X-Git-Url: https://git.octo.it/?p=collectd.git;a=blobdiff_plain;f=src%2Fexec.c;h=a0e534c7d5fdfa03950b97ed9b9b9809b5a9ec6d;hp=36f2d4da19021eae2a63d9684058422881a9d888;hb=2d62935910e0bbb871705113aed6f19d9ae205f2;hpb=109aa67e9a982321af6547b92b5b2b6c8ae2c244

diff --git a/src/exec.c b/src/exec.c
index 36f2d4da..a0e534c7 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -28,11 +28,11 @@
 
 #include "collectd.h"
 
-#include "common.h"
 #include "plugin.h"
+#include "utils/common/common.h"
 
-#include "utils_cmd_putnotif.h"
-#include "utils_cmd_putval.h"
+#include "utils/cmds/putnotif.h"
+#include "utils/cmds/putval.h"
 
 #include <grp.h>
 #include <pwd.h>
@@ -78,9 +78,14 @@ typedef struct program_list_and_notification_s {
 } program_list_and_notification_t;
 
 /*
+ * constants
+ */
+const long int MAX_GRBUF_SIZE = 65536;
+
+/*
  * Private variables
  */
-static program_list_t *pl_head = NULL;
+static program_list_t *pl_head;
 static pthread_mutex_t pl_lock = PTHREAD_MUTEX_INITIALIZER;
 
 /*
@@ -240,11 +245,17 @@ static int exec_config(oconfig_item_t *ci) /* {{{ */
   return 0;
 } /* int exec_config }}} */
 
+#if !defined(HAVE_SETENV)
+static char env_interval[64];
+// max hostname len is 255, so this should be enough
+static char env_hostname[300];
+#endif
+
 static void set_environment(void) /* {{{ */
 {
+#ifdef HAVE_SETENV
   char buffer[1024];
 
-#ifdef HAVE_SETENV
   snprintf(buffer, sizeof(buffer), "%.3f",
            CDTIME_T_TO_DOUBLE(plugin_get_interval()));
   setenv("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
@@ -252,15 +263,29 @@ static void set_environment(void) /* {{{ */
   sstrncpy(buffer, hostname_g, sizeof(buffer));
   setenv("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
 #else
-  snprintf(buffer, sizeof(buffer), "COLLECTD_INTERVAL=%.3f",
+  snprintf(env_interval, sizeof(env_interval), "COLLECTD_INTERVAL=%.3f",
            CDTIME_T_TO_DOUBLE(plugin_get_interval()));
-  putenv(buffer);
+  putenv(env_interval);
 
-  snprintf(buffer, sizeof(buffer), "COLLECTD_HOSTNAME=%s", hostname_g);
-  putenv(buffer);
+  snprintf(env_hostname, sizeof(env_hostname), "COLLECTD_HOSTNAME=%s",
+           hostname_g);
+  putenv(env_hostname);
 #endif
 } /* }}} void set_environment */
 
+static void unset_environment(void) /* {{{ */
+{
+#ifdef HAVE_SETENV
+  unsetenv("COLLECTD_INTERVAL");
+  unsetenv("COLLECTD_HOSTNAME");
+#else
+  snprintf(env_interval, sizeof(env_interval), "COLLECTD_INTERVAL");
+  putenv(env_interval);
+  snprintf(env_hostname, sizeof(env_hostname), "COLLECTD_HOSTNAME");
+  putenv(env_hostname);
+#endif
+} /* }}} void unset_environment */
+
 __attribute__((noreturn)) static void exec_child(program_list_t *pl, int uid,
                                                  int gid, int egid) /* {{{ */
 {
@@ -340,6 +365,65 @@ static void close_pipe(int fd_pipe[2]) /* {{{ */
 } /* }}} void close_pipe */
 
 /*
+ * Get effective group ID from group name.
+ * Input arguments:
+ *       pl  :program list struct with group name
+ *       gid :group id to fallback in case egid cannot be determined.
+ * Returns:
+ *       egid effective group id if successfull,
+ *            -1 if group is not defined/not found.
+ *            -2 for any buffer allocation error.
+ */
+static int getegr_id(program_list_t *pl, int gid) /* {{{ */
+{
+  if (pl->group == NULL) {
+    return -1;
+  }
+  if (strcmp(pl->group, "") == 0) {
+    return gid;
+  }
+  struct group *gr_ptr = NULL;
+  struct group gr;
+
+  long int grbuf_size = sysconf(_SC_GETGR_R_SIZE_MAX);
+  if (grbuf_size <= 0)
+    grbuf_size = sysconf(_SC_PAGESIZE);
+  if (grbuf_size <= 0)
+    grbuf_size = 4096;
+
+  char *temp = NULL;
+  char *grbuf = NULL;
+
+  do {
+    temp = realloc(grbuf, grbuf_size);
+    if (temp == NULL) {
+      ERROR("exec plugin: getegr_id for %s: realloc buffer[%ld] failed ",
+            pl->group, grbuf_size);
+      sfree(grbuf);
+      return -2;
+    }
+    grbuf = temp;
+    if (getgrnam_r(pl->group, &gr, grbuf, grbuf_size, &gr_ptr) == 0) {
+      sfree(grbuf);
+      if (gr_ptr == NULL) {
+        ERROR("exec plugin: No such group: `%s'", pl->group);
+        return -1;
+      }
+      return gr.gr_gid;
+    } else if (errno == ERANGE) {
+      grbuf_size += grbuf_size; // increment buffer size and try again
+    } else {
+      ERROR("exec plugin: getegr_id failed %s", STRERRNO);
+      sfree(grbuf);
+      return -2;
+    }
+  } while (grbuf_size <= MAX_GRBUF_SIZE);
+  ERROR("exec plugin: getegr_id Max grbuf size reached  for %s", pl->group);
+  sfree(grbuf);
+  return -2;
+}
+
+/*
  * Creates three pipes (one for reading, one for writing and one for errors),
  * forks a child, sets up the pipes so that fd_in is connected to STDIN of
  * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
@@ -397,36 +481,12 @@ static int fork_child(program_list_t *pl, int *fd_in, int *fd_out,
 
   /* The group configured in the configfile is set as effective group, because
    * this way the forked process can (re-)gain the user's primary group. */
-  egid = -1;
-  if (pl->group != NULL) {
-    if (*pl->group != '\0') {
-      struct group *gr_ptr = NULL;
-      struct group gr;
-
-      long int grbuf_size = sysconf(_SC_GETGR_R_SIZE_MAX);
-      if (grbuf_size <= 0)
-        grbuf_size = sysconf(_SC_PAGESIZE);
-      if (grbuf_size <= 0)
-        grbuf_size = 4096;
-      char grbuf[grbuf_size];
-
-      status = getgrnam_r(pl->group, &gr, grbuf, sizeof(grbuf), &gr_ptr);
-      if (status != 0) {
-        ERROR("exec plugin: Failed to get group information "
-              "for group ``%s'': %s",
-              pl->group, STRERROR(status));
-        goto failed;
-      }
-      if (gr_ptr == NULL) {
-        ERROR("exec plugin: No such group: `%s'", pl->group);
-        goto failed;
-      }
+  egid = getegr_id(pl, gid);
+  if (egid == -2) {
+    goto failed;
+  }
 
-      egid = gr.gr_gid;
-    } else {
-      egid = gid;
-    }
-  } /* if (pl->group == NULL) */
+  set_environment();
 
   pid = fork();
   if (pid < 0) {
@@ -462,8 +522,6 @@ static int fork_child(program_list_t *pl, int *fd_in, int *fd_out,
       close(fd_pipe_err[1]);
     }
 
-    set_environment();
-
     /* Unblock all signals */
     reset_signal_mask();
 
@@ -471,6 +529,8 @@ static int fork_child(program_list_t *pl, int *fd_in, int *fd_out,
     /* does not return */
   }
 
+  unset_environment();
+
   close(fd_pipe_in[0]);
   close(fd_pipe_out[1]);
   close(fd_pipe_err[1]);
@@ -493,6 +553,8 @@ static int fork_child(program_list_t *pl, int *fd_in, int *fd_out,
   return pid;
 
 failed:
+  unset_environment();
+
   close_pipe(fd_pipe_in);
   close_pipe(fd_pipe_out);
   close_pipe(fd_pipe_err);
@@ -692,8 +754,9 @@ static void *exec_notification_one(void *arg) /* {{{ */
   else if (n->severity == NOTIF_OKAY)
     severity = "OKAY";
 
-  fprintf(fh, "Severity: %s\n"
-              "Time: %.3f\n",
+  fprintf(fh,
+          "Severity: %s\n"
+          "Time: %.3f\n",
           severity, CDTIME_T_TO_DOUBLE(n->time));
 
   /* Print the optional fields */
@@ -856,6 +919,11 @@ static int exec_shutdown(void) /* {{{ */
       INFO("exec plugin: Sent SIGTERM to %hu", (unsigned short int)pl->pid);
     }
 
+    for (int i = 0; pl->argv[i] != NULL; i++) {
+      sfree(pl->argv[i]);
+    }
+    sfree(pl->argv);
+    sfree(pl->exec);
     sfree(pl->user);
     sfree(pl);