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lldp: fix sd_lldp_save()

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Fix a bunch of needless memzero() calls, a bunch of use-after-free
regarding _cleanup_free_ and drop unused variables.

Hint: Do NOT use _cleanup_free_ for temporary strappend() helpers that are
freed multiple times. All you safe is the last free() call, which is
really not worth the trouble resetting it to NULL all the time.
This commit is contained in:
David Herrmann 2014-12-31 16:28:48 +01:00
parent 7d4866548d
commit ee14ebf211
1 changed files with 16 additions and 36 deletions
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52
src/libsystemd-network/sd-lldp.c
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@ -429,7 +429,6 @@ static void lldp_mib_objects_flush(sd_lldp *lldp) {
} }
int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) { int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) {
_cleanup_free_ char *s = NULL, *t = NULL, *k = NULL;
_cleanup_free_ char *temp_path = NULL; _cleanup_free_ char *temp_path = NULL;
_cleanup_fclose_ FILE *f = NULL; _cleanup_fclose_ FILE *f = NULL;
uint8_t *mac, *port_id, type; uint8_t *mac, *port_id, type;
@ -452,13 +451,13 @@ int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) {
HASHMAP_FOREACH(c, lldp->neighbour_mib, i) { HASHMAP_FOREACH(c, lldp->neighbour_mib, i) {
LIST_FOREACH(port, p, c->ports) { LIST_FOREACH(port, p, c->ports) {
_cleanup_free_ char *s = NULL;
char *k, *t;
r = lldp_read_chassis_id(p->packet, &type, &length, &mac); r = lldp_read_chassis_id(p->packet, &type, &length, &mac);
if (r < 0) if (r < 0)
continue; continue;
memzero(buf, LINE_MAX);
sprintf(buf, "'_Chassis=%02x:%02x:%02x:%02x:%02x:%02x' '_CType=%d' ", sprintf(buf, "'_Chassis=%02x:%02x:%02x:%02x:%02x:%02x' '_CType=%d' ",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type); mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type);
@ -467,57 +466,43 @@ int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) {
return -ENOMEM; return -ENOMEM;
r = lldp_read_port_id(p->packet, &type, &length, &port_id); r = lldp_read_port_id(p->packet, &type, &length, &port_id);
if (r < 0) { if (r < 0)
free(s);
continue; continue;
}
memzero(buf, LINE_MAX);
if (type != LLDP_PORT_SUBTYPE_MAC_ADDRESS) { if (type != LLDP_PORT_SUBTYPE_MAC_ADDRESS) {
k = strndup((char *) port_id, length -1); k = strndup((char *) port_id, length -1);
if (!k) if (!k)
return -ENOMEM; return -ENOMEM;
sprintf(buf, "'_Port=%s' '_PType=%d' ", k , type); sprintf(buf, "'_Port=%s' '_PType=%d' ", k , type);
t = strappend(s, buf);
free(k); free(k);
k = NULL;
} else { } else {
mac = port_id; mac = port_id;
sprintf(buf, "'_Port=%02x:%02x:%02x:%02x:%02x:%02x' '_PType=%d' ", sprintf(buf, "'_Port=%02x:%02x:%02x:%02x:%02x:%02x' '_PType=%d' ",
mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type); mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type);
t = strappend(s, buf);
} }
if (!t) k = strappend(s, buf);
if (!k)
return -ENOMEM; return -ENOMEM;
free(s); free(s);
s = t; s = k;
time = now(CLOCK_BOOTTIME); time = now(CLOCK_BOOTTIME);
/* Don't write expired packets */ /* Don't write expired packets */
if(time - p->until <= 0) { if (time - p->until <= 0)
free(s);
continue; continue;
}
memzero(buf, LINE_MAX);
sprintf(buf, "'_TTL=%lu' ", p->until); sprintf(buf, "'_TTL=%lu' ", p->until);
t = strappend(s, buf); k = strappend(s, buf);
if (!t) if (!k)
return -ENOMEM; return -ENOMEM;
free(s); free(s);
s = t; s = k;
r = lldp_read_system_name(p->packet, &length, &k); r = lldp_read_system_name(p->packet, &length, &k);
if (r < 0) if (r < 0)
@ -528,6 +513,7 @@ int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) {
return -ENOMEM; return -ENOMEM;
k = strjoin(s, "'_NAME=", t, "' ", NULL); k = strjoin(s, "'_NAME=", t, "' ", NULL);
free(t);
} }
if (!k) if (!k)
@ -536,28 +522,22 @@ int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) {
free(s); free(s);
s = k; s = k;
memzero(buf, LINE_MAX);
(void)lldp_read_system_capability(p->packet, &data); (void)lldp_read_system_capability(p->packet, &data);
sprintf(buf, "'_CAP=%x'", data); sprintf(buf, "'_CAP=%x'", data);
t = strappend(s, buf); k = strappend(s, buf);
if (!t) if (!k)
return -ENOMEM; return -ENOMEM;
fprintf(f, "%s\n", t);
free(s); free(s);
free(t); s = k;
fprintf(f, "%s\n", s);
} }
} }
r = 0; r = 0;
s = NULL;
t = NULL;
k = NULL;
fflush(f); fflush(f);
if (ferror(f) || rename(temp_path, lldp_file) < 0) { if (ferror(f) || rename(temp_path, lldp_file) < 0) {