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SNMP Frontend, fix handling of snmpd down and memory leaks

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If snmpd is down, clixon_snmp does not start
If snmpd stops, clixon_snmp quits
Mem leaks fixed
This commit is contained in:
Olof hagsand 2022-06-05 15:30:55 +02:00
parent eb6185c888
commit 6e1c20e873
7 changed files with 269 additions and 108 deletions
Download patch file Download diff file Expand all files Collapse all files

2
apps/snmp/snmp_handler.c
View file

@ -340,6 +340,8 @@ snmp_scalar_set(clicon_handle h,
ok:
retval = 0;
done:
if (api_path)
free(api_path);
if (cb)
cbuf_free(cb);
if (xtop)

126
apps/snmp/snmp_lib.c
View file

@ -139,15 +139,51 @@ snmp_msg_int2str(int msg)
return clicon_int2str(snmp_msg_map, msg);
}
/*! Free clixon snmp handler struct
/*! Duplicate clixon snmp handler struct
* Use signature of libnetsnmp data_clone field of netsnmp_mib_handler in agent_handler.h
* @param[in] arg
*/
int
snmp_handle_free(clixon_snmp_handle *sh)
void*
snmp_handle_clone(void *arg)
{
if (sh->sh_cvk)
cvec_free(sh->sh_cvk);
free(sh);
return 0;
clixon_snmp_handle *sh0 = (clixon_snmp_handle *)arg;
clixon_snmp_handle *sh1 = NULL;
if (sh0 == NULL)
return NULL;
if ((sh1 = malloc(sizeof(*sh1))) == NULL){
clicon_err(OE_UNIX, errno, "malloc");
return NULL;
}
memset(sh1, 0, sizeof(*sh1));
if (sh0->sh_cvk &&
(sh1->sh_cvk = cvec_dup(sh0->sh_cvk)) == NULL){
clicon_err(OE_UNIX, errno, "cvec_dup");
return NULL;
}
return (void*)sh1;
}
/*! Free clixon snmp handler struct
* Use signature of libnetsnmp data_free field of netsnmp_mib_handler in agent_handler.h
* @param[in] arg
*/
void
snmp_handle_free(void *arg)
{
clixon_snmp_handle *sh = (clixon_snmp_handle *)arg;
if (sh != NULL){
if (sh->sh_cvk)
cvec_free(sh->sh_cvk);
if (sh->sh_table_info){
if (sh->sh_table_info->indexes){
snmp_free_varbind(sh->sh_table_info->indexes);
}
free(sh->sh_table_info);
}
free(sh);
}
}
/*! Translate from YANG to SNMP asn1.1 type ids (not value)
@ -167,9 +203,9 @@ type_yang2asn1(yang_stmt *ys,
int extended)
{
int retval = -1;
yang_stmt *yrestype; /* resolved type */
char *restype; /* resolved type */
char *origtype=NULL; /* original type */
yang_stmt *yrestype; /* resolved type */
char *restype; /* resolved type */
char *origtype = NULL; /* original type */
int at;
yang_stmt *ypath;
yang_stmt *yref;
@ -186,6 +222,10 @@ type_yang2asn1(yang_stmt *ys,
}
if (yang_path_arg(ys, yang_argument_get(ypath), &yref) < 0)
goto done;
if (origtype){
free(origtype);
origtype = NULL;
}
if (yang_type_get(yref, &origtype, &yrestype, NULL, NULL, NULL, NULL, NULL) < 0)
goto done;
restype = yrestype?yang_argument_get(yrestype):NULL;
@ -226,6 +266,8 @@ type_yang2asn1(yang_stmt *ys,
*asn1_type = at;
retval = 0;
done:
if (origtype)
free(origtype);
return retval;
}
@ -251,10 +293,10 @@ type_snmp2xml(yang_stmt *ys,
int retval = -1;
char *cvstr;
enum cv_type cvtype;
cg_var *cv;
yang_stmt *yrestype; /* resolved type */
char *restype; /* resolved type */
char *origtype=NULL; /* original type */
cg_var *cv = NULL;
yang_stmt *yrestype; /* resolved type */
char *restype; /* resolved type */
char *origtype = NULL; /* original type */
clicon_debug(1, "%s", __FUNCTION__);
if (valstr == NULL){
@ -326,14 +368,17 @@ type_snmp2xml(yang_stmt *ys,
goto fail;
break;
}
if ((*valstr = cv2str_dup(cv)) == NULL){
clicon_err(OE_UNIX, errno, "cv2str_dup");
goto done;
}
retval = 1;
done:
clicon_debug(1, "%s %d", __FUNCTION__, retval);
clicon_debug(2, "%s %d", __FUNCTION__, retval);
if (cv)
cv_free(cv);
if (origtype)
free(origtype);
return retval;
fail:
retval = 0;
@ -359,9 +404,9 @@ type_xml2snmp_pre(char *xmlstr0,
{
int retval = -1;
yang_stmt *yrestype; /* resolved type */
char *restype; /* resolved type */
char *origtype=NULL; /* original type */
yang_stmt *yrestype; /* resolved type */
char *restype; /* resolved type */
char *origtype = NULL; /* original type */
char *str = NULL;
int ret;
@ -402,6 +447,8 @@ type_xml2snmp_pre(char *xmlstr0,
retval = 1;
done:
clicon_debug(2, "%s %d", __FUNCTION__, retval);
if (origtype)
free(origtype);
return retval;
fail:
retval = 0;
@ -603,11 +650,11 @@ yang2xpath_cb(yang_stmt *ys,
/*! Construct an xpath from yang statement
* Recursively construct it to the top.
* @param[in] ys Yang statement
* @param[in] keyvec Array of [name,val]s as a cvec of key name and values
* @param[out] xpath Malloced xpath string, use free() after use
* @retval 0 OK
* @retval -1 Error
* @param[in] ys Yang statement
* @param[in] keyvec Array of [name,val]s as a cvec of key name and values
* @param[out] xpath Malloced xpath string, use free() after use
* @retval 0 OK
* @retval -1 Error
* @note
* 1. This should really be in a core .c file, like clixon_yang, BUT
* 2. It is far from complete so maybe keep it here as a special case
@ -693,3 +740,34 @@ snmp_body2oid(cxobj *xi,
cbuf_free(enc);
return retval;
}
/*========== libnetsnmp-specific code ===============
* Peeks into internal lib global variables, may be sensitive to library change
*/
/*! Check if netsnmp is connected
* @retval 1 yes, running
* @retval 0 No, not running
* XXX: this peeks into the "main_session" global variable in agent/snmp_agent.c
* Tried to find API function but failed
*/
int
snmp_agent_check(void)
{
extern netsnmp_session *main_session;
return (main_session != NULL) ? 1 : 0;
}
/*! Cleanup remaining libnetsnmb memory
* XXX: this peeks into the "tclist" global variable in snmplib/parse.c
* Tried to find API function but failed
*/
int
snmp_agent_cleanup(void)
{
extern void *tclist;
if (tclist)
free(tclist);
return 0;
}

6
apps/snmp/snmp_lib.h
View file

@ -52,6 +52,7 @@ struct clixon_snmp_handle {
size_t sh_oidlen;
char *sh_default; /* MIB default value leaf only */
cvec *sh_cvk; /* Index/Key variables */
netsnmp_table_registration_info *sh_table_info; /* To mimic table-handler in libnetsnmp code*/
};
typedef struct clixon_snmp_handle clixon_snmp_handle;
@ -60,7 +61,8 @@ typedef struct clixon_snmp_handle clixon_snmp_handle;
*/
int snmp_access_str2int(char *modes_str);
const char *snmp_msg_int2str(int msg);
int snmp_handle_free(clixon_snmp_handle *sh);
void *snmp_handle_clone(void *arg);
void snmp_handle_free(void *arg);
int type_yang2asn1(yang_stmt *ys, int *asn1_type, int extended);
int type_snmp2xml(yang_stmt *ys,
netsnmp_variable_list *requestvb,
@ -71,6 +73,8 @@ int type_xml2snmp_pre(char *xmlstr, yang_stmt *ys, char **snmpstr);
int type_xml2snmp(char *snmpstr, int *asn1type, u_char **snmpval, size_t *snmplen, char **reason);
int yang2xpath(yang_stmt *ys, cvec *keyvec, char **xpath);
int snmp_body2oid(cxobj *xi, cg_var *cv);
int snmp_agent_check(void);
int snmp_agent_cleanup(void);
#endif /* _SNMP_LIB_H_ */

220
apps/snmp/snmp_main.c
View file

@ -30,6 +30,13 @@
the terms of any one of the Apache License version 2 or the GPL.
***** END LICENSE BLOCK *****
* This is the clixon_snmp daemon
* It assumes a netsnmp damon is running.
* - If netsnmp does not run, clixon_snmp will not start
* - If netsnmp dies, clixon_snmp will exit
* - If netsnmp is restarted, so should clixon_snmp be
* It is possible to be more resilient, such as setting a timer and trying again, in fact, libnetsnmp
* has some such mechanisms
*/
#ifdef HAVE_CONFIG_H
@ -56,11 +63,15 @@
/* clicon */
#include <clixon/clixon.h>
#include "snmp_lib.h"
#include "snmp_register.h"
/* Command line options to be passed to getopt(3) */
#define SNMP_OPTS "hD:f:l:o:z"
/* Forward */
static int clixon_snmp_input_cb(int s, void *arg);
/*! Return (hardcoded) pid file
*/
static char*
@ -84,6 +95,87 @@ clixon_snmp_sig_term(int arg)
clixon_exit_set(1);
}
/*! Clean and close all state of netconf process (but dont exit).
* Cannot use h after this
* @param[in] h Clixon handle
*/
static int
snmp_terminate(clicon_handle h)
{
yang_stmt *yspec;
cvec *nsctx;
cxobj *x;
char *pidfile = clicon_snmp_pidfile(h);
snmp_shutdown(__FUNCTION__);
shutdown_agent();
snmp_agent_cleanup();
clicon_rpc_close_session(h);
if ((yspec = clicon_dbspec_yang(h)) != NULL)
ys_free(yspec);
if ((yspec = clicon_config_yang(h)) != NULL)
ys_free(yspec);
if ((nsctx = clicon_nsctx_global_get(h)) != NULL)
cvec_free(nsctx);
if ((x = clicon_conf_xml(h)) != NULL)
xml_free(x);
xpath_optimize_exit();
clixon_event_exit();
clicon_handle_exit(h);
clixon_err_exit();
clicon_log_exit();
if (pidfile)
unlink(pidfile);
return 0;
}
/*! Get which sockets are used from SNMP API, the register single sockets into clixon event system
*
* @param[in] h Clixon handle
* @param[in] register if 1 register snmp sockets with event handler. If 0 close and unregister
* This is a workaround for netsnmps API usiing fdset:s, instead an fdset is created before calling
* the snmp api
* if you use select(), see snmp_select_info() in snmp_api(3)
* snmp_select_info(int *numfds, fd_set *fdset, struct timeval *timeout, int *block)
* @see clixon_snmp_input_cb
*/
static int
clixon_snmp_fdset_register(clicon_handle h,
int regfd)
{
int retval = -1;
int numfds = 0;
fd_set readfds;
struct timeval timeout = { LONG_MAX, 0 };
int block = 0;
int nr;
int s;
FD_ZERO(&readfds);
if ((nr = snmp_sess_select_info(NULL, &numfds, &readfds, &timeout, &block)) < 0){
clicon_err(OE_XML, errno, "snmp_select_error");
goto done;
}
/* eg 4, 6, 8 */
for (s=0; s<numfds; s++){
if (FD_ISSET(s, &readfds)){
clicon_debug(1, "%s %d", __FUNCTION__, s);
if (regfd){
if (clixon_event_reg_fd(s, clixon_snmp_input_cb, h, "snmp socket") < 0)
goto done;
}
else{
if (clixon_event_unreg_fd(s, clixon_snmp_input_cb) < 0)
goto done;
close(s);
}
}
}
retval = 0;
done:
return retval;
}
/*! Callback for single socket
* This is a workaround for netsnmps API usiing fdset:s, instead an fdset is created before calling
* the snmp api
@ -94,47 +186,37 @@ static int
clixon_snmp_input_cb(int s,
void *arg)
{
int retval = -1;
fd_set readfds;
// clicon_handle h = (clicon_handle)arg;
int retval = -1;
fd_set readfds;
clicon_handle h = (clicon_handle)arg;
int ret;
clicon_debug(2, "%s", __FUNCTION__);
clicon_debug(1, "%s %d", __FUNCTION__, s);
FD_ZERO(&readfds);
FD_SET(s, &readfds);
snmp_read(&readfds);
retval = 0;
// done:
return retval;
}
/*! Get which sockets are used from SNMP API, the register single sockets into clixon event system
*
* This is a workaround for netsnmps API usiing fdset:s, instead an fdset is created before calling
* the snmp api
* if you use select(), see snmp_select_info() in snmp_api(3)
* snmp_select_info(int *numfds, fd_set *fdset, struct timeval *timeout, int *block)
* @see clixon_snmp_input_cb
*/
static int
clixon_snmp_fdset_register(clicon_handle h)
{
int retval = -1;
int numfds = 0;
fd_set readfds;
struct timeval timeout = { LONG_MAX, 0 };
int block = 0;
int nr;
int i;
FD_ZERO(&readfds);
if ((nr = snmp_sess_select_info(NULL, &numfds, &readfds, &timeout, &block)) < 0){
clicon_err(OE_XML, errno, "snmp_select_error");
goto done;
}
for (i=0; i<numfds; i++){
if (FD_ISSET(i, &readfds)){
if (clixon_event_reg_fd(i, clixon_snmp_input_cb, h, "snmp socket") < 0)
(void)snmp_read(&readfds);
if (clixon_event_poll(s) < 0){
if (errno == EBADF){
clicon_err_reset();
/* Close the active socket */
if (clixon_event_unreg_fd(s, clixon_snmp_input_cb) < 0)
goto done;
close(s);
/* and then the others */
if (clixon_snmp_fdset_register(h, 0) < 0)
goto done;
if ((ret = snmp_close_sessions()) != 1){
clicon_err(OE_SNMP, ret, "snmp_close_sessions");
goto done;
}
/* Signal normal exit to upper layers (=event handling)
* One can signal error and return -1, but it is nicer with an orderly exit
*/
clixon_exit_set(1);
}
else {
clicon_err(OE_UNIX, errno, "poll");
goto done;
}
}
retval = 0;
@ -142,14 +224,15 @@ clixon_snmp_fdset_register(clicon_handle h)
return retval;
}
/*! Init netsnmp agent connection
* @param[in] h Clixon handle
* @param[in] logdst Log destination, see clixon_log.h
* @see snmp_terminate
*/
static int
clixon_snmp_subagent(clicon_handle h,
int logdst)
clixon_snmp_init_subagent(clicon_handle h,
int logdst)
{
int retval = -1;
char *sockpath = NULL;
@ -159,8 +242,17 @@ clixon_snmp_subagent(clicon_handle h,
snmp_enable_calllog();
else
snmp_enable_stderrlog();
/* make a agentx client. */
netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, NETSNMP_DS_AGENT_ROLE, 1);
/* 0 if master, 1 if client */
netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, NETSNMP_DS_AGENT_ROLE, 1);
/* don't load config and don't load/save persistent file */
netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_DONT_PERSIST_STATE, 1);
/* don't load persistent file */
netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_DISABLE_PERSISTENT_LOAD, 1);
/* don't save persistent file */
netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_DISABLE_PERSISTENT_SAVE, 1);
if (clicon_debug_get())
netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, NETSNMP_DS_AGENT_VERBOSE, 1);
if ((sockpath = clicon_option_str(h, "CLICON_SNMP_AGENT_SOCK")) == NULL){
clicon_err(OE_XML, 0, "CLICON_SNMP_AGENT_SOCK not set");
@ -169,13 +261,17 @@ clixon_snmp_subagent(clicon_handle h,
/* XXX: This should be configurable. */
netsnmp_ds_set_string(NETSNMP_DS_APPLICATION_ID, NETSNMP_DS_AGENT_X_SOCKET, sockpath);
/* initialize the agent library */
init_agent(__PROGRAM__);
/* example-demon will be used to read example-demon.conf files. */
init_snmp(__PROGRAM__);
if (!snmp_agent_check()){
clicon_err(OE_DAEMON, 0, "Connection to SNMP agent failed");
goto done;
}
if (set_signal(SIGTERM, clixon_snmp_sig_term, NULL) < 0){
clicon_err(OE_DAEMON, errno, "Setting signal");
goto done;
@ -188,8 +284,8 @@ clixon_snmp_subagent(clicon_handle h,
clicon_err(OE_UNIX, errno, "Setting SIGPIPE signal");
goto done;
}
/* Workaround for netsnmps API use of fdset:s instead of sockets */
if (clixon_snmp_fdset_register(h) < 0)
/* Workaround for netsnmps API use of fdset:s instead of sockets */
if (clixon_snmp_fdset_register(h, 1) < 0)
goto done;
retval = 0;
done:
@ -226,37 +322,6 @@ clixon_snmp_err_cb(void *handle,
return 0;
}
/*! Clean and close all state of netconf process (but dont exit).
* Cannot use h after this
* @param[in] h Clixon handle
*/
static int
snmp_terminate(clicon_handle h)
{
yang_stmt *yspec;
cvec *nsctx;
cxobj *x;
char *pidfile = clicon_snmp_pidfile(h);
shutdown_agent();
clicon_rpc_close_session(h);
if ((yspec = clicon_dbspec_yang(h)) != NULL)
ys_free(yspec);
if ((yspec = clicon_config_yang(h)) != NULL)
ys_free(yspec);
if ((nsctx = clicon_nsctx_global_get(h)) != NULL)
cvec_free(nsctx);
if ((x = clicon_conf_xml(h)) != NULL)
xml_free(x);
xpath_optimize_exit();
clixon_event_exit();
clicon_handle_exit(h);
clixon_err_exit();
clicon_log_exit();
if (pidfile)
unlink(pidfile);
return 0;
}
/*! Usage help routine
* @param[in] h Clixon handle
@ -487,16 +552,13 @@ main(int argc,
goto done;
clicon_session_id_set(h, id);
/* Init snmp as subagent */
if (clixon_snmp_subagent(h, logdst) < 0)
if (clixon_snmp_init_subagent(h, logdst) < 0)
goto done;
/* Init and traverse mib-translated yangs and register callbacks */
if (clixon_snmp_traverse_mibyangs(h) < 0)
goto done;
/* Write pid-file */
if (pidfile_write(pidfile) < 0)

17
apps/snmp/snmp_register.c
View file

@ -182,7 +182,11 @@ mibyang_leaf_register(clicon_handle h,
netsnmp_handler_free(handler);
goto done;
}
handler->myvoid =(void*)sh;
/* Register our application data and how to free it */
handler->myvoid = (void*)sh;
handler->data_clone = snmp_handle_clone;
handler->data_free = snmp_handle_free;
/*
* XXX: nhreg->agent_data
*/
@ -231,7 +235,7 @@ mibyang_table_register(clicon_handle h,
clixon_snmp_handle *sh;
int ret;
netsnmp_mib_handler *handler;
netsnmp_table_registration_info *table_info=NULL;
netsnmp_table_registration_info *table_info = NULL;
cvec *cvk = NULL; /* vector of index keys */
cg_var *cvi;
char *keyname;
@ -274,7 +278,11 @@ mibyang_table_register(clicon_handle h,
netsnmp_handler_free(handler);
goto done;
}
/* Register our application data and how to free it */
handler->myvoid =(void*)sh;
handler->data_clone = snmp_handle_clone;
handler->data_free = snmp_handle_free;
/* See netsnmp_register_table_data_set */
if ((table_info = SNMP_MALLOC_TYPEDEF(netsnmp_table_registration_info)) == NULL){
clicon_err(OE_UNIX, errno, "SNMP_MALLOC_TYPEDEF");
@ -320,6 +328,7 @@ mibyang_table_register(clicon_handle h,
clicon_err(OE_SNMP, ret, "netsnmp_register_table");
goto done;
}
sh->sh_table_info = table_info;
clicon_debug(1, "%s %s registered", __FUNCTION__, oidstr);
ok:
retval = 0;
@ -346,7 +355,7 @@ mibyang_table_traverse_static(clicon_handle h,
{
int retval = -1;
cvec *nsc = NULL;
char *xpath;
char *xpath = NULL;
cxobj *xt = NULL;
cxobj *xerr;
cxobj *xtable;
@ -408,6 +417,8 @@ mibyang_table_traverse_static(clicon_handle h,
}
retval = 0;
done:
if (xpath)
free(xpath);
if (cvk)
cvec_free(cvk);
if (xt)

3
test/lib.sh
View file

@ -190,6 +190,9 @@ BUSER=clicon
: ${clixon_snmp_pidfile:="/var/tmp/clixon_snmp.pid"}
# Temporary debug var, set to trigger remaining snmp errors
: ${snmp_debug:=false}
# Source the site-specific definitions for test script variables, if site.sh
# exists. The variables defined in site.sh override any variables of the same
# names in the environment in the current execution.

3
test/test_snmp_get.sh
View file

@ -250,7 +250,8 @@ validate_oid $NAME12 $NAME12 "INTEGER" 1
new "Get bulk OIDs"
expectpart "$($snmpbulkget $OID1)" 0 "$OID2 = INTEGER: -1" "$OID3 = STRING: \"This is not default\"" "$OID4 = Timeticks: (12345) 0:02:03.45" "$OID5 = INTEGER: 48" "$OID6 = Gauge32: 123123123" "$OID7 = INTEGER: 3" "$OID8 = Counter32: 123456" "$OID9 = Counter64: 4294967296" "$OID10 = INTEGER: 1" "$OID11 = Timeticks: (1234567890) 142 days, 21:21:18.90"
if [ $snmp_debug ]; then
snmp_debug=false
if $snmp_debug; then
new "Test SNMP table netSnmpIETFWGTable"
expectpart "$($snmptable $OID13)" 0 "Name1" "Name2"