Re: [libvirt] [RFC] net-dhcp-leases: Query: Reg: Leases API Script

I tried writing the helper program, didn't send v5, since I have some doubts. The program works. Problems listed below. diff --git a/src/Makefile.am b/src/Makefile.am index 21b9caf..ef88132 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -825,6 +825,9 @@ STORAGE_HELPER_DISK_SOURCES = \ UTIL_IO_HELPER_SOURCES = \ util/iohelper.c +UTIL_IO_LEASES_SOURCES = \ + util/leaseshelper.c + # Network filters NWFILTER_DRIVER_SOURCES = \ nwfilter/nwfilter_driver.h nwfilter/nwfilter_driver.c \ @@ -2384,6 +2387,23 @@ libvirt_iohelper_CFLAGS = \ $(NULL) endif WITH_LIBVIRTD +if WITH_LIBVIRTD +libexec_PROGRAMS += libvirt_leaseshelper +libvirt_leaseshelper_SOURCES = $(UTIL_IO_LEASES_SOURCES) +libvirt_leaseshelper_LDFLAGS = \ + $(NULL) +libvirt_leaseshelper_LDADD = \ + libvirt_util.la \ + ../gnulib/lib/libgnu.la +if WITH_DTRACE_PROBES +libvirt_leaseshelper_LDADD += libvirt_probes.lo +endif WITH_DTRACE_PROBES + +libvirt_leaseshelper_CFLAGS = \ + $(PIE_CFLAGS) \ + $(NULL) +endif WITH_LIBVIRTD + if WITH_STORAGE_DISK if WITH_LIBVIRTD libexec_PROGRAMS += libvirt_parthelper diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 3ce3130..182a426 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -1058,6 +1058,8 @@ networkBuildDhcpDaemonCommandLine(virNetworkObjPtr network, cmd = virCommandNew(dnsmasqCapsGetBinaryPath(caps)); virCommandAddArgFormat(cmd, "--conf-file=%s", configfile); + virCommandAddArgFormat(cmd, "--dhcp-script=%s", "/home/Wani/libvirt/src/libvirt_leaseshelper"); + //virCommandAddArgFormat(cmd, "--dhcp-script=%s", "/var/lib/libvirt/dnsmasq/dhcp-script"); *cmdout = cmd; ret = 0; cleanup: /* * leasehelper.c: * * Copyright (C) 2013-2014 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. If not, see * <http://www.gnu.org/licenses/>;. * * Author: Nehal J Wani <nehaljw.kkd1(a)gmail.com&gt; * */ #include <config.h> #include <stdio.h> #include <stdlib.h> #include "virutil.h" #include "virfile.h" #include "virbuffer.h" #include "virstring.h" #include "virerror.h" #include "viralloc.h" /** * VIR_NETWORK_DHCP_LEASE_FIELDS: * * Macro providing the maximum number of fields in an entry in * the leases file */ #define VIR_NETWORK_DHCP_LEASE_FIELDS 7 /** * VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX: * * Macro providing the upper limit on the size of leases file */ #define VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX 2097152 /* * Use this when passing possibly-NULL strings to printf-a-likes. */ # define NULL_STR(s) ((s) ? (s) : "*") int main(int argc, char **argv) { /* Doesn't hurt to check */ if (argc < 4) return -1; const char *action = argv[1]; const char *interface = NULL_STR(getenv("DNSMASQ_INTERFACE")); const char *expirytime = NULL_STR(getenv("DNSMASQ_LEASE_EXPIRES")); const char *mac = argv[2]; const char *ip = argv[3]; const char *iaid = NULL_STR(getenv("DNSMASQ_IAID")); const char *hostname = NULL_STR(getenv("DNSMASQ_SUPPLIED_HOSTNAME")); const char *clientid = NULL_STR(getenv("DNSMASQ_CLIENT_ID")); const char *lease_file = "/var/lib/libvirt/dnsmasq/dnsmasq-ip-mac.status"; const char *leases_str = NULL; char *lease_entries = NULL; char *lease_entry = NULL; char **lease_fields = NULL; bool delete = false; bool add = false; int rv = -1; int lease_file_len = 0; virBuffer buf_new_lease = VIR_BUFFER_INITIALIZER; virBuffer buf_all_leases = VIR_BUFFER_INITIALIZER; FILE *fp = NULL; if (getenv("DNSMASQ_IAID")) { mac = NULL_STR(getenv("DNSMASQ_MAC")); clientid = argv[2]; } /* Make sure the file exists. If not, 'touch' it */ fp = fopen(lease_file, "a+"); fclose(fp); /* Read entire contents */ if ((lease_file_len = virFileReadAll(lease_file, VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX, &lease_entries)) < 0) { goto cleanup; } if (STREQ(action, "add") || STREQ(action, "old") || STREQ(action, "del")) { if (mac || STREQ(action, "del")) { /* Delete the corresponding lease */ delete = true; if (STREQ(action, "add") || STREQ(action, "old")) { add = true; /* Enter new lease */ virBufferAsprintf(&buf_new_lease, "%s %s %s %s %s %s %s\n", interface, expirytime, mac, iaid, ip, hostname, clientid); if (virBufferError(&buf_new_lease)) { virBufferFreeAndReset(&buf_new_lease); // virReportOOMError(); goto cleanup; } } } } lease_entry = lease_entries[0] == '\0' ? NULL : lease_entries; while (lease_entry) { int nfields = 0; char *eol = strchr(lease_entry, '\n'); *eol = '\0'; /* Split the lease line */ if (!(lease_fields = virStringSplit(lease_entry, " ", VIR_NETWORK_DHCP_LEASE_FIELDS))) goto cleanup; nfields = virStringListLength(lease_fields); /* Forward lease_entry to the next lease */ lease_entry = strchr(lease_entry, '\0'); if (lease_entry - lease_entries + 1 < lease_file_len) lease_entry++; else lease_entry = NULL; if (nfields != VIR_NETWORK_DHCP_LEASE_FIELDS) goto cleanup; if (delete && STREQ(lease_fields[4], ip)) continue; else { virBufferAsprintf(&buf_all_leases, "%s %s %s %s %s %s %s\n", lease_fields[0], lease_fields[1], lease_fields[2], lease_fields[3], lease_fields[4], lease_fields[5], lease_fields[6]); if (virBufferError(&buf_all_leases)) { virBufferFreeAndReset(&buf_all_leases); //virReportOOMError(); goto cleanup; } } } if (add) virBufferAsprintf(&buf_all_leases, "%s", virBufferContentAndReset(&buf_new_lease)); rv = 0; /* Write to file */ leases_str = virBufferContentAndReset(&buf_all_leases); if (!leases_str) leases_str = ""; if (virFileWriteStr(lease_file, leases_str, 0) < 0) rv = -1; cleanup: VIR_FREE(lease_file); VIR_FREE(lease_entries); if (lease_fields) virStringFreeList(lease_fields); return rv; } Q1. Does every file have to include "* Copyright (C) 2013-2014 Red Hat, Inc." in its copyright? (hacking.html doesn't mention in detail) Q2. I am not able to use virReportOOMError();. It keeps asking for VIR_FROM_THIS Q3. Currently, I have hard-coded the location of custom-leasefile: const char *lease_file = "/var/lib/libvirt/dnsmasq/dnsmasq-ip-mac.status"; If we don't hard-code the location of file, then the program will have to ask src/network/bridge_driver.c, which is not allowed, as it is private to the network driver. Now, we have two options, either we leave the above as only one file and add leases of all networks to it, or, have different files for each network. The only difficulty in option 1 is, when a network is destroyed, its corresponding leases will also have to be deleted in the custom lease file. If we go for option 2, and have different files for each network, how will the above program know, while custom lease file has to be updated? -- Nehal J Wani