Re: [libvirt PATCHv2 10/15] nss: convert findLeases to use json-c

While the parsing is still done by 1K buffers, the results are no longer filtered during the parsing, but the whole JSON has to live in memory at once, which was also the case before the NSS plugin dropped its dependency on libvirt_util. Also, the new parser might be more forgiving of missing elements. Signed-off-by: Ján Tomko <jtomko(a)redhat.com&gt; --- tools/nss/libvirt_nss_leases.c | 370 +++++++++++---------------------- 1 file changed, 119 insertions(+), 251 deletions(-)

@@ -156,190 +128,120 @@ appendAddr(const char *name __attribute__((unused)), }

+/** + * findLeaseInJSON + * + * @jobj: the json object containing the leases + * @name: the requested hostname (optional if a MAC address is present) + * @macs: the array of MAC addresses we're matching (optional if we have a hostname) + * @nmacs: the size of the MAC array + * @af: the requested address family + * @now: current time (to eliminate expired leases) + * @addrs: the returned matching addresses + * @naddrs: size of the returned array + * @found: whether a match was found + * + * Returns 0 even if nothing was found + * -1 on error + */ static int +findLeaseInJSON(json_object *jobj, + const char *name, + char **macs, + size_t nmacs, + int af, + time_t now, + leaseAddress **addrs, + size_t *naddrs, + bool *found) { size_t i; + int len; + if (!json_object_is_type(jobj, json_type_array)) { + ERROR("parsed JSON does not contain the leases array"); + return -1; } + len = json_object_array_length(jobj); + for (i = 0; i < len; i++) { + json_object *lease = NULL; + json_object *expiry = NULL; + json_object *ipobj = NULL; + unsigned long long expiryTime; + const char *ipaddr; + + lease = json_object_array_get_idx(jobj, i); + + if (macs) { + const char *macAddr; + bool match = false; + json_object *val; + size_t j; + + val = json_object_object_get(lease, "mac-address"); + if (!val) + continue; + + macAddr = json_object_get_string(val); + if (!macAddr) + continue; + + for (j = 0; j < nmacs; j++) { + if (!strcmp(macs[j], macAddr)) {

+ match = true; + break; + } + } + if (!match) + continue; + } else { + const char *leaseName; + json_object *val; + + val = json_object_object_get(lease, "hostname"); + if (!val) + continue; + + leaseName = json_object_get_string(val); + if (!leaseName) + continue; + + if (strcasecmp(leaseName, name) != 0) + continue; + } + expiry = json_object_object_get(lease, "expiry-time"); + if (!expiry) { + ERROR("Missing expiry time for %s", name); + return -1; + } + expiryTime = json_object_get_uint64(expiry); + if (expiryTime > 0 && expiryTime < now) { + DEBUG("Skipping expired lease for %s", name); + continue; + } + ipobj = json_object_object_get(lease, "ip-address"); + if (!ipobj) { + DEBUG("Missing IP address for %s", name); + continue; + } + ipaddr = json_object_get_string(ipobj); + DEBUG("Found record for %s", name); + *found = true; + if (appendAddr(name, + addrs, naddrs, + ipaddr, + expiryTime, + af) < 0) + return -1; } + return 0; }

@@ -356,30 +258,10 @@ findLeases(const char *file, { int fd = -1; int ret = -1; + json_object *jobj = NULL; + json_tokener *tok = NULL; + enum json_tokener_error jerr; + int jsonflags = JSON_TOKENER_STRICT | JSON_TOKENER_VALIDATE_UTF8; char line[1024]; ssize_t nreadTotal = 0; int rv; @@ -389,51 +271,37 @@ findLeases(const char *file, goto cleanup; } + tok = json_tokener_new(); + json_tokener_set_flags(tok, jsonflags); + do { + rv = read(fd, line, sizeof(line) - 1);

if (rv < 0) goto cleanup; if (rv == 0) break;

nreadTotal += rv; + jobj = json_tokener_parse_ex(tok, line, rv); + jerr = json_tokener_get_error(tok); + } while (jerr == json_tokener_continue); + if (nreadTotal > 0 && jerr != json_tokener_success) {

+ ERROR("Cannot parse %s: %s", file, json_tokener_error_desc(jerr));

goto cleanup; } + ret = findLeaseInJSON(jobj, name, macs, nmacs, af, now, + addrs, naddrs, found); cleanup: + json_object_put(jobj); + json_tokener_free(tok); if (ret != 0) { free(*addrs); *addrs = NULL; *naddrs = 0; } if (fd != -1) close(fd); return ret;