pbs-config: use new SharedMemory helpers from proxmox-shared-memory crate

depend on proxmox-shared-memory crate.

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>

debian/control

@@ -62,6 +62,7 @@ Build-Depends: debhelper (>= 12),
  librust-proxmox-schema-1+default-dev,
  librust-proxmox-schema-1+upid-api-impl-dev,
  librust-proxmox-section-config-1+default-dev,
+ librust-proxmox-shared-memory-dev,
  librust-proxmox-tfa-1+default-dev,
  librust-proxmox-tfa-1+u2f-dev,
  librust-proxmox-time-1+default-dev,

pbs-config/Cargo.toml

@@ -23,6 +23,7 @@ proxmox-router = { version = "1.1", default-features = false }
 proxmox-schema = "1"
 proxmox-section-config = "1"
 proxmox-time = "1"
+proxmox-shared-memory = "0.1.0"
 
 pbs-api-types = { path = "../pbs-api-types" }
 pbs-buildcfg = { path = "../pbs-buildcfg" }

pbs-config/src/cached_user_info.rs

@@ -12,7 +12,7 @@ use proxmox_time::epoch_i64;
 use pbs_api_types::{Authid, Userid, User, ApiToken, ROLE_ADMIN};
 
 use crate::acl::{AclTree, ROLE_NAMES};
-use crate::memcom::Memcom;
+use crate::ConfigVersionCache;
 
 /// Cache User/Group/Token/Acl configuration data for fast permission tests
 pub struct CachedUserInfo {
@@ -38,8 +38,8 @@ impl CachedUserInfo {
     pub fn new() -> Result<Arc<Self>, Error> {
         let now = epoch_i64();
 
-        let memcom = Memcom::new()?;
+        let version_cache = ConfigVersionCache::new()?;
-        let user_cache_generation = memcom.user_cache_generation();
+        let user_cache_generation = version_cache.user_cache_generation();
 
         { // limit scope
             let cache = CACHED_CONFIG.read().unwrap();

pbs-config/src/config_version_cache.rs

@@ -0,0 +1,121 @@
+use std::path::Path;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::mem::MaybeUninit;
+
+use anyhow::{bail, Error};
+use once_cell::sync::OnceCell;
+use nix::sys::stat::Mode;
+
+use proxmox::tools::fs::{create_path, CreateOptions};
+
+// openssl::sha::sha256(b"Proxmox Backup ConfigVersionCache v1.0")[0..8];
+pub const PROXMOX_BACKUP_CONFIG_VERSION_CACHE_MAGIC_1_0: [u8; 8] = [25, 198, 168, 230, 154, 132, 143, 131];
+
+const FILE_PATH: &str = pbs_buildcfg::rundir!("/shmem/config-versions");
+
+use proxmox_shared_memory::*;
+
+#[derive(Debug)]
+#[repr(C)]
+struct ConfigVersionCacheData {
+    magic: [u8; 8],
+    // User (user.cfg) cache generation/version.
+    user_cache_generation: AtomicUsize,
+    // Traffic control (traffic-control.cfg) generation/version.
+    traffic_control_generation: AtomicUsize,
+
+    // Add further atomics here (and reduce padding size)
+
+    padding: [u8; 4096 - 3*8],
+}
+
+
+impl Init for ConfigVersionCacheData {
+    fn initialize(this: &mut MaybeUninit<Self>) {
+        unsafe {
+            let me = &mut *this.as_mut_ptr();
+            me.magic = PROXMOX_BACKUP_CONFIG_VERSION_CACHE_MAGIC_1_0;
+        }
+    }
+
+    fn check_type_magic(this: &MaybeUninit<Self>) -> Result<(), Error> {
+        unsafe {
+            let me = &*this.as_ptr();
+            if me.magic != PROXMOX_BACKUP_CONFIG_VERSION_CACHE_MAGIC_1_0 {
+                bail!("ConfigVersionCache: wrong magic number");
+            }
+            Ok(())
+        }
+    }
+}
+
+
+pub struct ConfigVersionCache {
+    shmem: SharedMemory<ConfigVersionCacheData>
+}
+
+static INSTANCE: OnceCell<Arc< ConfigVersionCache>> = OnceCell::new();
+
+impl ConfigVersionCache {
+
+    /// Open the memory based communication channel singleton.
+    pub fn new() -> Result<Arc<Self>, Error> {
+        INSTANCE.get_or_try_init(Self::open).map(Arc::clone)
+    }
+
+    // Actual work of `new`:
+    fn open() -> Result<Arc<Self>, Error> {
+        let user = crate::backup_user()?;
+
+        let dir_opts = CreateOptions::new()
+            .perm(Mode::from_bits_truncate(0o770))
+            .owner(user.uid)
+            .group(user.gid);
+
+        let file_path = Path::new(FILE_PATH);
+        let dir_path = file_path.parent().unwrap();
+        
+        create_path(
+            dir_path,
+            Some(dir_opts.clone()),
+            Some(dir_opts))?;
+
+        let file_opts = CreateOptions::new()
+            .perm(Mode::from_bits_truncate(0o660))
+            .owner(user.uid)
+            .group(user.gid);
+
+        let shmem: SharedMemory<ConfigVersionCacheData> =
+            SharedMemory::open(file_path, file_opts)?;
+
+        Ok(Arc::new(Self { shmem }))
+    }
+
+    /// Returns the user cache generation number.
+    pub fn user_cache_generation(&self) -> usize {
+        self.shmem.data()
+            .user_cache_generation.load(Ordering::Acquire)
+    }
+
+    /// Increase the user cache generation number.
+    pub fn increase_user_cache_generation(&self) {
+        self.shmem.data()
+            .user_cache_generation
+            .fetch_add(1, Ordering::AcqRel);
+    }
+
+    /// Returns the traffic control generation number.
+    pub fn traffic_control_generation(&self) -> usize {
+        self.shmem.data()
+            .traffic_control_generation.load(Ordering::Acquire)
+    }
+
+    /// Increase the traffic control generation number.
+    pub fn increase_traffic_control_generation(&self) {
+        self.shmem.data()
+            .traffic_control_generation
+            .fetch_add(1, Ordering::AcqRel);
+    }
+
+}

pbs-config/src/lib.rs

@@ -16,7 +16,8 @@ pub mod traffic_control;
 pub mod user;
 pub mod verify;
 
-pub mod memcom;
+mod config_version_cache;
+pub use config_version_cache::ConfigVersionCache;
 
 use anyhow::{format_err, Error};
 

pbs-config/src/memcom.rs

@@ -1,98 +0,0 @@
-//! Memory based communication channel between proxy & daemon for things such as cache
-//! invalidation.
-
-use std::os::unix::io::AsRawFd;
-use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::Arc;
-
-use anyhow::Error;
-use nix::fcntl::OFlag;
-use nix::sys::mman::{MapFlags, ProtFlags};
-use nix::sys::stat::Mode;
-use once_cell::sync::OnceCell;
-
-use proxmox::tools::fs::CreateOptions;
-use proxmox::tools::mmap::Mmap;
-
-/// In-memory communication channel.
-pub struct Memcom {
-    mmap: Mmap<u8>,
-}
-
-#[repr(C)]
-struct Head {
-    // User (user.cfg) cache generation/version.
-    user_cache_generation: AtomicUsize,
-    // Traffic control (traffic-control.cfg) generation/version.
-    traffic_control_generation: AtomicUsize,
-}
-
-static INSTANCE: OnceCell<Arc<Memcom>> = OnceCell::new();
-
-const MEMCOM_FILE_PATH: &str = pbs_buildcfg::rundir!("/proxmox-backup-memcom");
-const EMPTY_PAGE: [u8; 4096] = [0u8; 4096];
-
-impl Memcom {
-    /// Open the memory based communication channel singleton.
-    pub fn new() -> Result<Arc<Self>, Error> {
-        INSTANCE.get_or_try_init(Self::open).map(Arc::clone)
-    }
-
-    // Actual work of `new`:
-    fn open() -> Result<Arc<Self>, Error> {
-        let user = crate::backup_user()?;
-        let options = CreateOptions::new()
-            .perm(Mode::from_bits_truncate(0o660))
-            .owner(user.uid)
-            .group(user.gid);
-
-        let file = proxmox::tools::fs::atomic_open_or_create_file(
-            MEMCOM_FILE_PATH,
-            OFlag::O_RDWR | OFlag::O_CLOEXEC,
-            &EMPTY_PAGE,
-            options,
-            true,
-        )?;
-
-        let mmap = unsafe {
-            Mmap::<u8>::map_fd(
-                file.as_raw_fd(),
-                0,
-                4096,
-                ProtFlags::PROT_READ | ProtFlags::PROT_WRITE,
-                MapFlags::MAP_SHARED | MapFlags::MAP_NORESERVE | MapFlags::MAP_POPULATE,
-            )?
-        };
-
-        Ok(Arc::new(Self { mmap }))
-    }
-
-    // Shortcut to get the mapped `Head` as a `Head`.
-    fn head(&self) -> &Head {
-        unsafe { &*(self.mmap.as_ptr() as *const u8 as *const Head) }
-    }
-
-    /// Returns the user cache generation number.
-    pub fn user_cache_generation(&self) -> usize {
-        self.head().user_cache_generation.load(Ordering::Acquire)
-    }
-
-    /// Increase the user cache generation number.
-    pub fn increase_user_cache_generation(&self) {
-        self.head()
-            .user_cache_generation
-            .fetch_add(1, Ordering::AcqRel);
-    }
-
-    /// Returns the traffic control generation number.
-    pub fn traffic_control_generation(&self) -> usize {
-        self.head().traffic_control_generation.load(Ordering::Acquire)
-    }
-
-    /// Increase the traffic control generation number.
-    pub fn increase_traffic_control_generation(&self) {
-        self.head()
-            .traffic_control_generation
-            .fetch_add(1, Ordering::AcqRel);
-    }
-}

pbs-config/src/traffic_control.rs

@@ -10,7 +10,7 @@ use pbs_api_types::{TrafficControlRule, TRAFFIC_CONTROL_ID_SCHEMA};
 
 use proxmox_section_config::{SectionConfig, SectionConfigData, SectionConfigPlugin};
 
-use crate::memcom::Memcom;
+use crate::ConfigVersionCache;
 use crate::{open_backup_lockfile, replace_backup_config, BackupLockGuard};
 
 lazy_static! {
@@ -57,10 +57,10 @@ pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(TRAFFIC_CONTROL_CFG_FILENAME, &config)?;
     replace_backup_config(TRAFFIC_CONTROL_CFG_FILENAME, raw.as_bytes())?;
 
-    // increase traffic control generation
+    // increase traffic control version
     // We use this in TrafficControlCache
-    let memcom = Memcom::new()?;
+    let version_cache = ConfigVersionCache::new()?;
-    memcom.increase_traffic_control_generation();
+    version_cache.increase_traffic_control_generation();
 
     Ok(())
 }

pbs-config/src/user.rs

@@ -11,7 +11,7 @@ use pbs_api_types::{
     Authid, Userid, ApiToken, User,
 };
 
-use crate::memcom::Memcom;
+use crate::ConfigVersionCache;
 
 use crate::{open_backup_lockfile, replace_backup_config, BackupLockGuard};
 
@@ -120,10 +120,10 @@ pub fn save_config(config: &SectionConfigData) -> Result<(), Error> {
     let raw = CONFIG.write(USER_CFG_FILENAME, &config)?;
     replace_backup_config(USER_CFG_FILENAME, raw.as_bytes())?;
 
-    // increase user cache generation
+    // increase user version
     // We use this in CachedUserInfo
-    let memcom = Memcom::new()?;
+    let version_cache = ConfigVersionCache::new()?;
-    memcom.increase_user_cache_generation();
+    version_cache.increase_user_cache_generation();
 
     Ok(())
 }

src/cached_traffic_control.rs

@@ -14,7 +14,7 @@ use proxmox_time::TmEditor;
 
 use pbs_api_types::TrafficControlRule;
 
-use pbs_config::memcom::Memcom;
+use pbs_config::ConfigVersionCache;
 
 struct ParsedTcRule {
     config: TrafficControlRule, // original rule config
@@ -97,15 +97,15 @@ impl TrafficControlCache {
     }
 
     pub fn reload(&mut self, now: i64) {
-        let memcom = match Memcom::new() {
+        let version_cache = match ConfigVersionCache::new() {
-            Ok(memcom) => memcom,
+            Ok(cache) => cache,
             Err(err) => {
-                log::error!("TrafficControlCache::reload failed in Memcom::new: {}", err);
+                log::error!("TrafficControlCache::reload failed in ConfigVersionCache::new: {}", err);
                 return;
             }
         };
 
-        let traffic_control_generation = memcom.traffic_control_generation();
+        let traffic_control_generation = version_cache.traffic_control_generation();
 
         if (self.last_update != 0) &&
             (traffic_control_generation == self.last_traffic_control_generation) &&