Add: support for nasl snmp getnext #1047

Kraemii · 2022-02-24T19:14:52Z

What:
Additional Nasle function to support GETNEXT for SNMP.
SC-443

Why:
This allows to iterate over OID trees

How:
Currently in testing phase

Used this script for testing:

########## begin script ####################
include("misc_func.inc");
include("dump.inc");


oid = '1.3.6.1.2.1.1.1.0';

## uncomment this line to test the error handling
#oid = '.1.3.6.1.2.1.1.1.0.3.3.3.3';
protocol = 'udp';
port = 161;
community = 'public';

display("Iterrate trough SNMP OID tree");
ret = snmpv1_get( port:port, oid:oid, protocol:protocol, community:community );
display (ret, "\n");
retry = 100;
while(ret[0] == 0 && retry > 0)
{
    retry = retry - 1;
    ret = snmpv1_getnext( port:port, oid:ret[2], protocol:protocol, community:community );
    display (ret, "\n");
}


############# end script ########################

Checklist:

Tests
PR merge commit message adjusted

nasl/nasl_snmp.c

Kraemii · 2022-03-21T13:19:11Z

nasl/nasl_snmp.c

+  /* Free request only, since members are pointers to the nasl lexic context
+     which will be free()'d later */
+  g_free (request);
+
  return array_from_snmp_result (ret, result);


I guess the result struct also has to free its memory after the array is created

No. Result struct must not be free()'d, since the return nasl tree_cell structs does not have a copy of the result members, but points to them. You can see this in the array_from_snmp_result().
Once the script finishes, the memory used by tree_cells structures is released.

Kraemii · 2022-03-21T13:19:25Z

nasl/nasl_snmp.c

+  /* Free request only, since members are pointers to the nasl lexic context
+     which will be free()'d later */
+  g_free (request);
+
  return array_from_snmp_result (ret, result);


same as above

Now is called nasl_snmpv3_get_action() and receives the new parameter "action" to specify if it will be called the "get" or "getnext" action. Add wrappers for this function which call nasl_snmpv3_get_action() with the requiered action.

…arameter "action". Pass the new action parameter set with NASL_SNMP_GET in the existing nasl_snmpv*_get() wrapper functions Add the new wrapper functions nasl_snmpv1_getnext() and nasl_snmpv2c_getnext()

…tion var

This fixes a segmentation fault in the original PR, because result didn't have allocated memory.

The first time the oid is requiered. The next time, the oid is optional for getnext While snmpgetnext support mib descriptions instead of oids (like iso.3.6....), the older version snmp v1 doesn't. Therfore the iso. is formated in the right place, so the oid can be saved once it is in the result.

Now, also the oid is get with name.

…he result struct. The oid can be used now for getnext. (See some commits above.)

Kraemii force-pushed the snmp-getnext branch 4 times, most recently from 52a8ed3 to 3144979 Compare February 28, 2022 08:21

jjnicola force-pushed the snmp-getnext branch from 3144979 to 793073a Compare March 9, 2022 10:06

jjnicola marked this pull request as ready for review March 9, 2022 10:13

jjnicola requested a review from a team as a code owner March 9, 2022 10:13

jjnicola force-pushed the snmp-getnext branch from 8fc3468 to fdef6db Compare March 14, 2022 07:09

jjnicola enabled auto-merge (squash) March 14, 2022 07:11

jjnicola added the backport-to-middleware label Mar 14, 2022

Kraemii commented Mar 17, 2022

View reviewed changes

nasl/nasl_snmp.c Show resolved Hide resolved

Kraemii commented Mar 17, 2022

View reviewed changes

nasl/nasl_snmp.c Show resolved Hide resolved

jjnicola force-pushed the snmp-getnext branch from fdef6db to a74e981 Compare March 18, 2022 08:10

Kraemii commented Mar 21, 2022

View reviewed changes

ArnoStiefvater approved these changes Mar 28, 2022

View reviewed changes

jjnicola added 14 commits March 28, 2022 08:39

Add prototypes and make the functions available

74399e2

Add comments and update docstrings

5ab8cbe

Rework nasl_snmpv3_get().

45fa026

Now is called nasl_snmpv3_get_action() and receives the new parameter "action" to specify if it will be called the "get" or "getnext" action. Add wrappers for this function which call nasl_snmpv3_get_action() with the requiered action.

Modify nasl_snmpv1v2c_get () function signature. Now receives a new p…

2c56ed1

…arameter "action". Pass the new action parameter set with NASL_SNMP_GET in the existing nasl_snmpv*_get() wrapper functions Add the new wrapper functions nasl_snmpv1_getnext() and nasl_snmpv2c_getnext()

Add log domain

a2f9cee

Define snmp versions

83d9df8

Add request struct for snmp v1 and v2c

6cc873b

Add request struct for snmp v3

bcb8c87

Use snmpv3_request struct in nasl_snmpv3_get_action. Also uses the ac…

0d12203

…tion var

Use snmpv3_request struct in snmpv3_get().

1ecfb72

Use snmpv3_request struct in snmpv3_get() (cmd wrap-up).

c81b5df

Add definition for action. Depends on the method, cmd wrapper or library

8701147

Use snmpv1v2_request struct in nasl_snmpv1v2c_get(). Also uses the ac…

6a31ed3

…tion var

Use snmpv1v2_request struct in snmpv1v2c_get() (cmd wrap-up).

af47ff7

jjnicola added 19 commits March 28, 2022 08:39

Use snmpv1v2_request struct in snmpv1v2c_get() (libnet-snmp)

3886ff3

Receive and use the action param in snmp_get()

29b33e2

Add struct snmp_result

e2c580a

Change array_from_smmp_result() to use the new struct snmp_result

cbd26f1

Add array_from_snmp_error()

256be49

Use snmp_result struct where necessary

97a897b

Adjust format

15689fc

Define new type snmp_result_t for snmp_result*

41b2a40

Use the new type for results, and allocate memory for results

148adef

This fixes a segmentation fault in the original PR, because result didn't have allocated memory.

Define new type snmpv1v2_request_t for struct snmpv1v2_request*

2c2378d

Use the new type and allocate memory for the request struct

ef014ca

Define new type snmpv3_request_t for struct snmpv3_request*

5bb8155

Use snmpv3_request_t and allocate memory for the request struct

530ac0d

Adjust format again

8da4858

Get the oid also in the result for the snmp cmd wrapper

bb0bd28

Now, also the oid is get with name.

Parse the result (snmp cmd wrapper), and stores the oid and name in t…

df3a7a3

…he result struct. The oid can be used now for getnext. (See some commits above.)

Adjust format one more time

ebbfde4

Free memory allocated for request

7982a46

ArnoStiefvater force-pushed the snmp-getnext branch from d9db3a5 to 7982a46 Compare March 28, 2022 06:40

ArnoStiefvater removed the backport-to-middleware label Mar 28, 2022

ArnoStiefvater disabled auto-merge March 28, 2022 06:43

ArnoStiefvater merged commit 0bbf047 into greenbone:main Mar 28, 2022

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Add: support for nasl snmp getnext #1047

Add: support for nasl snmp getnext #1047

Kraemii commented Feb 24, 2022 •

edited

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Kraemii Mar 21, 2022

jjnicola Mar 28, 2022

Kraemii Mar 21, 2022

Add: support for nasl snmp getnext #1047

Add: support for nasl snmp getnext #1047

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Kraemii commented Feb 24, 2022 • edited Loading

Kraemii Mar 21, 2022

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Kraemii commented Feb 24, 2022 •

edited

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