[libvirt] [PATCH v4 2/6] util: Add generic API to fetch network stats from procfs
Jai Singh Rana
JaiSingh.Rana at cavium.com
Thu Jun 28 13:22:33 UTC 2018
This patch introduces virNetDevGetProcNetdevStats API for linux
which returns stats for the given interface from /proc/net/dev by
properly mapping stats entries in probed column to column header.
Tap and hostdev network devices will now be using this API.
Currently function virNetDevTapInterfaceStats which earlier fetched
stats for tap devies is modified to use above API accordingly.
Signed-off-by: Jai Singh Rana <JaiSingh.Rana at cavium.com>
---
src/libvirt_private.syms | 1 +
src/util/virnetdev.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++-
src/util/virnetdev.h | 5 ++
src/util/virnetdevtap.c | 71 +----------------
4 files changed, 208 insertions(+), 71 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 272e7426dd..0ba8cd2a14 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2289,6 +2289,7 @@ virNetDevGetName;
virNetDevGetOnline;
virNetDevGetPhysicalFunction;
virNetDevGetPhysPortID;
+virNetDevGetProcNetdevStats;
virNetDevGetPromiscuous;
virNetDevGetRcvAllMulti;
virNetDevGetRcvMulti;
diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
index b250af9e2c..69875c2e04 100644
--- a/src/util/virnetdev.c
+++ b/src/util/virnetdev.c
@@ -1541,6 +1541,198 @@ virNetDevGetVirtualFunctionInfo(const char *vfname, char **pfname,
return ret;
}
+
+/**
+ * virNetDevGetProcNetdevStats:
+ * @ifname: interface
+ * @stats: where to store statistics
+ * @swapped: whether to swap RX/TX fields
+ *
+ * Fetch RX/TX statistics for given named interface (@ifname) and
+ * store them at @stats. The returned statistics are always from
+ * domain POV. Because in some cases this means swapping RX/TX in
+ * the stats and in others this means no swapping (consider TAP
+ * vs macvtap) caller might choose if the returned stats should
+ * be @swapped or not.
+ *
+ * Returns 0 on success, -1 otherwise (with error reported).
+ */
+
+int
+virNetDevGetProcNetdevStats(const char *ifname,
+ virDomainInterfaceStatsPtr stats,
+ bool swapped)
+{
+ int ifname_len;
+ FILE *fp;
+ char line[256];
+ size_t i;
+ char *hdr1 = NULL;
+ char *hdr2 = NULL;
+ char *stats_row = NULL;
+ char **components_hdr1 = NULL;
+ char **components_hdr2 = NULL;
+ char **components_stats = NULL;
+ size_t ncomponents_hdr1 = 0;
+ size_t ncomponents_hdr2 = 0;
+ size_t ncomponents_stats = 0;
+ char **rx_hdr = NULL;
+ char **tx_hdr = NULL;
+ size_t rx_nentries, tx_nentries;
+ int rx_bytes_index = 0;
+ int rx_packets_index = 0;
+ int rx_drop_index = 0;
+ int rx_errs_index = 0;
+ int tx_bytes_index = 0;
+ int tx_packets_index = 0;
+ int tx_drop_index = 0;
+ int tx_errs_index = 0;
+ int tx_offset = 0;
+ int rx_offset = 0;
+ int ret = -1;
+
+ fp = fopen("/proc/net/dev", "r");
+ if (!fp) {
+ virReportSystemError(errno, "%s",
+ _("Could not open /proc/net/dev"));
+ return ret;
+ }
+
+ ifname_len = strlen(ifname);
+
+ /* First two lines contains headers.
+ * Process headers to match with correspondings stats.
+ */
+ if (!fgets(line, sizeof(line), fp)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Interface %s not found in /proc/net/dev"), ifname);
+ VIR_FORCE_FCLOSE(fp);
+ return ret;
+ }
+
+ if (!(hdr1 = virStringCleanExtraSpaces(line)))
+ goto cleanup;
+
+ if (!(components_hdr1 = virStringSplitCount(hdr1, "|", 0,
+ &ncomponents_hdr1)))
+ goto cleanup;
+
+ if (!fgets(line, sizeof(line), fp))
+ goto cleanup;
+
+ if (!(hdr2 = virStringCleanExtraSpaces(line)))
+ goto cleanup;
+
+ if (!(components_hdr2 = virStringSplitCount(hdr2, "|", 0,
+ &ncomponents_hdr2)))
+ goto cleanup;
+
+ if (!(rx_hdr = virStringSplitCount(components_hdr2[1], " ", 0,
+ &rx_nentries)))
+ goto cleanup;
+
+ if (!(tx_hdr = virStringSplitCount(components_hdr2[2], " ", 0,
+ &tx_nentries)))
+ goto cleanup;
+
+ if (STREQ(components_hdr1[1], "Receive")) {
+ rx_offset = 0;
+ tx_offset = rx_nentries;
+ } else {
+ rx_offset = tx_nentries;
+ tx_offset = 0;
+ }
+
+ for (i = 0; i < rx_nentries; i++) {
+ if (STREQ(rx_hdr[i], "bytes"))
+ rx_bytes_index = i + rx_offset;
+ else if (STREQ(rx_hdr[i], "packets"))
+ rx_packets_index = i + rx_offset;
+ else if (STREQ(rx_hdr[i], "errs"))
+ rx_errs_index = i + rx_offset;
+ else if (STREQ(rx_hdr[i], "drop"))
+ rx_drop_index = i + rx_offset;
+ }
+
+ for (i = 0; i < tx_nentries; i++) {
+ if (STREQ(tx_hdr[i], "bytes"))
+ tx_bytes_index = i + tx_offset;
+ else if (STREQ(tx_hdr[i], "packets"))
+ tx_packets_index = i + tx_offset;
+ else if (STREQ(tx_hdr[i], "errs"))
+ tx_errs_index = i + tx_offset;
+ else if (STREQ(tx_hdr[i], "drop"))
+ tx_drop_index = i + tx_offset;
+ }
+
+ while (fgets(line, sizeof(line), fp)) {
+ long long *stats_entries;
+
+ /* The stats line looks like:
+ * "eth0:..."
+ */
+
+ VIR_FREE(stats_row);
+ if (!(stats_row = virStringCleanExtraSpaces(line)))
+ goto cleanup;
+
+ virStringListFree(components_stats);
+ if (!(components_stats = virStringSplitCount(stats_row, " ", 0,
+ &ncomponents_stats)))
+ goto cleanup;
+
+ if (STREQLEN(components_stats[0], ifname, ifname_len)) {
+ if (VIR_ALLOC_N(stats_entries, rx_nentries + tx_nentries) < 0)
+ goto cleanup;
+
+ for (i = 1; i < (rx_nentries + tx_nentries); i++) {
+ if (virStrToLong_ll(components_stats[i], NULL, 10,
+ (stats_entries + i -1)) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Cannot parse %s stat position at '%zu'"),
+ components_stats[i], i);
+ goto cleanup;
+ }
+ }
+
+ if (swapped) {
+ stats->rx_bytes = stats_entries[tx_bytes_index];
+ stats->rx_packets = stats_entries[tx_packets_index];
+ stats->rx_errs = stats_entries[tx_errs_index];
+ stats->rx_drop = stats_entries[tx_drop_index];
+ stats->tx_bytes = stats_entries[rx_bytes_index];
+ stats->tx_packets = stats_entries[rx_packets_index];
+ stats->tx_errs = stats_entries[rx_errs_index];
+ stats->tx_drop = stats_entries[rx_drop_index];
+ } else {
+ stats->rx_bytes = stats_entries[rx_bytes_index];
+ stats->rx_packets = stats_entries[rx_packets_index];
+ stats->rx_errs = stats_entries[rx_errs_index];
+ stats->rx_drop = stats_entries[rx_drop_index];
+ stats->tx_bytes = stats_entries[tx_bytes_index];
+ stats->tx_packets = stats_entries[tx_packets_index];
+ stats->tx_errs = stats_entries[tx_errs_index];
+ stats->tx_drop = stats_entries[tx_drop_index];
+ }
+ VIR_FREE(stats_entries);
+ ret = 0;
+ break;
+ }
+ }
+ cleanup:
+ VIR_FORCE_FCLOSE(fp);
+ VIR_FREE(hdr1);
+ VIR_FREE(hdr2);
+ VIR_FREE(stats_row);
+ virStringListFree(components_hdr1);
+ virStringListFree(components_hdr2);
+ virStringListFree(components_stats);
+ virStringListFree(rx_hdr);
+ virStringListFree(tx_hdr);
+
+ return ret;
+}
+
#else /* !__linux__ */
int
virNetDevGetPhysPortID(const char *ifname ATTRIBUTE_UNUSED,
@@ -1622,7 +1814,15 @@ virNetDevSysfsFile(char **pf_sysfs_device_link ATTRIBUTE_UNUSED,
return -1;
}
-
+int
+virNetDevGetProcNetdevStats(const char *ifname ATTRIBUTE_UNUSED,
+ virDomainInterfaceStatsPtr stats ATTRIBUTE_UNUSED,
+ bool swapped ATTRIBUTE_UNUSED)
+{
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("interface stats not implemented on this platform"));
+ return -1;
+}
#endif /* !__linux__ */
#if defined(__linux__) && defined(HAVE_LIBNL) && defined(IFLA_VF_MAX)
diff --git a/src/util/virnetdev.h b/src/util/virnetdev.h
index 71eaf45e30..4fb22562bb 100644
--- a/src/util/virnetdev.h
+++ b/src/util/virnetdev.h
@@ -266,6 +266,11 @@ int virNetDevGetVirtualFunctionInfo(const char *vfname, char **pfname,
int *vf)
ATTRIBUTE_NONNULL(1);
+int virNetDevGetProcNetdevStats(const char *ifname,
+ virDomainInterfaceStatsPtr stats,
+ bool swapped)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
+
int virNetDevGetFeatures(const char *ifname,
virBitmapPtr *out)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
diff --git a/src/util/virnetdevtap.c b/src/util/virnetdevtap.c
index bd0710ad2e..f0bce5ed34 100644
--- a/src/util/virnetdevtap.c
+++ b/src/util/virnetdevtap.c
@@ -687,76 +687,7 @@ virNetDevTapInterfaceStats(const char *ifname,
virDomainInterfaceStatsPtr stats,
bool swapped)
{
- int ifname_len;
- FILE *fp;
- char line[256], *colon;
-
- fp = fopen("/proc/net/dev", "r");
- if (!fp) {
- virReportSystemError(errno, "%s",
- _("Could not open /proc/net/dev"));
- return -1;
- }
-
- ifname_len = strlen(ifname);
-
- while (fgets(line, sizeof(line), fp)) {
- long long dummy;
- long long rx_bytes;
- long long rx_packets;
- long long rx_errs;
- long long rx_drop;
- long long tx_bytes;
- long long tx_packets;
- long long tx_errs;
- long long tx_drop;
-
- /* The line looks like:
- * " eth0:..."
- * Split it at the colon.
- */
- colon = strchr(line, ':');
- if (!colon) continue;
- *colon = '\0';
- if (colon-ifname_len >= line &&
- STREQ(colon-ifname_len, ifname)) {
- if (sscanf(colon+1,
- "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld",
- &rx_bytes, &rx_packets, &rx_errs, &rx_drop,
- &dummy, &dummy, &dummy, &dummy,
- &tx_bytes, &tx_packets, &tx_errs, &tx_drop,
- &dummy, &dummy, &dummy, &dummy) != 16)
- continue;
-
- if (swapped) {
- stats->rx_bytes = tx_bytes;
- stats->rx_packets = tx_packets;
- stats->rx_errs = tx_errs;
- stats->rx_drop = tx_drop;
- stats->tx_bytes = rx_bytes;
- stats->tx_packets = rx_packets;
- stats->tx_errs = rx_errs;
- stats->tx_drop = rx_drop;
- } else {
- stats->rx_bytes = rx_bytes;
- stats->rx_packets = rx_packets;
- stats->rx_errs = rx_errs;
- stats->rx_drop = rx_drop;
- stats->tx_bytes = tx_bytes;
- stats->tx_packets = tx_packets;
- stats->tx_errs = tx_errs;
- stats->tx_drop = tx_drop;
- }
-
- VIR_FORCE_FCLOSE(fp);
- return 0;
- }
- }
- VIR_FORCE_FCLOSE(fp);
-
- virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
- _("/proc/net/dev: Interface not found"));
- return -1;
+ return virNetDevGetProcNetdevStats(ifname, stats, swapped);
}
#elif defined(HAVE_GETIFADDRS) && defined(AF_LINK)
int
--
2.13.7
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