crond: code shrink

function                                             old     new   delta
crond_main                                          1431    1472     +41
fork_job                                             457     389     -68

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 31 insertions, 36 deletions

diff --git a/miscutils/crond.c b/miscutils/crond.c
index 28722563c..a459c6a8c 100644
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -29,7 +29,7 @@
 # define SENDMAIL       "sendmail"
 #endif
 #ifndef SENDMAIL_ARGS
-# define SENDMAIL_ARGS  "-ti", NULL
+# define SENDMAIL_ARGS  "-ti"
 #endif
 #ifndef CRONUPDATE
 # define CRONUPDATE     "cron.update"
@@ -53,9 +53,8 @@ typedef struct CronLine {
         char *cl_cmd;                   /* shell command */
         pid_t cl_pid;                   /* >0:running, <0:needs to be started in this minute, 0:dormant */
 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
-        int cl_empty_mail_size;         /* size of mail header only */
+        int cl_empty_mail_size;         /* size of mail header only, 0 if no mailfile */
         char *cl_mailto;                /* whom to mail results, may be NULL */
-        smallint cl_mail_result;        /* mail file is created, need to send it on completion */
 #endif
         /* ordered by size, not in natural order. makes code smaller: */
         char cl_Dow[7];                 /* 0-6, beginning sunday */
@@ -536,13 +535,11 @@ static void change_user(struct passwd *pas)
 // TODO: sendmail should be _run-time_ option, not compile-time!
 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
 
-//TODO: return pid (and stop passing line);
-// stop passing mail_filename here but process it in caller
-static void
-fork_job(const char *user, CronLine *line, int mailFd,
-                const char *prog, const char *cmd, const char *arg,
-                const char *mail_filename)
-{
+static pid_t
+fork_job(const char *user, int mailFd,
+                const char *prog,
+                const char *shell_cmd /* if NULL, we run sendmail */
+) {
         struct passwd *pas;
         pid_t pid;
 
@@ -563,37 +560,25 @@ fork_job(const char *user, CronLine *line, int mailFd,
                         crondlog(LVL5 "child running %s", prog);
                 }
                 if (mailFd >= 0) {
-                        xmove_fd(mailFd, mail_filename ? 1 : 0);
+                        xmove_fd(mailFd, shell_cmd ? 1 : 0);
                         dup2(1, 2);
                 }
                 /* crond 3.0pl1-100 puts tasks in separate process groups */
                 bb_setpgrp();
-                execlp(prog, prog, cmd, arg, (char *) NULL);
-                crondlog(ERR20 "can't exec, user %s cmd %s %s %s", user, prog, cmd, arg);
-                if (mail_filename) {
-                        fdprintf(1, "Exec failed: %s -c %s\n", prog, arg);
+                execlp(prog, prog, (shell_cmd ? "-c" : SENDMAIL_ARGS), shell_cmd, (char *) NULL);
+                crondlog(ERR20 "can't execute '%s' for user %s", prog, user);
+                if (shell_cmd) {
+                        fdprintf(1, "Exec failed: %s -c %s\n", prog, shell_cmd);
                 }
                 _exit(EXIT_SUCCESS);
         }
 
-        line->cl_pid = pid;
         if (pid < 0) {
                 /* FORK FAILED */
                 crondlog(ERR20 "can't vfork");
  err:
-                line->cl_pid = 0;
-                if (mail_filename) {
-                        unlink(mail_filename);
-                }
-        } else {
-                /* PARENT, FORK SUCCESS */
-                if (mail_filename) {
-                        /* rename mail-file based on pid of process */
-                        char *mailFile2 = xasprintf("%s/cron.%s.%d", TMPDIR, user, (int)pid);
-                        rename(mail_filename, mailFile2); // TODO: xrename?
-                        free(mailFile2);
-                }
-        }
+                pid = 0;
+        } /* else: PARENT, FORK SUCCESS */
 
         /*
          * Close the mail file descriptor.. we can't just leave it open in
@@ -602,6 +587,7 @@ fork_job(const char *user, CronLine *line, int mailFd,
         if (mailFd >= 0) {
                 close(mailFd);
         }
+        return pid;
 }
 
 static void start_one_job(const char *user, CronLine *line)
@@ -610,7 +596,7 @@ static void start_one_job(const char *user, CronLine *line)
         int mailFd = -1;
 
         line->cl_pid = 0;
-        line->cl_mail_result = 0;
+        line->cl_empty_mail_size = 0;
 
         if (line->cl_mailto) {
                 /* Open mail file (owner is root so nobody can screw with it) */
@@ -618,7 +604,6 @@ static void start_one_job(const char *user, CronLine *line)
                 mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
 
                 if (mailFd >= 0) {
-                        line->cl_mail_result = 1;
                         fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_mailto,
                                 line->cl_cmd);
                         line->cl_empty_mail_size = lseek(mailFd, 0, SEEK_CUR);
@@ -628,7 +613,17 @@ static void start_one_job(const char *user, CronLine *line)
                 }
         }
 
-        fork_job(user, line, mailFd, DEFAULT_SHELL, "-c", line->cl_cmd, mailFile);
+        line->cl_pid = fork_job(user, mailFd, DEFAULT_SHELL, line->cl_cmd);
+        if (mailFd >= 0) {
+                if (line->cl_pid <= 0) {
+                        unlink(mailFile);
+                } else {
+                        /* rename mail-file based on pid of process */
+                        char *mailFile2 = xasprintf("%s/cron.%s.%d", TMPDIR, user, (int)line->cl_pid);
+                        rename(mailFile, mailFile2); // TODO: xrename?
+                        free(mailFile2);
+                }
+        }
 }
 
 /*
@@ -647,11 +642,10 @@ static void process_finished_job(const char *user, CronLine *line)
                 /* No job */
                 return;
         }
-        if (line->cl_mail_result == 0) {
+        if (line->cl_empty_mail_size <= 0) {
                 /* End of job and no mail file, or end of sendmail job */
                 return;
         }
-        line->cl_mail_result = 0;
 
         /*
          * End of primary job - check for mail file.
@@ -673,8 +667,9 @@ static void process_finished_job(const char *user, CronLine *line)
                 close(mailFd);
                 return;
         }
-        /* if (line->cl_mailto) - always true if cl_mail_result was true */
-                fork_job(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL);
+        line->cl_empty_mail_size = 0;
+        /* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */
+                line->cl_pid = fork_job(user, mailFd, SENDMAIL, NULL);
 }
 
 #else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */