From 4238d38f75d45793521a3b49ba421413d2b53a21 Mon Sep 17 00:00:00 2001
From: Sam Varshavchik
Date: Sun, 23 Jul 2017 23:16:48 -0400
Subject: maildrop: add the "system" command.
---
maildrop/filter.C | 63 +++++++++++++++++++++++++++++++++++++++++++-
maildrop/funcs.h | 1 +
maildrop/lexer.C | 3 +++
maildrop/maildrop.sgml | 13 +++++++--
maildrop/maildropfilter.sgml | 26 +++++++++++++++++-
maildrop/recipenode.C | 13 ++++++++-
maildrop/recipenode.h | 1 +
maildrop/recipeparse.C | 8 ++++++
maildrop/token.C | 1 +
maildrop/token.h | 1 +
10 files changed, 125 insertions(+), 5 deletions(-)
diff --git a/maildrop/filter.C b/maildrop/filter.C
index d59e2ec..abc3872 100644
--- a/maildrop/filter.C
+++ b/maildrop/filter.C
@@ -100,7 +100,7 @@ pid_t pid=fork();
{
if (write(2, p, strlen(p)) < 0 ||
write(2, "\n", 1) < 0)
- ; /* ignore */
+ ; /* ignore */
_exit(100);
}
#if NEED_NONCONST_EXCEPTIONS
@@ -273,3 +273,64 @@ int wait_stat;
return (-1);
return (0);
}
+
+void executesystem(const char *cmd)
+{
+ int devnull=open("/dev/null", O_RDONLY);
+ pid_t pid;
+
+ if (devnull < 0)
+ throw "Cannot open /dev/null";
+
+ pid=fork();
+ if (pid < 0)
+ {
+ close(devnull);
+ throw "Cannot fork.";
+ }
+
+ if (pid == 0)
+ {
+ try
+ {
+ dup2(devnull, 0);
+ close(devnull);
+ subshell(cmd);
+ }
+ catch (const char *p)
+ {
+ if (write(2, p, strlen(p)) < 0 ||
+ write(2, "\n", 1) < 0)
+ ; /* ignore */
+ _exit(100);
+ }
+#if NEED_NONCONST_EXCEPTIONS
+ catch (char *p)
+ {
+ if (write(2, p, strlen(p)) < 0 ||
+ write(2, "\n", 1) < 0)
+ ; /* ignore */
+ _exit(100);
+ }
+#endif
+ catch (...)
+ {
+ _exit(101);
+ }
+ }
+ close(devnull);
+
+int wait_stat;
+
+ while (wait(&wait_stat) != pid)
+ ;
+ wait_stat= WIFEXITED(wait_stat) ? WEXITSTATUS(wait_stat):-1;
+
+ {
+ Buffer name, val;
+
+ val.append( (unsigned long)wait_stat);
+ name="RETURNCODE";
+ SetVar(name, val);
+ }
+}
diff --git a/maildrop/funcs.h b/maildrop/funcs.h
index 3ac3a5e..ad17bac 100644
--- a/maildrop/funcs.h
+++ b/maildrop/funcs.h
@@ -20,6 +20,7 @@ extern int verbose_level;
const char *GetDefaultMailbox(const char *);
int delivery(const char *);
int filter(const char *);
+void executesystem(const char *);
void subshell(const char *);
const char *TempName(); // Return temporary filename
const char *TempName(const char *, unsigned=0); // ... with this prefix.
diff --git a/maildrop/lexer.C b/maildrop/lexer.C
index 99732dd..65e019a 100644
--- a/maildrop/lexer.C
+++ b/maildrop/lexer.C
@@ -41,6 +41,7 @@ void Lexer::token(Token &t)
case Token::tokencc:
case Token::btstring:
case Token::tokenxfilter:
+ case Token::tokensystem:
case Token::dotlock:
case Token::flock:
case Token::logfile:
@@ -346,6 +347,8 @@ missquote:
t.Type(Token::echo);
else if (pattern == "xfilter")
t.Type(Token::tokenxfilter);
+ else if (pattern == "system")
+ t.Type(Token::tokensystem);
else if (pattern == "dotlock")
t.Type(Token::dotlock);
else if (pattern == "flock")
diff --git a/maildrop/maildrop.sgml b/maildrop/maildrop.sgml
index b476d71..ca5beba 100644
--- a/maildrop/maildrop.sgml
+++ b/maildrop/maildrop.sgml
@@ -619,6 +619,13 @@ The log command is not allowed in embedded mode.
The logfile command is not allowed in embedded mode.
+
+ system
+
+
+The system command is not allowed in embedded mode.
+
+
to
@@ -663,8 +670,10 @@ suspended for any additional filter files that are included from
This allows the system administrator to have a controlled environment for
-running external commands (via the backticks, or the
-xfilter command).
+running external commands (via the backticks, the
+system
+or the
+xfilter commands).
The name of the file may not contain any periods (so that a creative
diff --git a/maildrop/maildropfilter.sgml b/maildrop/maildropfilter.sgml
index 4d91abc..c97aeec 100644
--- a/maildrop/maildropfilter.sgml
+++ b/maildrop/maildropfilter.sgml
@@ -511,7 +511,9 @@ MAILBOX="${HOME-WORD}/Mailbox"
RETURNCODEThis variable is set when maildrop
- runs the xfilter command, or a command that's
+ runs the
+ system command,
+ xfilter command, or a command that's
specified within a pair of backtick characters ( command substitution ).
The RETURNCODE variable will be set to the exit code of the
command, after it completes.
@@ -1484,6 +1486,28 @@ log expression
standard output.
+
+ system - execute a system command
+
+
+
+
+
+system expression
+
+
+
+
+
+ expression specifies an external program
+ that
+ maildrop runs as a subprocess.
+ The subprocess's standard input gets connected to
+ /dev/null, and the subprocess inherits
+ the standard output and error from
+ maildrop.
+
+
to - deliver message to a mailbox
diff --git a/maildrop/recipenode.C b/maildrop/recipenode.C
index c69c017..031eec0 100644
--- a/maildrop/recipenode.C
+++ b/maildrop/recipenode.C
@@ -496,7 +496,7 @@ RecipeNode *c;
debug += '\0';
r.errmsg(*this, debug);
}
-
+
long l=bb.Length();
if (n < 0 || n > l) n=l;
@@ -622,6 +622,17 @@ RecipeNode *c;
throw "Unable to filter message.";
b = "0";
break;
+ case system:
+ if (!firstChild)
+ throw "Internal error in system statement.";
+ firstChild->Evaluate(r,b);
+ b += '\0';
+ if (VerboseLevel() > 0)
+ merr << "maildrop: Executing system command " <<
+ (const char *)b << "\n";
+ executesystem(b);
+ b = "0";
+ break;
case exception:
if (!firstChild)
throw "Internal error in delivery statement.";
diff --git a/maildrop/recipenode.h b/maildrop/recipenode.h
index cff0a7a..4a76a42 100644
--- a/maildrop/recipenode.h
+++ b/maildrop/recipenode.h
@@ -97,6 +97,7 @@ public:
exception,
echo,
xfilter,
+ system,
dotlock,
flock,
logfile,
diff --git a/maildrop/recipeparse.C b/maildrop/recipeparse.C
index f43cc1b..6a83042 100644
--- a/maildrop/recipeparse.C
+++ b/maildrop/recipeparse.C
@@ -173,6 +173,14 @@ RecipeNode *n, *o;
throw "Syntax error.";
lex->token(cur_tok);
return (n);
+ case Token::tokensystem:
+ lex->token(cur_tok);
+ n=alloc(RecipeNode::system);
+ n->AppendSibling( ParseExpr());
+ if (cur_tok.Type() != Token::semicolon)
+ throw "Syntax error.";
+ lex->token(cur_tok);
+ return (n);
case Token::dotlock:
lex->token(cur_tok);
n=alloc(RecipeNode::dotlock);
diff --git a/maildrop/token.C b/maildrop/token.C
index c6ab42d..59ca3e0 100644
--- a/maildrop/token.C
+++ b/maildrop/token.C
@@ -50,6 +50,7 @@ static const char *names[]={
"exception",
"echo",
"xfilter",
+ "system",
"dotlock",
"flock",
"logfile",
diff --git a/maildrop/token.h b/maildrop/token.h
index 0a97471..f2829b1 100644
--- a/maildrop/token.h
+++ b/maildrop/token.h
@@ -65,6 +65,7 @@ public:
exception,
echo,
tokenxfilter,
+ tokensystem,
dotlock,
flock,
logfile,
--
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