Expand MAILTO and MAILFROM environment variables

Closes cronie-crond#26

Signed-off-by: Fernando Cappi <[email protected]>

anacron/global.h

@@ -40,6 +40,7 @@
 
 #define FAILURE_EXIT 1
 #define MAX_MSG 150
+#define MAX_EMAILSTR 255 /* max length of email address strings (254 + \0) */
 
 #include <signal.h>
 #include <time.h>
@@ -159,5 +160,6 @@ void fake_job(job_rec *jr);
 /* runjob.c */
 void tend_children();
 void launch_job(job_rec *jr);
+void expand_env_variable(const char *, char *);
 
 #endif

anacron/runjob.c

@@ -34,6 +34,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <limits.h>
+#include <wordexp.h>
 #include "global.h"
 
 #include <langinfo.h>
@@ -286,6 +287,8 @@ launch_job(job_rec *jr)
  char hostname[512];
  char *mailto;
  char *mailfrom;
+ char mailto_expanded[MAX_EMAILSTR];
+ char mailfrom_expanded[MAX_EMAILSTR];
 
  /* get hostname */
  if (gethostname(hostname, 512)) {
@@ -296,14 +299,23 @@ launch_job(job_rec *jr)
 
  /* Get the destination email address if set, or current user otherwise */
  mailto = getenv("MAILTO");
-
- if (mailto == NULL)
- mailto = username();
+ if (mailto == NULL) {
+ mailto = username();
+ }
+ else {
+ expand_env_variable(mailto, mailto_expanded);
+ mailto = mailto_expanded;
+ }
 
  /* Get the source email address if set, or current user otherwise */
  mailfrom = getenv("MAILFROM");
- if (mailfrom == NULL)
- mailfrom = username();
+ if (mailfrom == NULL) {
+ mailfrom = username();
+ }
+ else {
+ expand_env_variable(mailfrom, mailfrom_expanded);
+ mailfrom = mailfrom_expanded;
+ }
 
  /* create temporary file for stdout and stderr of the job */
  temp_file(jr); fd = jr->output_fd;
@@ -399,3 +411,20 @@ tend_children(void)
  j++;
  }
 }
+
+/* Expand env variables in 'source' arg and save to 'result'
+ */
+void expand_env_variable(const char *source, char *result) {
+ wordexp_t p;
+
+ // do not substitute commands
+ // consider unknown variable as error
+ int flags = WRDE_NOCMD | WRDE_UNDEF;
+
+ if (wordexp(source, &p, flags) == EXIT_SUCCESS) {
+ strcpy(result, p.we_wordv[0]);
+ wordfree(&p);
+ }
+ else
+ strcpy(result, source);
+}

src/do_command.c

@@ -89,6 +89,8 @@ void do_command(entry * e, user * u) {
 static int child_process(entry * e, char **jobenv) {
  int stdin_pipe[2], stdout_pipe[2];
  char *input_data, *usernm, *mailto, *mailfrom;
+ char mailto_expanded[MAX_EMAILSTR];
+ char mailfrom_expanded[MAX_EMAILSTR];
  int children = 0;
  pid_t pid = getpid();
  struct sigaction sa;
@@ -126,6 +128,16 @@ static int child_process(entry * e, char **jobenv) {
  usernm = e->pwd->pw_name;
  mailto = env_get("MAILTO", jobenv);
  mailfrom = env_get("MAILFROM", e->envp);
+
+ if (mailto != NULL) {
+ expand_env_variable(mailto, mailto_expanded);
+ mailto = mailto_expanded;
+ }
+
+ if (mailfrom != NULL) {
+ expand_env_variable(mailfrom, mailfrom_expanded);
+ mailfrom = mailfrom_expanded;
+ }
 
  /* create some pipes to talk to our future child
  */

src/env.c

@@ -28,6 +28,7 @@
 #include <string.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <wordexp.h>
 
 #include "globals.h"
 #include "funcs.h"
@@ -303,3 +304,20 @@ char **env_update_home(char **envp, const char *dir) {
 
  return envp;
 }
+
+/* Expand env variables in 'source' arg and save to 'result'
+ */
+void expand_env_variable(const char *source, char *result) {
+ wordexp_t p;
+
+ // do not substitute commands
+ // consider unknown variable as error
+ int flags = WRDE_NOCMD | WRDE_UNDEF;
+
+ if (wordexp(source, &p, flags) == EXIT_SUCCESS) {
+ strcpy(result, p.we_wordv[0]);
+ wordfree(&p);
+ }
+ else
+ strcpy(result, source);
+}

src/funcs.h

@@ -51,7 +51,8 @@ void set_cron_uid(void),
  acquire_daemonlock(int),
  log_it(const char *, PID_T, const char *, const char *, int),
  log_close(void),
- check_orphans(cron_db *);
+ check_orphans(cron_db *),
+ expand_env_variable(const char *, char *);
 #if defined WITH_INOTIFY
 void set_cron_watched(int ),
  set_cron_unwatched(int ),

src/macros.h

@@ -62,6 +62,7 @@
 #define MAX_USER_ENTRIES 1000 /* maximum crontab entries in user's crontab */
 #define MAX_GARBAGE 32768 /* max num of chars of comments and whitespaces between entries */
 #define MAX_CLOSE_FD 10000 /* max fd num to close when spawning a child process */
+#define MAX_EMAILSTR 255 /* max length of email address strings (254 + \0) */
 
  /* NOTE: these correspond to DebugFlagNames,
  * defined below.