public inbox for pve-devel@lists.proxmox.com
 help / color / mirror / Atom feed
From: Stefan Hanreich <s.hanreich@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [pve-devel] [PATCH proxmox-firewall v2 3/3] fix #6336: fix ipfilter matching logic
Date: Thu, 25 Sep 2025 14:21:41 +0200	[thread overview]
Message-ID: <20250925122142.228719-5-s.hanreich@proxmox.com> (raw)
In-Reply-To: <20250925122142.228719-1-s.hanreich@proxmox.com>

Matching on ipsets in the firewall generally works by matching on two
sets (one for match, one for nomatch):

  ip saddr @ipfilter ip saddr != @ipfilter-nomatch <verdict>

Ipfilters were created with the comparison operators simply inverted,
which leads to ipfilters with empty nomatch sets never working, since
the second expression always evaluates to false on empty sets:

  ip saddr != @ipfilter ip saddr = @ipfilter-nomatch drop

In order to properly invert the logic, two statements need to be
generated (analogous to negation in boolean logic):

  ip saddr != @ipfilter drop
  ip saddr = @ipfilter-nomatch drop

To avoid cluttering the existing set handling function and to clearly
separate the rule generation logic, introduce a completely new
function that handles ipfilters separately. This also allows the set
handling function to validate the name of ipsets in a later commit,
since it only operates on ipsets that have to exist in the firewall
config, whereas ipfilters do not necessarily exist in the firewall
configuration.

Signed-off-by: Stefan Hanreich <s.hanreich@proxmox.com>
---
 proxmox-firewall/src/rule.rs                  | 131 ++++++++++++++++--
 .../integration_tests__firewall.snap          | 100 +++++++++++++
 2 files changed, 218 insertions(+), 13 deletions(-)

diff --git a/proxmox-firewall/src/rule.rs b/proxmox-firewall/src/rule.rs
index 2512537..23e87a5 100644
--- a/proxmox-firewall/src/rule.rs
+++ b/proxmox-firewall/src/rule.rs
@@ -283,12 +283,15 @@ impl ToNftRules for RuleMatch {
     }
 }
 
+/// Handle matching on an ipset.
+///
+/// This function adds statements to the `rules` that match on the ipset with the given name
+/// `name`. It matches the IPs contained in the ipset with the field given in `field_name`.
 fn handle_set(
     rules: &mut Vec<NftRule>,
     name: &IpsetName,
     field_name: &str,
     env: &NftRuleEnv,
-    contains: bool,
 ) -> Result<(), Error> {
     let mut new_rules = rules
         .drain(..)
@@ -303,7 +306,7 @@ fn handle_set(
 
                 rule.append(&mut vec![
                     Match::new(
-                        if contains { Operator::Eq } else { Operator::Ne },
+                        Operator::Eq,
                         field.clone(),
                         Expression::set_name(&SetName::ipset_name(
                             Family::V4,
@@ -314,7 +317,7 @@ fn handle_set(
                     )
                     .into(),
                     Match::new(
-                        if contains { Operator::Ne } else { Operator::Eq },
+                        Operator::Ne,
                         field,
                         Expression::set_name(&SetName::ipset_name(
                             Family::V4,
@@ -337,7 +340,7 @@ fn handle_set(
 
                 rule.append(&mut vec![
                     Match::new(
-                        if contains { Operator::Eq } else { Operator::Ne },
+                        Operator::Eq,
                         field.clone(),
                         Expression::set_name(&SetName::ipset_name(
                             Family::V6,
@@ -348,7 +351,7 @@ fn handle_set(
                     )
                     .into(),
                     Match::new(
-                        if contains { Operator::Ne } else { Operator::Eq },
+                        Operator::Ne,
                         field,
                         Expression::set_name(&SetName::ipset_name(
                             Family::V6,
@@ -372,6 +375,114 @@ fn handle_set(
     Ok(())
 }
 
+/// Handle matching on an ipfilter.
+///
+/// This function adds statements to the `rules` that match if the IP in the field `field_name`
+/// does not fulfill the criteria of the given ipfilter.
+fn handle_ipfilter(
+    rules: &mut Vec<NftRule>,
+    name: &IpsetName,
+    field_name: &str,
+    env: &NftRuleEnv,
+) -> Result<(), Error> {
+    let mut new_rules = rules
+        .drain(..)
+        .flat_map(|rule| {
+            let mut new_rules = Vec::new();
+
+            if matches!(rule.family(), Some(Family::V4) | None) && env.contains_family(Family::V4) {
+                let field = Payload::field("ip", field_name);
+
+                let mut match_rule = rule.clone();
+                match_rule.set_family(Family::V4);
+
+                match_rule.push(
+                    Match::new(
+                        Operator::Ne,
+                        field.clone(),
+                        Expression::set_name(&SetName::ipset_name(
+                            Family::V4,
+                            name,
+                            env.vmid,
+                            false,
+                        )),
+                    )
+                    .into(),
+                );
+
+                new_rules.push(match_rule);
+
+                let mut nomatch_rule = rule.clone();
+                nomatch_rule.set_family(Family::V4);
+
+                nomatch_rule.push(
+                    Match::new(
+                        Operator::Eq,
+                        field,
+                        Expression::set_name(&SetName::ipset_name(
+                            Family::V4,
+                            name,
+                            env.vmid,
+                            true,
+                        )),
+                    )
+                    .into(),
+                );
+
+                new_rules.push(nomatch_rule);
+            }
+
+            if matches!(rule.family(), Some(Family::V6) | None) && env.contains_family(Family::V6) {
+                let field = Payload::field("ip6", field_name);
+
+                let mut match_rule = rule.clone();
+                match_rule.set_family(Family::V4);
+
+                match_rule.push(
+                    Match::new(
+                        Operator::Ne,
+                        field.clone(),
+                        Expression::set_name(&SetName::ipset_name(
+                            Family::V6,
+                            name,
+                            env.vmid,
+                            false,
+                        )),
+                    )
+                    .into(),
+                );
+
+                new_rules.push(match_rule);
+
+                let mut nomatch_rule = rule.clone();
+                nomatch_rule.set_family(Family::V4);
+
+                nomatch_rule.push(
+                    Match::new(
+                        Operator::Eq,
+                        field,
+                        Expression::set_name(&SetName::ipset_name(
+                            Family::V6,
+                            name,
+                            env.vmid,
+                            true,
+                        )),
+                    )
+                    .into(),
+                );
+
+                new_rules.push(nomatch_rule);
+            }
+
+            new_rules
+        })
+        .collect::<Vec<NftRule>>();
+
+    rules.append(&mut new_rules);
+
+    Ok(())
+}
+
 fn handle_match(
     rules: &mut Vec<NftRule>,
     ip: &IpAddrMatch,
@@ -447,7 +558,7 @@ fn handle_match(
 
             Ok(())
         }
-        IpAddrMatch::Set(name) => handle_set(rules, name, field_name, env, true),
+        IpAddrMatch::Set(name) => handle_set(rules, name, field_name, env),
     }
 }
 
@@ -679,13 +790,7 @@ impl ToNftRules for Ipfilter<'_> {
                 );
 
                 let mut ipfilter_rules = vec![base_rule.clone()];
-                handle_set(
-                    &mut ipfilter_rules,
-                    self.ipset().name(),
-                    "saddr",
-                    env,
-                    false,
-                )?;
+                handle_ipfilter(&mut ipfilter_rules, self.ipset().name(), "saddr", env)?;
                 rules.append(&mut ipfilter_rules);
 
                 if env.contains_family(Family::V4) {
diff --git a/proxmox-firewall/tests/snapshots/integration_tests__firewall.snap b/proxmox-firewall/tests/snapshots/integration_tests__firewall.snap
index feeda5b..71285af 100644
--- a/proxmox-firewall/tests/snapshots/integration_tests__firewall.snap
+++ b/proxmox-firewall/tests/snapshots/integration_tests__firewall.snap
@@ -4279,6 +4279,31 @@ expression: "firewall.full_host_fw().expect(\"firewall can be generated\")"
                 "right": "@v4-guest-100/ipfilter-net1"
               }
             },
+            {
+              "drop": null
+            }
+          ]
+        }
+      }
+    },
+    {
+      "add": {
+        "rule": {
+          "family": "bridge",
+          "table": "proxmox-firewall-guests",
+          "chain": "guest-100-out",
+          "expr": [
+            {
+              "match": {
+                "op": "==",
+                "left": {
+                  "meta": {
+                    "key": "iifname"
+                  }
+                },
+                "right": "veth100i1"
+              }
+            },
             {
               "match": {
                 "op": "==",
@@ -4328,6 +4353,31 @@ expression: "firewall.full_host_fw().expect(\"firewall can be generated\")"
                 "right": "@v6-guest-100/ipfilter-net1"
               }
             },
+            {
+              "drop": null
+            }
+          ]
+        }
+      }
+    },
+    {
+      "add": {
+        "rule": {
+          "family": "bridge",
+          "table": "proxmox-firewall-guests",
+          "chain": "guest-100-out",
+          "expr": [
+            {
+              "match": {
+                "op": "==",
+                "left": {
+                  "meta": {
+                    "key": "iifname"
+                  }
+                },
+                "right": "veth100i1"
+              }
+            },
             {
               "match": {
                 "op": "==",
@@ -4579,6 +4629,31 @@ expression: "firewall.full_host_fw().expect(\"firewall can be generated\")"
                 "right": "@v4-guest-100/ipfilter-net3"
               }
             },
+            {
+              "drop": null
+            }
+          ]
+        }
+      }
+    },
+    {
+      "add": {
+        "rule": {
+          "family": "bridge",
+          "table": "proxmox-firewall-guests",
+          "chain": "guest-100-out",
+          "expr": [
+            {
+              "match": {
+                "op": "==",
+                "left": {
+                  "meta": {
+                    "key": "iifname"
+                  }
+                },
+                "right": "veth100i3"
+              }
+            },
             {
               "match": {
                 "op": "==",
@@ -4628,6 +4703,31 @@ expression: "firewall.full_host_fw().expect(\"firewall can be generated\")"
                 "right": "@v6-guest-100/ipfilter-net3"
               }
             },
+            {
+              "drop": null
+            }
+          ]
+        }
+      }
+    },
+    {
+      "add": {
+        "rule": {
+          "family": "bridge",
+          "table": "proxmox-firewall-guests",
+          "chain": "guest-100-out",
+          "expr": [
+            {
+              "match": {
+                "op": "==",
+                "left": {
+                  "meta": {
+                    "key": "iifname"
+                  }
+                },
+                "right": "veth100i3"
+              }
+            },
             {
               "match": {
                 "op": "==",
-- 
2.47.3


_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel


      parent reply	other threads:[~2025-09-25 12:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-25 12:21 [pve-devel] [PATCH proxmox{-ve-rs, -firewall} v2 0/4] Fix ipfilters in proxmox-firewall Stefan Hanreich
2025-09-25 12:21 ` [pve-devel] [PATCH proxmox-ve-rs v2 1/1] config: guest: store network devices in BTreeMap Stefan Hanreich
2025-09-25 12:21 ` [pve-devel] [PATCH proxmox-firewall v2 1/3] run rustfmt Stefan Hanreich
2025-09-25 12:21 ` [pve-devel] [PATCH proxmox-firewall v2 2/3] ipfilter: fix wrong entries for containers Stefan Hanreich
2025-09-25 12:21 ` Stefan Hanreich [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250925122142.228719-5-s.hanreich@proxmox.com \
    --to=s.hanreich@proxmox.com \
    --cc=pve-devel@lists.proxmox.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Service provided by Proxmox Server Solutions GmbH | Privacy | Legal