Re: [libvirt PATCHv2 11/15] nss: convert findMACs 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_macs.c | 278 ++++++++++------------------------- 1 file changed, 80 insertions(+), 198 deletions(-) diff --git a/tools/nss/libvirt_nss_macs.c b/tools/nss/libvirt_nss_macs.c index f45d149793..281865a05b 100644 --- a/tools/nss/libvirt_nss_macs.c +++ b/tools/nss/libvirt_nss_macs.c

+/** + * findMACsFromJSON + * + * @jobj: JSON object containing the leases + * @name: requested hostname + * @macs: returned array of MAC addresses leased to the hostname + * @nmacs: size of the returned array + */ static int +findMACsFromJSON(json_object *jobj, + const char *name, + char ***macs, + size_t *nmacs) { 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); + DEBUG("Found an array of length: %zu", len); + for (i = 0; i < len; i++) { + json_object *entry = NULL; + json_object *domain = NULL; + const char *domainName; + char **tmpMacs = NULL; + size_t newmacs = 0; + json_object *macsArray = NULL; + size_t j; + + entry = json_object_array_get_idx(jobj, i); + if (!entry) + continue; + DEBUG("Processing item %zu", i); + domain = json_object_object_get(entry, "domain"); + if (!domain) + continue; + domainName = json_object_get_string(domain); + if (!domainName) + continue; + DEBUG("Processing domain %s", domainName); + if (strcasecmp(domainName, name)) + continue; + macsArray = json_object_object_get(entry, "macs"); + if (!macsArray) + continue; + newmacs = json_object_array_length(macsArray); + DEBUG("Found %zu MAC addresses", newmacs); + tmpMacs = realloc(*macs, sizeof(char *) * (*nmacs + newmacs + 1)); + if (!tmpMacs) + return -1; + *macs = tmpMacs; + for (j = 0; j < newmacs; j++) { + json_object *macobj = NULL; + char *macstr; + macobj = json_object_array_get_idx(macsArray, j); + macstr = strdup(json_object_get_string(macobj)); + if (!macstr) + return -1; + (*macs)[(*nmacs)++] = macstr; + } + } + return 0; } @@ -209,66 +119,45 @@ findMACs(const char *file, { int fd = -1; int ret = -1; char line[1024]; + json_object *jobj = NULL; + json_tokener *tok = NULL; + enum json_tokener_error jerr; + int jsonflags = JSON_TOKENER_STRICT | JSON_TOKENER_VALIDATE_UTF8; + ssize_t nreadTotal = 0; int rv; + size_t i; if ((fd = open(file, O_RDONLY)) < 0) { ERROR("Cannot open %s", 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 = findMACsFromJSON(jobj, name, macs, nmacs); cleanup: + json_object_put(jobj); + json_tokener_free(tok); if (ret != 0) { for (i = 0; i < *nmacs; i++) { char *mac = (*macs)[i];