neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-hnbgw/+/36485?usp=email ) Change subject: use json to decode counters from nftables ...................................................................... use json to decode counters from nftables Switch nft output to json. Add libjansson dependency, and use it to parse the result. Navigate the json tree to retrieve the counter values. Parsing with json takes longer than the direct string parsing of nft language, but it is the more correct and more stable approach: in case nftables changes its API, json is likely to still be compatible. Related: SYS#6773 Change-Id: Id4e7fa017c31945388a010d8581715d71482116b --- M configure.ac M src/osmo-hnbgw/nft_kpi.c 2 files changed, 115 insertions(+), 72 deletions(-) git pull ssh://gerrit.osmocom.org:29418/osmo-hnbgw refs/changes/85/36485/1 diff --git a/configure.ac b/configure.ac index bea9a76..657ad0d 100644 --- a/configure.ac +++ b/configure.ac @@ -60,6 +60,7 @@ PKG_CHECK_MODULES(LIBOSMOHNBAP, libosmo-hnbap >= 1.5.0) PKG_CHECK_MODULES(LIBOSMOMGCPCLIENT, libosmo-mgcp-client >= 1.12.0) PKG_CHECK_MODULES(LIBNFTABLES, libnftables >= 1.0.2) +PKG_CHECK_MODULES(LIBJANSSON, jansson >= 2.14) # Enable PFCP support for GTP tunnel mapping via UPF AC_ARG_ENABLE([pfcp], [AS_HELP_STRING([--enable-pfcp], [Build with PFCP support, for GTP tunnel mapping via UPF])], diff --git a/src/osmo-hnbgw/nft_kpi.c b/src/osmo-hnbgw/nft_kpi.c index 0dd702f..0b5ac91 100644 --- a/src/osmo-hnbgw/nft_kpi.c +++ b/src/osmo-hnbgw/nft_kpi.c @@ -19,6 +19,7 @@ #include <ctype.h> #include <inttypes.h> +#include <jansson.h> #include <nftables/libnftables.h> #include <osmocom/core/logging.h> @@ -51,7 +52,7 @@ OSMO_ASSERT(false); } - nft_ctx_output_set_flags(s->nft.nft_ctx, NFT_CTX_OUTPUT_HANDLE); + nft_ctx_output_set_flags(s->nft.nft_ctx, NFT_CTX_OUTPUT_JSON); return s->nft.nft_ctx; } @@ -219,99 +220,123 @@ &val->bytes, bytes); } -/* In the string section *pos .. end, find the first occurence of after_str and return the following token, which ends - * by a space or at end. If end is NULL, search until the '\0' termination of *pos. - * Return true if after_str was found, copy the following token into buf, and in *pos, return the position just after - * that token. */ -static bool get_token_after(char *buf, size_t buflen, const char **pos, const char *end, const char *after_str) +static int hnb_update_counters_by_id(const char *id_str, bool ul, int64_t packets, int64_t bytes, int64_t handle, + struct hnb_persistent **last_hnbp) { - const char *found = strstr(*pos, after_str); - const char *token_end; - size_t token_len; - if (!found) - return false; - if (end && found >= end) { - *pos = end; - return false; + struct hnb_persistent *hnbp; + LOGP(DNFT, LOGL_DEBUG, "%s(%s, %s, %"PRId64", %"PRId64", %"PRId64")\n", __func__, + id_str, ul ? "ul" : "dl", packets, bytes, handle); + + /* Half the time, we already have a pointer to the correct hnb */ + if (last_hnbp && *last_hnbp && !strcmp((*last_hnbp)->id_str, id_str)) + hnbp = *last_hnbp; + else + hnbp = hnb_persistent_find_by_id_str(id_str); + if (!hnbp) { + LOGP(DNFT, LOGL_DEBUG, "%s(): cannot update counters, hNodeB not found: %s\n", __func__, id_str); + return -ENOENT; } - found += strlen(after_str); - while (*found && *found == ' ' && (!end || found < end)) - found++; - token_end = found; - while (*token_end != ' ' && (!end || token_end < end)) - token_end++; - if (token_end <= found) { - *pos = found; - return false; - } - if (*found == '"' && token_end > found + 1 && *(token_end - 1) == '"') { - found++; - token_end--; - } - token_len = token_end - found; - token_len = OSMO_MIN(token_len, buflen - 1); - memcpy(buf, found, token_len); - buf[token_len] = '\0'; - *pos = token_end; - return true; + if (last_hnbp) + *last_hnbp = hnbp; + hnb_update_counters(hnbp, ul, packets, bytes, handle); + return 0; } static void decode_nft_response(const char *response) { struct nft_kpi_state *s = &g_nft_kpi_state; - const char *pos; - char buf[128]; + struct hnb_persistent *hnbp = NULL; + json_t *json; + json_error_t json_err; + + json_t *nftables; + json_t *item; + int i; int count = 0; - /* find and parse all occurences of strings like: - * [...] counter packets 3 bytes 129 comment "ul:001-01-L2-R3-S4-C1" # handle 10 - */ - pos = response; - while (*pos) { - const char *line_end; - int64_t packets; - int64_t bytes; - int64_t handle = 0; + json = json_loads(response, 0, &json_err); + if (!json) + goto json_err; + + nftables = json_object_get(json, "nftables"); + + if (!json_is_array(nftables)) + goto json_inval; + + json_array_foreach (nftables, i, item) { + json_t *rule = json_object_get(item, "rule"); + json_t *handle; + json_t *comment; + json_t *expr; + json_t *expr_item; + json_t *packets; + json_t *bytes; bool ul; - struct hnb_persistent *hnbp; + json_t *counter = NULL; + int j; + const char *comment_str; + const char *hnb_id; - if (!get_token_after(buf, sizeof(buf), &pos, NULL, "counter packets ")) - break; - if (osmo_str_to_int64(&packets, buf, 10, 0, INT64_MAX)) - break; - line_end = strchr(pos, '\n'); - if (!line_end) - line_end = pos + strlen(pos); + if (!rule) + continue; - if (!get_token_after(buf, sizeof(buf), &pos, line_end, "bytes ")) - break; - if (osmo_str_to_int64(&bytes, buf, 10, 0, INT64_MAX)) - break; + comment = json_object_get(rule, "comment"); + if (!comment || !json_is_string(comment)) + continue; - if (!get_token_after(buf, sizeof(buf), &pos, line_end, "comment ")) - break; + handle = json_object_get(rule, "handle"); + if (!handle || !json_is_integer(handle)) + continue; - if (osmo_str_startswith(buf, "ul:")) + expr = json_object_get(rule, "expr"); + if (!json_is_array(expr)) + continue; + json_array_foreach (expr, j, expr_item) { + counter = json_object_get(expr_item, "counter"); + if (counter && !json_is_object(counter)) + counter = NULL; + if (counter) + break; + } + + if (!counter) + continue; + + packets = json_object_get(counter, "packets"); + if (!packets || !json_is_integer(packets)) + continue; + bytes = json_object_get(counter, "bytes"); + if (!bytes || !json_is_integer(bytes)) + continue; + + comment_str = json_string_value(comment); + if (osmo_str_startswith(comment_str, "ul:")) ul = true; - else if (osmo_str_startswith(buf, "dl:")) + else if (osmo_str_startswith(comment_str, "dl:")) ul = false; else - break; + continue; + hnb_id = comment_str + 3; - hnbp = hnb_persistent_find_by_id_str(buf + 3); - if (!hnbp) - break; - - if (!get_token_after(buf, sizeof(buf), &pos, line_end, "# handle ")) - break; - if (osmo_str_to_int64(&handle, buf, 10, 0, INT64_MAX)) - break; - - hnb_update_counters(hnbp, ul, packets, bytes, handle); + if (hnb_update_counters_by_id(hnb_id, + ul, + json_integer_value(packets), + json_integer_value(bytes), + json_integer_value(handle), + &hnbp)) + continue; count++; } LOGP(DNFT, LOGL_DEBUG, "read %d counters from nft table %s\n", count, s->nft.table_name); + return; + +json_err: + LOGP(DNFT, LOGL_ERROR, "failed to decode nft response: %d: %s\n", + json_err.line, json_err.text); + return; +json_inval: + LOGP(DNFT, LOGL_ERROR, "unexpected structure in nft response\n"); } void nft_kpi_read_counters(void) -- To view, visit https://gerrit.osmocom.org/c/osmo-hnbgw/+/36485?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: osmo-hnbgw Gerrit-Branch: master Gerrit-Change-Id: Id4e7fa017c31945388a010d8581715d71482116b Gerrit-Change-Number: 36485 Gerrit-PatchSet: 1 Gerrit-Owner: neels &lt;nhofmeyr(a)sysmocom.de&gt; Gerrit-MessageType: newchange