Add set and reset options to control environment variables for scripts.

[ppp.git] / pppd / main.c

diff --git a/pppd/main.c b/pppd/main.c
index 014d614773d1330931f07cd19a3573f5949b11f4..1b513ca3030e1d621625ea6fedf8deb8a4ba0b2a 100644 (file)
--- a/pppd/main.c
+++ b/pppd/main.c
@@ -1615,6 +1615,52 @@ safe_fork(int infd, int outfd, int errfd)
        return 0;
 }
 
+static bool
+add_script_env(pos, newstring)
+    int pos;
+    char *newstring;
+{
+    if (pos + 1 >= s_env_nalloc) {
+       int new_n = pos + 17;
+       char **newenv = realloc(script_env, new_n * sizeof(char *));
+       if (newenv == NULL) {
+           free(newstring - 1);
+           return 0;
+       }
+       script_env = newenv;
+       s_env_nalloc = new_n;
+    }
+    script_env[pos] = newstring;
+    script_env[pos + 1] = NULL;
+    return 1;
+}
+
+static void
+remove_script_env(pos)
+    int pos;
+{
+    free(script_env[pos] - 1);
+    while ((script_env[pos] = script_env[pos + 1]) != NULL)
+       pos++;
+}
+
+/*
+ * update_system_environment - process the list of set/unset options
+ * and update the system environment.
+ */
+static void
+update_system_environment()
+{
+    struct userenv *uep;
+
+    for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
+       if (uep->ue_isset)
+           setenv(uep->ue_name, uep->ue_value, 1);
+       else
+           unsetenv(uep->ue_name);
+    }
+}
+
 /*
  * device_script - run a program to talk to the specified fds
  * (e.g. to run the connector or disconnector script).
@@ -1670,6 +1716,7 @@ device_script(program, in, out, dont_wait)
        fprintf(stderr, "pppd: setuid failed\n");
        exit(1);
     }
+    update_system_environment();
     execl("/bin/sh", "sh", "-c", program, (char *)0);
     perror("pppd: could not exec /bin/sh");
     exit(99);
@@ -1677,6 +1724,44 @@ device_script(program, in, out, dont_wait)
 }
 
 
+/*
+ * update_script_environment - process the list of set/unset options
+ * and update the script environment.  Note that we intentionally do
+ * not update the TDB.  These changes are layered on top right before
+ * exec.  It is not possible to use script_setenv() or
+ * script_unsetenv() safely after this routine is run.
+ */
+static void
+update_script_environment()
+{
+    struct userenv *uep;
+
+    for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
+       int i;
+       char *p, *newstring;
+       int nlen = strlen(uep->ue_name);
+
+       for (i = 0; (p = script_env[i]) != NULL; i++) {
+           if (strncmp(p, uep->ue_name, nlen) == 0 && p[nlen] == '=')
+               break;
+       }
+       if (uep->ue_isset) {
+           nlen += strlen(uep->ue_value) + 2;
+           newstring = malloc(nlen + 1);
+           if (newstring == NULL)
+               continue;
+           *newstring++ = 0;
+           slprintf(newstring, nlen, "%s=%s", uep->ue_name, uep->ue_value);
+           if (p != NULL)
+               script_env[i] = newstring;
+           else
+               add_script_env(i, newstring);
+       } else {
+           remove_script_env(i);
+       }
+    }
+}
+
 /*
  * run_program - execute a program with given arguments,
  * but don't wait for it unless wait is non-zero.
@@ -1747,6 +1832,7 @@ run_program(prog, args, must_exist, done, arg, wait)
 #endif
 
     /* run the program */
+    update_script_environment();
     execve(prog, args, script_env);
     if (must_exist || errno != ENOENT) {
        /* have to reopen the log, there's nowhere else
@@ -1967,25 +2053,16 @@ script_setenv(var, value, iskey)
     } else {
        /* no space allocated for script env. ptrs. yet */
        i = 0;
-       script_env = (char **) malloc(16 * sizeof(char *));
-       if (script_env == 0)
+       script_env = malloc(16 * sizeof(char *));
+       if (script_env == 0) {
+           free(newstring - 1);
            return;
+       }
        s_env_nalloc = 16;
     }
 
-    /* reallocate script_env with more space if needed */
-    if (i + 1 >= s_env_nalloc) {
-       int new_n = i + 17;
-       char **newenv = (char **) realloc((void *)script_env,
-                                         new_n * sizeof(char *));
-       if (newenv == 0)
-           return;
-       script_env = newenv;
-       s_env_nalloc = new_n;
-    }
-
-    script_env[i] = newstring;
-    script_env[i+1] = 0;
+    if (!add_script_env(i, newstring))
+       return;
 
 #ifdef USE_TDB
     if (pppdb != NULL) {
@@ -2016,9 +2093,7 @@ script_unsetenv(var)
            if (p[-1] && pppdb != NULL)
                delete_db_key(p);
 #endif
-           free(p-1);
-           while ((script_env[i] = script_env[i+1]) != 0)
-               ++i;
+           remove_script_env(i);
            break;
        }
     }