("locked\n");
+    return EX_TEMPFAIL;
+  }
+#else
+  memset(&fl, 0, sizeof(fl));
+  fl.l_type = shared ? F_RDLCK : F_WRLCK;
+  c = fcntl(fd, test ? F_GETLK : waittime ? F_SETLKW : F_SETLK, &fl);
+  if (test && c == 0) {
+    if (fl.l_type == F_UNLCK) {
+      if (!quiet)
+        printf("lockfile `%s' is not locked\n", lckfile);
+      return 0;
+    }
+    if (!quiet)
+      printf("lockfile `%s' is locked by process %d\n", lckfile, fl.l_pid);
+    else
+      printf("%d\n", fl.l_pid);
+    return EX_TEMPFAIL;
+  }
+#endif
+  if (waittime > 0)
+    alarm(0);
+  if (c < 0) {
+    if (errno != EWOULDBLOCK && errno != EAGAIN && errno != EACCES)
+      error(errno, EX_OSERR, "unable to lock `%s'", lckfile);
+    else if (quiet)
+      return EX_TEMPFAIL;
+    else
+      error(0, EX_TEMPFAIL, "lockfile `%s' is already locked", lckfile);
+  }
+
+  if (dofork) {
+    pid_t pid;
+    int flags = fcntl(fd, F_GETFD, 0);
+    if (flags < 0)
+      error(errno, EX_OSERR, "fcntl() failed");
+    fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+    pid = fork();
+    if (pid < 0)
+      error(errno, EX_OSERR, "unable to fork");
+    else if (pid) {
+      if (wait(&c) < 0)
+        error(errno, EX_OSERR, "wait() failed");
+      if (WIFSIGNALED(c))
+        error(0, EX_SOFTWARE, "%s: %s", *argv, strsignal(WTERMSIG(c)));
+      return WEXITSTATUS(c);
+    }
+  }
+  execvp(*argv, argv);
+  error(errno, EX_OSERR, "unable to execute %s", *argv);
+}