Added state retention APIs. Implemented for check_snmp with --rate option.

See http://nagiosplugin.org/c-api-private for more details on the API.

Also updated check_snmp -l option to change the perfdata label.

1 files changed, 353 insertions, 1 deletions

diff --git a/lib/utils_base.c b/lib/utils_base.c
index 4303e159..6de92cbd 100644
--- a/lib/utils_base.c
+++ b/lib/utils_base.c
@@ -27,6 +27,56 @@
 #include "common.h"
 #include <stdarg.h>
 #include "utils_base.h"
+#include <fcntl.h>
+
+#define np_free(ptr) { if(ptr) { free(ptr); ptr = NULL; } }
+
+nagios_plugin *this_nagios_plugin=NULL;
+
+void np_init( char *plugin_name, int argc, char **argv ) {
+        if (this_nagios_plugin==NULL) {
+                this_nagios_plugin = malloc(sizeof(nagios_plugin));
+                if (this_nagios_plugin==NULL) {
+                        die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
+                            strerror(errno));
+                }
+                this_nagios_plugin->plugin_name = strdup(plugin_name);
+                if (this_nagios_plugin->plugin_name==NULL)
+                        die(STATE_UNKNOWN, _("Cannot execute strdup: %s"), strerror(errno));
+                this_nagios_plugin->argc = argc;
+                this_nagios_plugin->argv = argv;
+        }
+}
+
+void np_set_args( int argc, char **argv ) {
+        if (this_nagios_plugin==NULL)
+                die(STATE_UNKNOWN, _("This requires np_init to be called"));
+
+        this_nagios_plugin->argc = argc;
+        this_nagios_plugin->argv = argv;
+}
+
+
+void np_cleanup() {
+        if (this_nagios_plugin!=NULL) {
+                if(this_nagios_plugin->state!=NULL) {
+                        if(this_nagios_plugin->state->state_data) { 
+                                np_free(this_nagios_plugin->state->state_data->data);
+                                np_free(this_nagios_plugin->state->state_data);
+                        }
+                        np_free(this_nagios_plugin->state->name);
+                        np_free(this_nagios_plugin->state);
+                }
+                np_free(this_nagios_plugin->plugin_name);
+                np_free(this_nagios_plugin);
+        }
+        this_nagios_plugin=NULL;
+}
+
+/* Hidden function to get a pointer to this_nagios_plugin for testing */
+void _get_nagios_plugin( nagios_plugin **pointer ){
+        *pointer = this_nagios_plugin;
+}
 
 void
 die (int result, const char *fmt, ...)
@@ -35,6 +85,9 @@ die (int result, const char *fmt, ...)
         va_start (ap, fmt);
         vprintf (fmt, ap);
         va_end (ap);
+        if(this_nagios_plugin!=NULL) {
+                np_cleanup();
+        }
         exit (result);
 }
 
@@ -102,7 +155,7 @@ _set_thresholds(thresholds **my_thresholds, char *warn_string, char *critical_st
         thresholds *temp_thresholds = NULL;
 
         if ((temp_thresholds = malloc(sizeof(thresholds))) == NULL)
-                die(STATE_UNKNOWN, _("Cannot allocate memory: %s\n"),
+                die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
                     strerror(errno));
 
         temp_thresholds->warning = NULL;
@@ -310,3 +363,302 @@ char *np_extract_value(const char *varlist, const char *name, char sep) {
         return value;
 }
 
+/*
+ * Returns a string to use as a keyname, based on an md5 hash of argv, thus
+ * hopefully a unique key per service/plugin invocation. Use the extra-opts
+ * parse of argv, so that uniqueness in parameters are reflected there.
+ */
+char *_np_state_generate_key() {
+        struct sha1_ctx ctx;
+        int i;
+        char **argv = this_nagios_plugin->argv;
+        unsigned char result[20];
+        char keyname[41];
+        char *p=NULL;
+
+        sha1_init_ctx(&ctx);
+        
+        for(i=0; i<this_nagios_plugin->argc; i++) {
+                sha1_process_bytes(argv[i], strlen(argv[i]), &ctx);
+        }
+
+        sha1_finish_ctx(&ctx, &result);
+        
+        for (i=0; i<20; ++i) {
+                sprintf(&keyname[2*i], "%02x", result[i]);
+        }
+        keyname[40]='\0';
+        
+        p = strdup(keyname);
+        if(p==NULL) {
+                die(STATE_UNKNOWN, _("Cannot execute strdup: %s"), strerror(errno));
+        }
+        return p;
+}
+
+void _cleanup_state_data() {
+        if (this_nagios_plugin->state->state_data!=NULL) {
+                np_free(this_nagios_plugin->state->state_data->data);
+                np_free(this_nagios_plugin->state->state_data);
+        }
+}
+
+/*
+ * Internal function. Returns either:
+ *   envvar NAGIOS_PLUGIN_STATE_DIRECTORY
+ *   statically compiled shared state directory
+ */
+char* _np_state_calculate_location_prefix(){
+        char *env_dir;
+
+        env_dir = getenv("NAGIOS_PLUGIN_STATE_DIRECTORY");
+        if(env_dir && env_dir[0] != '\0')
+                return env_dir;
+        return NP_STATE_DIR_PREFIX;
+}
+
+/*
+ * Initiatializer for state routines.
+ * Sets variables. Generates filename. Returns np_state_key. die with
+ * UNKNOWN if exception
+ */
+void np_enable_state(char *keyname, int expected_data_version) {
+        state_key *this_state = NULL;
+        char *temp_filename = NULL;
+        char *temp_keyname = NULL;
+        char *p=NULL;
+
+        if(this_nagios_plugin==NULL)
+                die(STATE_UNKNOWN, _("This requires np_init to be called"));
+
+        this_state = (state_key *) malloc(sizeof(state_key));
+        if(this_state==NULL)
+                die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
+                    strerror(errno));
+
+        if(keyname==NULL) {
+                temp_keyname = _np_state_generate_key();
+        } else {
+                temp_keyname = strdup(keyname);
+                if(temp_keyname==NULL)
+                        die(STATE_UNKNOWN, _("Cannot execute strdup: %s"), strerror(errno));
+        }
+        /* Die if invalid characters used for keyname */
+        p = temp_keyname;
+        while(*p!='\0') {
+                if(! (isalnum(*p) || *p == '_')) {
+                        die(STATE_UNKNOWN, _("Invalid character for keyname - only alphanumerics or '_'"));
+                }
+                p++;
+        }
+        this_state->name=temp_keyname;
+        this_state->plugin_name=this_nagios_plugin->plugin_name;
+        this_state->data_version=expected_data_version;
+        this_state->state_data=NULL;
+
+        /* Calculate filename */
+        asprintf(&temp_filename, "%s/%s/%s", _np_state_calculate_location_prefix(), this_nagios_plugin->plugin_name, this_state->name);
+        this_state->_filename=temp_filename;
+
+        this_nagios_plugin->state = this_state;
+}
+
+/*
+ * Will return NULL if no data is available (first run). If key currently
+ * exists, read data. If state file format version is not expected, return
+ * as if no data. Get state data version number and compares to expected.
+ * If numerically lower, then return as no previous state. die with UNKNOWN
+ * if exceptional error.
+ */
+state_data *np_state_read() {
+        state_key *my_state_key;
+        state_data *this_state_data=NULL;
+        FILE *statefile;
+        int c;
+        int rc = FALSE;
+
+        if(this_nagios_plugin==NULL)
+                die(STATE_UNKNOWN, _("This requires np_init to be called"));
+
+        /* Open file. If this fails, no previous state found */
+        statefile = fopen( this_nagios_plugin->state->_filename, "r" );
+        if(statefile!=NULL) {
+
+                this_state_data = (state_data *) malloc(sizeof(state_data));
+                if(this_state_data==NULL)
+                        die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
+                            strerror(errno));
+
+                this_state_data->data=NULL;
+                this_nagios_plugin->state->state_data = this_state_data;
+
+                rc = _np_state_read_file(statefile);
+
+                fclose(statefile);
+        }
+
+        if(rc==FALSE) {
+                _cleanup_state_data();
+        }
+
+        return this_nagios_plugin->state->state_data;
+}
+
+/* 
+ * Read the state file
+ */
+int _np_state_read_file(FILE *f) {
+        int c, status=FALSE;
+        size_t pos;
+        char *line;
+        int i;
+        int failure=0;
+        time_t current_time, data_time;
+        enum { STATE_FILE_VERSION, STATE_DATA_VERSION, STATE_DATA_TIME, STATE_DATA_TEXT, STATE_DATA_END } expected=STATE_FILE_VERSION;
+
+        time(&current_time);
+
+        /* Note: This introduces a limit of 1024 bytes in the string data */
+        line = (char *) malloc(1024);
+        if(line==NULL)
+                die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
+                    strerror(errno));
+
+        while(!failure && (fgets(line,1024,f))!=NULL){
+                pos=strlen(line);
+                if(line[pos-1]=='\n') {
+                        line[pos-1]='\0';
+                }
+
+                if(line[0] == '#') continue;
+
+                switch(expected) {
+                        case STATE_FILE_VERSION:
+                                i=atoi(line);
+                                if(i!=NP_STATE_FORMAT_VERSION)
+                                        failure++;
+                                else
+                                        expected=STATE_DATA_VERSION;
+                                break;
+                        case STATE_DATA_VERSION:
+                                i=atoi(line);
+                                if(i != this_nagios_plugin->state->data_version)
+                                        failure++;
+                                else
+                                        expected=STATE_DATA_TIME;
+                                break;
+                        case STATE_DATA_TIME:
+                                /* If time > now, error */
+                                data_time=strtoul(line,NULL,10);
+                                if(data_time > current_time)
+                                        failure++;
+                                else {
+                                        this_nagios_plugin->state->state_data->time = data_time;
+                                        expected=STATE_DATA_TEXT;
+                                }
+                                break;
+                        case STATE_DATA_TEXT:
+                                this_nagios_plugin->state->state_data->data = strdup(line);
+                                if(this_nagios_plugin->state->state_data->data==NULL)
+                                        die(STATE_UNKNOWN, _("Cannot execute strdup: %s"), strerror(errno));
+                                expected=STATE_DATA_END;
+                                status=TRUE;
+                                break;
+                        case STATE_DATA_END:
+                                ;
+                }
+        }
+
+        np_free(line);
+        return status;
+}
+
+/*
+ * If time=NULL, use current time. Create state file, with state format 
+ * version, default text. Writes version, time, and data. Avoid locking 
+ * problems - use mv to write and then swap. Possible loss of state data if 
+ * two things writing to same key at same time. 
+ * Will die with UNKNOWN if errors
+ */
+void np_state_write_string(time_t data_time, char *data_string) {
+        FILE *fp;
+        char *temp_file=NULL;
+        int fd=0, result=0;
+        time_t current_time;
+        size_t len;
+        char *directories=NULL;
+        char *p=NULL;
+
+        if(data_time==0)
+                time(&current_time);
+        else
+                current_time=data_time;
+        
+        /* If file doesn't currently exist, create directories */
+        if(access(this_nagios_plugin->state->_filename,F_OK)!=0) {
+                asprintf(&directories, "%s", this_nagios_plugin->state->_filename);
+                if(directories==NULL)
+                        die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
+                            strerror(errno));
+
+                for(p=directories+1; *p; p++) {
+                        if(*p=='/') {
+                                *p='\0';
+                                if((access(directories,F_OK)!=0) && (mkdir(directories, S_IRWXU)!=0)) {
+                                        /* Can't free this! Otherwise error message is wrong! */
+                                        /* np_free(directories); */ 
+                                        die(STATE_UNKNOWN, _("Cannot create directory: %s"), directories);
+                                }
+                                *p='/';
+                        }
+                }
+                np_free(directories);
+        }
+
+        asprintf(&temp_file,"%s.XXXXXX",this_nagios_plugin->state->_filename);
+        if(temp_file==NULL)
+                die(STATE_UNKNOWN, _("Cannot allocate memory: %s"),
+                    strerror(errno));
+
+        if((fd=mkstemp(temp_file))==-1) {
+                np_free(temp_file);
+                die(STATE_UNKNOWN, _("Cannot create temporary filename"));
+        }
+
+        fp=(FILE *)fdopen(fd,"w");
+        if(fp==NULL) {
+                close(fd);
+                unlink(temp_file);
+                np_free(temp_file);
+                die(STATE_UNKNOWN, _("Unable to open temporary state file"));
+        }
+        
+        fprintf(fp,"# NP State file\n");
+        fprintf(fp,"%d\n",NP_STATE_FORMAT_VERSION);
+        fprintf(fp,"%d\n",this_nagios_plugin->state->data_version);
+        fprintf(fp,"%lu\n",current_time);
+        fprintf(fp,"%s\n",data_string);
+        
+        fchmod(fd, S_IRUSR | S_IWUSR | S_IRGRP);
+        
+        fflush(fp);
+
+        result=fclose(fp);
+
+        fsync(fd);
+
+        if(result!=0) {
+                unlink(temp_file);
+                np_free(temp_file);
+                die(STATE_UNKNOWN, _("Error writing temp file"));
+        }
+
+        if(rename(temp_file, this_nagios_plugin->state->_filename)!=0) {
+                unlink(temp_file);
+                np_free(temp_file);
+                die(STATE_UNKNOWN, _("Cannot rename state temp file"));
+        }
+
+        np_free(temp_file);
+}
+