linux: move libnl code into separate file

Move all the code using libnl functionality into a separate file to ease
modifications.

No functional change.

5 files changed, 153 insertions, 113 deletions

diff --git a/Makefile.am b/Makefile.am
index 0d95e370..ca2f90ba 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -214,6 +214,11 @@ linux_platform_sources = \
 	zfs/ZfsArcMeter.c \
 	zfs/ZfsCompressedArcMeter.c
 
+if HAVE_DELAYACCT
+linux_platform_headers += linux/LibNl.h
+linux_platform_sources += linux/LibNl.c
+endif
+
 if HTOP_LINUX
 AM_LDFLAGS += -rdynamic
 myhtopplatheaders = $(linux_platform_headers)
diff --git a/configure.ac b/configure.ac
index 8c9e484a..b3137dec 100644
--- a/configure.ac
+++ b/configure.ac
@@ -692,6 +692,7 @@ case "$enable_delayacct" in
       AC_MSG_ERROR([bad value '$enable_delayacct' for --enable-delayacct])
       ;;
 esac
+AM_CONDITIONAL([HAVE_DELAYACCT], [test "$enable_delayacct" = yes])
 
 
 AC_ARG_ENABLE([sensors],
diff --git a/linux/LibNl.c b/linux/LibNl.c
new file mode 100644
index 00000000..e61b14f6
--- /dev/null
+++ b/linux/LibNl.c
@@ -0,0 +1,123 @@
+/*
+htop - linux/LibNl.c
+(C) 2024 htop dev team
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "config.h" // IWYU pragma: keep
+
+#ifndef HAVE_DELAYACCT
+#error Compiling this file requires HAVE_DELAYACCT
+#endif
+
+#include "linux/LibNl.h"
+
+#include <linux/netlink.h>
+#include <linux/taskstats.h>
+
+#include <netlink/attr.h>
+#include <netlink/handlers.h>
+#include <netlink/msg.h>
+#include <netlink/netlink.h>
+#include <netlink/socket.h>
+#include <netlink/genl/genl.h>
+#include <netlink/genl/ctrl.h>
+
+
+static void initNetlinkSocket(LinuxProcessTable* this) {
+   this->netlink_socket = nl_socket_alloc();
+   if (this->netlink_socket == NULL) {
+      return;
+   }
+   if (nl_connect(this->netlink_socket, NETLINK_GENERIC) < 0) {
+      return;
+   }
+   this->netlink_family = genl_ctrl_resolve(this->netlink_socket, TASKSTATS_GENL_NAME);
+}
+
+void LibNl_destroyNetlinkSocket(LinuxProcessTable* this) {
+   if (!this->netlink_socket)
+      return;
+
+   nl_close(this->netlink_socket);
+   nl_socket_free(this->netlink_socket);
+   this->netlink_socket = NULL;
+}
+
+static int handleNetlinkMsg(struct nl_msg* nlmsg, void* linuxProcess) {
+   struct nlmsghdr* nlhdr;
+   struct nlattr* nlattrs[TASKSTATS_TYPE_MAX + 1];
+   const struct nlattr* nlattr;
+   struct taskstats stats;
+   int rem;
+   LinuxProcess* lp = (LinuxProcess*) linuxProcess;
+
+   nlhdr = nlmsg_hdr(nlmsg);
+
+   if (genlmsg_parse(nlhdr, 0, nlattrs, TASKSTATS_TYPE_MAX, NULL) < 0) {
+      return NL_SKIP;
+   }
+
+   if ((nlattr = nlattrs[TASKSTATS_TYPE_AGGR_PID]) || (nlattr = nlattrs[TASKSTATS_TYPE_NULL])) {
+      memcpy(&stats, nla_data(nla_next(nla_data(nlattr), &rem)), sizeof(stats));
+      assert(Process_getPid(&lp->super) == (pid_t)stats.ac_pid);
+
+      // The xxx_delay_total values wrap around on overflow.
+      // (Linux Kernel "Documentation/accounting/taskstats-struct.rst")
+      unsigned long long int timeDelta = stats.ac_etime * 1000 - lp->delay_read_time;
+      #define DELTAPERC(x, y) (timeDelta ? MINIMUM((float)((x) - (y)) / timeDelta * 100.0f, 100.0f) : NAN)
+      lp->cpu_delay_percent = DELTAPERC(stats.cpu_delay_total, lp->cpu_delay_total);
+      lp->blkio_delay_percent = DELTAPERC(stats.blkio_delay_total, lp->blkio_delay_total);
+      lp->swapin_delay_percent = DELTAPERC(stats.swapin_delay_total, lp->swapin_delay_total);
+      #undef DELTAPERC
+
+      lp->swapin_delay_total = stats.swapin_delay_total;
+      lp->blkio_delay_total = stats.blkio_delay_total;
+      lp->cpu_delay_total = stats.cpu_delay_total;
+      lp->delay_read_time = stats.ac_etime * 1000;
+   }
+   return NL_OK;
+}
+
+void LibNl_readDelayAcctData(LinuxProcessTable* this, LinuxProcess* process) {
+   struct nl_msg* msg;
+
+   if (!this->netlink_socket) {
+      initNetlinkSocket(this);
+      if (!this->netlink_socket) {
+         goto delayacct_failure;
+      }
+   }
+
+   if (nl_socket_modify_cb(this->netlink_socket, NL_CB_VALID, NL_CB_CUSTOM, handleNetlinkMsg, process) < 0) {
+      goto delayacct_failure;
+   }
+
+   if (! (msg = nlmsg_alloc())) {
+      goto delayacct_failure;
+   }
+
+   if (! genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, this->netlink_family, 0, NLM_F_REQUEST, TASKSTATS_CMD_GET, TASKSTATS_VERSION)) {
+      nlmsg_free(msg);
+   }
+
+   if (nla_put_u32(msg, TASKSTATS_CMD_ATTR_PID, Process_getPid(&process->super)) < 0) {
+      nlmsg_free(msg);
+   }
+
+   if (nl_send_sync(this->netlink_socket, msg) < 0) {
+      goto delayacct_failure;
+   }
+
+   if (nl_recvmsgs_default(this->netlink_socket) < 0) {
+      goto delayacct_failure;
+   }
+
+   return;
+
+delayacct_failure:
+   process->swapin_delay_percent = NAN;
+   process->blkio_delay_percent = NAN;
+   process->cpu_delay_percent = NAN;
+}
diff --git a/linux/LibNl.h b/linux/LibNl.h
new file mode 100644
index 00000000..e89c3694
--- /dev/null
+++ b/linux/LibNl.h
@@ -0,0 +1,18 @@
+#ifndef HEADER_LibNl
+#define HEADER_LibNl
+/*
+htop - linux/LibNl.h
+(C) 2024 htop dev team
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "linux/LinuxProcess.h"
+#include "linux/LinuxProcessTable.h"
+
+
+void LibNl_destroyNetlinkSocket(LinuxProcessTable* this);
+
+void LibNl_readDelayAcctData(LinuxProcessTable* this, LinuxProcess* process);
+
+#endif /* HEADER_LibNl */
diff --git a/linux/LinuxProcessTable.c b/linux/LinuxProcessTable.c
index 428199d2..9a5ffdb4 100644
--- a/linux/LinuxProcessTable.c
+++ b/linux/LinuxProcessTable.c
@@ -23,18 +23,6 @@ in the source distribution for its full text.
 #include <unistd.h>
 #include <sys/stat.h>
 
-#ifdef HAVE_DELAYACCT
-#include <linux/netlink.h>
-#include <linux/taskstats.h>
-#include <netlink/attr.h>
-#include <netlink/handlers.h>
-#include <netlink/msg.h>
-#include <netlink/netlink.h>
-#include <netlink/socket.h>
-#include <netlink/genl/genl.h>
-#include <netlink/genl/ctrl.h>
-#endif
-
 #include "Compat.h"
 #include "Hashtable.h"
 #include "Machine.h"
@@ -55,6 +43,10 @@ in the source distribution for its full text.
 #include "linux/LinuxProcess.h"
 #include "linux/Platform.h" // needed for GNU/hurd to get PATH_MAX  // IWYU pragma: keep
 
+#ifdef HAVE_DELAYACCT
+#include "linux/LibNl.h"
+#endif
+
 #if defined(MAJOR_IN_MKDEV)
 #include <sys/mkdev.h>
 #elif defined(MAJOR_IN_SYSMACROS)
@@ -187,21 +179,6 @@ static void LinuxProcessTable_initTtyDrivers(LinuxProcessTable* this) {
    this->ttyDrivers = ttyDrivers;
 }
 
-#ifdef HAVE_DELAYACCT
-
-static void LinuxProcessTable_initNetlinkSocket(LinuxProcessTable* this) {
-   this->netlink_socket = nl_socket_alloc();
-   if (this->netlink_socket == NULL) {
-      return;
-   }
-   if (nl_connect(this->netlink_socket, NETLINK_GENERIC) < 0) {
-      return;
-   }
-   this->netlink_family = genl_ctrl_resolve(this->netlink_socket, TASKSTATS_GENL_NAME);
-}
-
-#endif
-
 ProcessTable* ProcessTable_new(Machine* host, Hashtable* pidMatchList) {
    LinuxProcessTable* this = xCalloc(1, sizeof(LinuxProcessTable));
    Object_setClass(this, Class(ProcessTable));
@@ -227,10 +204,7 @@ void ProcessTable_delete(Object* cast) {
       free(this->ttyDrivers);
    }
    #ifdef HAVE_DELAYACCT
-   if (this->netlink_socket) {
-      nl_close(this->netlink_socket);
-      nl_socket_free(this->netlink_socket);
-   }
+   LibNl_destroyNetlinkSocket(this);
    #endif
    free(this);
 }
@@ -1010,87 +984,6 @@ static void LinuxProcessTable_readCwd(LinuxProcess* process, openat_arg_t procFd
    free_and_xStrdup(&process->super.procCwd, pathBuffer);
 }
 
-#ifdef HAVE_DELAYACCT
-
-static int handleNetlinkMsg(struct nl_msg* nlmsg, void* linuxProcess) {
-   struct nlmsghdr* nlhdr;
-   struct nlattr* nlattrs[TASKSTATS_TYPE_MAX + 1];
-   const struct nlattr* nlattr;
-   struct taskstats stats;
-   int rem;
-   LinuxProcess* lp = (LinuxProcess*) linuxProcess;
-
-   nlhdr = nlmsg_hdr(nlmsg);
-
-   if (genlmsg_parse(nlhdr, 0, nlattrs, TASKSTATS_TYPE_MAX, NULL) < 0) {
-      return NL_SKIP;
-   }
-
-   if ((nlattr = nlattrs[TASKSTATS_TYPE_AGGR_PID]) || (nlattr = nlattrs[TASKSTATS_TYPE_NULL])) {
-      memcpy(&stats, nla_data(nla_next(nla_data(nlattr), &rem)), sizeof(stats));
-      assert(Process_getPid(&lp->super) == (pid_t)stats.ac_pid);
-
-      // The xxx_delay_total values wrap around on overflow.
-      // (Linux Kernel "Documentation/accounting/taskstats-struct.rst")
-      unsigned long long int timeDelta = stats.ac_etime * 1000 - lp->delay_read_time;
-      #define DELTAPERC(x, y) (timeDelta ? MINIMUM((float)((x) - (y)) / timeDelta * 100.0f, 100.0f) : NAN)
-      lp->cpu_delay_percent = DELTAPERC(stats.cpu_delay_total, lp->cpu_delay_total);
-      lp->blkio_delay_percent = DELTAPERC(stats.blkio_delay_total, lp->blkio_delay_total);
-      lp->swapin_delay_percent = DELTAPERC(stats.swapin_delay_total, lp->swapin_delay_total);
-      #undef DELTAPERC
-
-      lp->swapin_delay_total = stats.swapin_delay_total;
-      lp->blkio_delay_total = stats.blkio_delay_total;
-      lp->cpu_delay_total = stats.cpu_delay_total;
-      lp->delay_read_time = stats.ac_etime * 1000;
-   }
-   return NL_OK;
-}
-
-static void LinuxProcessTable_readDelayAcctData(LinuxProcessTable* this, LinuxProcess* process) {
-   struct nl_msg* msg;
-
-   if (!this->netlink_socket) {
-      LinuxProcessTable_initNetlinkSocket(this);
-      if (!this->netlink_socket) {
-         goto delayacct_failure;
-      }
-   }
-
-   if (nl_socket_modify_cb(this->netlink_socket, NL_CB_VALID, NL_CB_CUSTOM, handleNetlinkMsg, process) < 0) {
-      goto delayacct_failure;
-   }
-
-   if (! (msg = nlmsg_alloc())) {
-      goto delayacct_failure;
-   }
-
-   if (! genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, this->netlink_family, 0, NLM_F_REQUEST, TASKSTATS_CMD_GET, TASKSTATS_VERSION)) {
-      nlmsg_free(msg);
-   }
-
-   if (nla_put_u32(msg, TASKSTATS_CMD_ATTR_PID, Process_getPid(&process->super)) < 0) {
-      nlmsg_free(msg);
-   }
-
-   if (nl_send_sync(this->netlink_socket, msg) < 0) {
-      goto delayacct_failure;
-   }
-
-   if (nl_recvmsgs_default(this->netlink_socket) < 0) {
-      goto delayacct_failure;
-   }
-
-   return;
-
-delayacct_failure:
-   process->swapin_delay_percent = NAN;
-   process->blkio_delay_percent = NAN;
-   process->cpu_delay_percent = NAN;
-}
-
-#endif
-
 static bool LinuxProcessTable_readCmdlineFile(Process* process, openat_arg_t procFd) {
    char filename[MAX_NAME + 1];
    ssize_t amtRead;
@@ -1593,7 +1486,7 @@ static bool LinuxProcessTable_recurseProcTree(LinuxProcessTable* this, openat_ar
 
       #ifdef HAVE_DELAYACCT
       if (ss->flags & PROCESS_FLAG_LINUX_DELAYACCT) {
-         LinuxProcessTable_readDelayAcctData(this, lp);
+         LibNl_readDelayAcctData(this, lp);
       }
       #endif