As discussed with semarie@ this morning: We're a bit too loose when it
comes to accessing indexes based directly from the pdu.
Diff below allows only indexes within the range of the pdu.
If user supplied oid and returned oid on index match the user supplied
input is shown (for easier reference). If they don't match then show
the oid based on the -O flag. If the index is out of range throw an
additional error message and show a "?".
Since it apparently is hard to get a proper error status with the
daemons available to me, this is only compile tested. Testers welcome.
This also adds a missing NULL-check, which could be committed
separately.
OK?
martijn@
Index: snmpc.c
===================================================================
RCS file: /cvs/src/usr.bin/snmp/snmpc.c,v
retrieving revision 1.13
diff -u -p -r1.13 snmpc.c
--- snmpc.c 3 Oct 2019 11:02:26 -0000 1.13
+++ snmpc.c 3 Oct 2019 15:30:50 -0000
@@ -52,7 +52,8 @@ int snmpc_mibtree(int, char *[]);
struct snmp_agent *snmpc_connect(char *, char *);
int snmpc_parseagent(char *, char *);
int snmpc_print(struct ber_element *);
-__dead void snmpc_printerror(enum snmp_error, char *);
+__dead void snmpc_printerror(enum snmp_error, struct ber_element *, int,
+ const char *);
char *snmpc_hex2bin(char *, size_t *);
struct ber_element *snmpc_varbindparse(int, char *[]);
void usage(void);
@@ -480,6 +481,7 @@ snmpc_get(int argc, char *argv[])
int i;
int class;
unsigned type;
+ char *hint = NULL;
if (argc < 2)
usage();
@@ -519,9 +521,12 @@ snmpc_get(int argc, char *argv[])
(void) ber_scanf_elements(pdu, "t{Sdd{e", &class, &type, &errorstatus,
&errorindex, &varbind);
- if (errorstatus != 0)
- snmpc_printerror((enum snmp_error) errorstatus,
- argv[errorindex - 1]);
+ if (errorstatus != 0) {
+ if (errorindex >= 1 && errorindex <= argc)
+ hint = argv[errorindex - 1];
+ snmpc_printerror((enum snmp_error) errorstatus, varbind,
+ errorindex, hint);
+ }
if (class == BER_CLASS_CONTEXT && type == SNMP_C_REPORT)
printf("Received report:\n");
@@ -542,7 +547,6 @@ snmpc_walk(int argc, char *argv[])
struct timespec start, finish;
struct snmp_agent *agent;
const char *oids;
- char oidstr[SNMP_MAX_OID_STRLEN];
int n = 0, prev_cmp;
int errorstatus, errorindex;
int class;
@@ -574,8 +578,8 @@ snmpc_walk(int argc, char *argv[])
(void) ber_scanf_elements(pdu, "t{Sdd{e", &class, &type,
&errorstatus, &errorindex, &varbind);
if (errorstatus != 0)
- snmpc_printerror((enum snmp_error) errorstatus,
- argv[errorindex - 1]);
+ snmpc_printerror((enum snmp_error) errorstatus, varbind,
+ errorindex, oids);
if (class == BER_CLASS_CONTEXT && type == SNMP_C_REPORT)
printf("Received report:\n");
@@ -600,9 +604,8 @@ snmpc_walk(int argc, char *argv[])
(void) ber_scanf_elements(pdu, "t{Sdd{e", &class, &type,
&errorstatus, &errorindex, &varbind);
if (errorstatus != 0) {
- smi_oid2string(&noid, oidstr, sizeof(oidstr),
- oid_lookup);
- snmpc_printerror((enum snmp_error) errorstatus, oidstr);
+ snmpc_printerror((enum snmp_error) errorstatus, varbind,
+ errorindex, NULL);
}
if (class == BER_CLASS_CONTEXT && type == SNMP_C_REPORT)
@@ -639,8 +642,8 @@ snmpc_walk(int argc, char *argv[])
(void) ber_scanf_elements(pdu, "t{Sdd{e", &class, &type,
&errorstatus, &errorindex, &varbind);
if (errorstatus != 0)
- snmpc_printerror((enum snmp_error) errorstatus,
- argv[errorindex - 1]);
+ snmpc_printerror((enum snmp_error) errorstatus, varbind,
+ errorindex, oids);
if (class == BER_CLASS_CONTEXT && type == SNMP_C_REPORT)
printf("Received report:\n");
@@ -676,6 +679,7 @@ snmpc_set(int argc, char *argv[])
int errorstatus, errorindex;
int class;
unsigned type;
+ char *hint = NULL;
if (argc < 4)
usage();
@@ -687,13 +691,17 @@ snmpc_set(int argc, char *argv[])
if (pledge("stdio", NULL) == -1)
err(1, "pledge");
- pdu = snmp_set(agent, snmpc_varbindparse(argc, argv));
+ if ((pdu = snmp_set(agent, snmpc_varbindparse(argc, argv))) == NULL)
+ err(1, "set");
(void) ber_scanf_elements(pdu, "t{Sdd{e", &class, &type, &errorstatus,
&errorindex, &varbind);
- if (errorstatus != 0)
- snmpc_printerror((enum snmp_error) errorstatus,
- argv[errorindex - 1]);
+ if (errorstatus != 0) {
+ if (errorindex >= 1 && errorindex <= argc / 3)
+ hint = argv[(errorindex - 1) * 3];
+ snmpc_printerror((enum snmp_error) errorstatus, varbind,
+ errorindex, hint);
+ }
if (class == BER_CLASS_CONTEXT && type == SNMP_C_REPORT)
printf("Received report:\n");
@@ -805,8 +813,36 @@ snmpc_print(struct ber_element *elm)
}
__dead void
-snmpc_printerror(enum snmp_error error, char *oid)
+snmpc_printerror(enum snmp_error error, struct ber_element *varbind,
+ int index, const char *hint)
{
+ struct ber_oid hoid, vboid;
+ char oids[SNMP_MAX_OID_STRLEN];
+ const char *oid = NULL;
+ int i;
+
+ if (index >= 1) {
+ /* Only print if the index is in the reply */
+ for (i = 1; varbind != NULL && i <= index;
+ varbind = varbind->be_next)
+ i++;
+ if (varbind != NULL &&
+ ber_get_oid(varbind->be_sub, &vboid) == 0) {
+ /* If user and reply conform print user input */
+ if (smi_string2oid(hint, &hoid) == 0 &&
+ ber_oid_cmp(&hoid, &vboid) == 0 &&
+ hint != NULL)
+ oid = hint;
+ else
+ oid = smi_oid2string(&vboid, oids,
+ sizeof(oids), oid_lookup);
+ }
+ }
+ if (oid == NULL) {
+ fprintf(stderr, "Invalid varbind error-index received\n");
+ oid = "?";
+ }
+
switch (error) {
case SNMP_ERROR_NONE:
errx(1, "No error, how did I get here?");
