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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 12:06:34 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 12:06:34 +0000
commit5e61585d76ae77fd5e9e96ebabb57afa4d74880d (patch)
tree2b467823aaeebc7ef8bc9e3cabe8074eaef1666d /src/util/exec_command.c
parentInitial commit. (diff)
downloadpostfix-upstream/3.5.24.tar.xz
postfix-upstream/3.5.24.zip
Adding upstream version 3.5.24.upstream/3.5.24upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/exec_command.c')
-rw-r--r--src/util/exec_command.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/src/util/exec_command.c b/src/util/exec_command.c
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+/*++
+/* NAME
+/* exec_command 3
+/* SUMMARY
+/* execute command
+/* SYNOPSIS
+/* #include <exec_command.h>
+/*
+/* NORETURN exec_command(command)
+/* const char *command;
+/* DESCRIPTION
+/* \fIexec_command\fR() replaces the current process by an instance
+/* of \fIcommand\fR. This routine uses a simple heuristic to avoid
+/* the overhead of running a command shell interpreter.
+/* DIAGNOSTICS
+/* This routine never returns. All errors are fatal.
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <unistd.h>
+#include <string.h>
+#ifdef USE_PATHS_H
+#include <paths.h>
+#endif
+#include <errno.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <argv.h>
+#include <exec_command.h>
+
+/* Application-specific. */
+
+#define SPACE_TAB " \t"
+
+/* exec_command - exec command */
+
+NORETURN exec_command(const char *command)
+{
+ ARGV *argv;
+
+ /*
+ * Character filter. In this particular case, we allow space and tab in
+ * addition to the regular character set.
+ */
+ static char ok_chars[] = "1234567890!@%-_=+:,./\
+abcdefghijklmnopqrstuvwxyz\
+ABCDEFGHIJKLMNOPQRSTUVWXYZ" SPACE_TAB;
+
+ /*
+ * See if this command contains any shell magic characters.
+ */
+ if (command[strspn(command, ok_chars)] == 0
+ && command[strspn(command, SPACE_TAB)] != 0) {
+
+ /*
+ * No shell meta characters found, so we can try to avoid the overhead
+ * of running a shell. Just split the command on whitespace and exec
+ * the result directly.
+ */
+ argv = argv_split(command, SPACE_TAB);
+ (void) execvp(argv->argv[0], argv->argv);
+
+ /*
+ * Auch. Perhaps they're using some shell built-in command.
+ */
+ if (errno != ENOENT || strchr(argv->argv[0], '/') != 0)
+ msg_fatal("execvp %s: %m", argv->argv[0]);
+
+ /*
+ * Not really necessary, but...
+ */
+ argv_free(argv);
+ }
+
+ /*
+ * Pass the command to a shell.
+ */
+ (void) execl(_PATH_BSHELL, "sh", "-c", command, (char *) 0);
+ msg_fatal("execl %s: %m", _PATH_BSHELL);
+}
+
+#ifdef TEST
+
+ /*
+ * Yet another proof-of-concept test program.
+ */
+#include <vstream.h>
+#include <msg_vstream.h>
+
+int main(int argc, char **argv)
+{
+ msg_vstream_init(argv[0], VSTREAM_ERR);
+ if (argc != 2)
+ msg_fatal("usage: %s 'command'", argv[0]);
+ exec_command(argv[1]);
+}
+
+#endif