sync: allow sync for non-superusers

by requiring
- Datastore.Backup permission for target datastore
- Remote.Read permission for source remote/datastore
- Datastore.Prune if vanished snapshots should be removed
- Datastore.Modify if another user should own the freshly synced
snapshots

reading a sync job entry only requires knowing about both the source
remote and the target datastore.

note that this does not affect the Authid used to authenticate with the
remote, which of course also needs permissions to access the source
datastore.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

src/api2/admin/sync.rs

@@ -1,12 +1,15 @@
-use anyhow::{format_err, Error};
+use anyhow::{bail, format_err, Error};
 use serde_json::Value;
 
-use proxmox::api::{api, ApiMethod, Router, RpcEnvironment};
+use proxmox::api::{api, ApiMethod, Permission, Router, RpcEnvironment};
 use proxmox::api::router::SubdirMap;
 use proxmox::{list_subdirs_api_method, sortable};
 
 use crate::api2::types::*;
 use crate::api2::pull::do_sync_job;
+use crate::api2::config::sync::{check_sync_job_modify_access, check_sync_job_read_access};
+
+use crate::config::cached_user_info::CachedUserInfo;
 use crate::config::sync::{self, SyncJobStatus, SyncJobConfig};
 use crate::server::UPID;
 use crate::server::jobstate::{Job, JobState};
@@ -27,6 +30,10 @@ use crate::tools::systemd::time::{
         type: Array,
         items: { type: sync::SyncJobStatus },
     },
+    access: {
+        description: "Limited to sync jobs where user has Datastore.Audit on target datastore, and Remote.Audit on source remote.",
+        permission: &Permission::Anybody,
+    },
 )]
 /// List all sync jobs
 pub fn list_sync_jobs(
@@ -35,6 +42,9 @@ pub fn list_sync_jobs(
     mut rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<Vec<SyncJobStatus>, Error> {
 
+    let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
+    let user_info = CachedUserInfo::new()?;
+
     let (config, digest) = sync::config()?;
 
     let mut list: Vec<SyncJobStatus> = config
@@ -46,6 +56,10 @@ pub fn list_sync_jobs(
             } else {
                 true
             }
+        })
+        .filter(|job: &SyncJobStatus| {
+            let as_config: SyncJobConfig = job.clone().into();
+            check_sync_job_read_access(&user_info, &auth_id, &as_config)
         }).collect();
 
     for job in &mut list {
@@ -89,7 +103,11 @@ pub fn list_sync_jobs(
                 schema: JOB_ID_SCHEMA,
             }
         }
-    }
+    },
+    access: {
+        description: "User needs Datastore.Backup on target datastore, and Remote.Read on source remote. Additionally, remove_vanished requires Datastore.Prune, and any owner other than the user themselves requires Datastore.Modify",
+        permission: &Permission::Anybody,
+    },
 )]
 /// Runs the sync jobs manually.
 fn run_sync_job(
@@ -97,11 +115,15 @@ fn run_sync_job(
     _info: &ApiMethod,
     rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<String, Error> {
+    let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
+    let user_info = CachedUserInfo::new()?;
 
     let (config, _digest) = sync::config()?;
     let sync_job: SyncJobConfig = config.lookup("sync", &id)?;
 
-    let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
+    if !check_sync_job_modify_access(&user_info, &auth_id, &sync_job) {
+        bail!("permission check failed");
+    }
 
     let job = Job::new("syncjob", &id)?;