crond: add handling of "MAILTO=user" lines

sendmail: handle a case when the whole mail comes from stdin
(and no separate sender/subj is provided)
both by dronnikov AT gmail.com

function                                             old     new   delta
sendgetmail_main                                    1509    1674    +165
SynchronizeFile                                      671     767     +96
packed_usage                                       24054   24088     +34
crond_main                                          1404    1420     +16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 311/0)             Total: 311 bytes

2 files changed, 67 insertions, 20 deletions

diff --git a/miscutils/crond.c b/miscutils/crond.c
index ba9cf3581..98dd22d9d 100644
--- a/miscutils/crond.c
+++ b/miscutils/crond.c
@@ -33,7 +33,11 @@
 #define SENDMAIL        "sendmail"
 #endif
 #ifndef SENDMAIL_ARGS
-#define SENDMAIL_ARGS   "-ti", "oem"
+#       if ENABLE_SENDMAIL
+#               define SENDMAIL_ARGS   "localhost", line->cl_MailTo
+#       else
+#               define SENDMAIL_ARGS   "-ti", "oem"
+#       endif
 #endif
 #ifndef CRONUPDATE
 #define CRONUPDATE      "cron.update"
@@ -59,6 +63,7 @@ typedef struct CronLine {
 #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
         int cl_MailPos;         /* 'empty file' size                    */
         smallint cl_MailFlag;   /* running pid is for mail              */
+        char *cl_MailTo;        /* whom to mail results                 */
 #endif
         /* ordered by size, not in natural order. makes code smaller: */
         char cl_Dow[7];         /* 0-6, beginning sunday                */
@@ -449,6 +454,9 @@ static void SynchronizeFile(const char *fileName)
         int maxEntries;
         int maxLines;
         char buf[1024];
+#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+        char *mailTo = NULL;
+#endif
 
         if (!fileName)
                 return;
@@ -485,6 +493,14 @@ static void SynchronizeFile(const char *fileName)
                         if (DebugOpt) {
                                 crondlog(LVL5 "user:%s entry:%s", fileName, buf);
                         }
+                        /* check if line is setting MAILTO= */
+                        if (0 == strncmp("MAILTO=", buf, 7)) {
+#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+                                free(mailTo);
+                                mailTo = (buf[7]) ? xstrdup(buf+7) : NULL;
+#endif /* otherwise just ignore such lines */
+                                continue;
+                        }
                         *pline = line = xzalloc(sizeof(CronLine));
                         /* parse date ranges */
                         ptr = ParseField(file->cf_User, line->cl_Mins, 60, 0, NULL, buf);
@@ -498,10 +514,14 @@ static void SynchronizeFile(const char *fileName)
                                 continue;
                         }
                         /*
-                         * fix days and dow - if one is not * and the other
-                         * is *, the other is set to 0, and vise-versa
+                         * fix days and dow - if one is not "*" and the other
+                         * is "*", the other is set to 0, and vise-versa
                          */
                         FixDayDow(line);
+#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
+                        /* copy mailto (can be NULL) */
+                        line->cl_MailTo = xstrdup(mailTo);
+#endif
                         /* copy command */
                         line->cl_Shell = xstrdup(ptr);
                         if (DebugOpt) {
@@ -515,7 +535,7 @@ static void SynchronizeFile(const char *fileName)
                 FileBase = file;
 
                 if (maxLines == 0 || maxEntries == 0) {
-                        crondlog(WARN9 "maximum number of lines reached for user %s", fileName);
+                        crondlog(WARN9 "user %s: too many lines", fileName);
                 }
         }
         fclose(fi);
@@ -567,7 +587,7 @@ static void SynchronizeDir(void)
 
                 if (!dir)
                         crondlog(DIE9 "can't chdir(%s)", "."); /* exits */
-                while ((den = readdir(dir))) {
+                while ((den = readdir(dir)) != NULL) {
                         if (strchr(den->d_name, '.') != NULL) {
                                 continue;
                         }
@@ -811,23 +831,25 @@ ForkJob(const char *user, CronLine *line, int mailFd,
 static void RunJob(const char *user, CronLine *line)
 {
         char mailFile[128];
-        int mailFd;
+        int mailFd = -1;
 
         line->cl_Pid = 0;
         line->cl_MailFlag = 0;
 
-        /* open mail file - owner root so nobody can screw with it. */
-        snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, getpid());
-        mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
+        if (line->cl_MailTo) {
+                /* open mail file - owner root so nobody can screw with it. */
+                snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, getpid());
+                mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
 
-        if (mailFd >= 0) {
-                line->cl_MailFlag = 1;
-                fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", user,
-                        line->cl_Shell);
-                line->cl_MailPos = lseek(mailFd, 0, SEEK_CUR);
-        } else {
-                crondlog(ERR20 "cannot create mail file %s for user %s, "
-                                "discarding output", mailFile, user);
+                if (mailFd >= 0) {
+                        line->cl_MailFlag = 1;
+                        fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", user,
+                                line->cl_Shell);
+                        line->cl_MailPos = lseek(mailFd, 0, SEEK_CUR);
+                } else {
+                        crondlog(ERR20 "cannot create mail file %s for user %s, "
+                                        "discarding output", mailFile, user);
+                }
         }
 
         ForkJob(user, line, mailFd, DEFAULT_SHELL, "-c", line->cl_Shell, mailFile);
@@ -877,7 +899,8 @@ static void EndJob(const char *user, CronLine *line)
                 close(mailFd);
                 return;
         }
-        ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL);
+        if (line->cl_MailTo)
+                ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL);
 }
 
 #else /* crond without sendmail */
diff --git a/networking/sendmail.c b/networking/sendmail.c
index 973d712b9..242bb0eaf 100644
--- a/networking/sendmail.c
+++ b/networking/sendmail.c
@@ -273,6 +273,7 @@ int sendgetmail_main(int argc ATTRIBUTE_UNUSED, char **argv)
 
                 OPTS_c = 1 << 6,        // sendmail: assumed charset
                 OPTS_t = 1 << 7,        // sendmail: recipient(s)
+                OPTS_i = 1 << 8,        // sendmail: ignore lone dots in message body (implied)
         };
 
         const char *options;
@@ -288,8 +289,8 @@ int sendgetmail_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 // SENDMAIL
                 // save initial stdin (body or attachements can be piped!)
                 xdup2(STDIN_FILENO, INITIAL_STDIN_FILENO);
-                opt_complementary = "-2:w+:t:t::"; // count(-t) > 0
-                options = "w:U:P:X" "ns:c:t:";
+                opt_complementary = "-2:w+:t::";
+                options = "w:U:P:X" "ns:c:t:i";
         } else {
                 // FETCHMAIL
                 opt_after_connect = NULL;
@@ -346,6 +347,29 @@ int sendgetmail_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 // get the sender
                 opt_from = sane(*argv++);
 
+                // if no recipients _and_ no body files specified -> enter all-included mode
+                // i.e. scan stdin for To: and Subject: lines ...
+                // ... and then use the rest of stdin as message body
+                if (!opt_recipients && !*argv) {
+                        // fetch recipients and (optionally) subject
+                        char *s;
+                        while ((s = xmalloc_reads(INITIAL_STDIN_FILENO, NULL, NULL)) != NULL) {
+                                if (0 == strncmp("To: ", s, 4)) {
+                                        llist_add_to_end(&opt_recipients, s+4);
+                                } else if (0 == strncmp("Subject: ", s, 9)) {
+                                        opt_subject = s+9;
+                                        opts |= OPTS_s;
+                                } else {
+                                        char first = s[0];
+                                        free(s);
+                                        if (!first)
+                                                break; // empty line
+                                }
+                        }
+                        // order to read body from stdin
+                        *--argv = (char *)"-";
+                }
+
                 // introduce to server
                 // we should start with modern EHLO
                 if (250 != smtp_checkp("EHLO %s", opt_from, -1)) {