On Sun, Apr 30, 2023 at 11:19:23PM -0400, Laine Stump wrote:
> This is the only iptables-specific function in all of
> virfirewall.c. By moving it to viriptables.c (with appropriate
> renaming), and calling it indirectly through a similarly named wrapper
> function in virnetfilter.c, we have made virfirewall.c backend
> agnostic (the new wrapper function will soon be calling either
> virIptablesApplyFirewallRule() or (to-be-created)
> virNftablesApplyFirewallRule() depending on the backend chosen when
> creating the virFirewall object).
>
> Signed-off-by: Laine Stump <laine@xxxxxxxxxx>
> ---
> src/libvirt_private.syms | 2 ++
> src/util/virfirewall.c | 72 ++-----------------------------------
> src/util/viriptables.c | 78 ++++++++++++++++++++++++++++++++++++++++
> src/util/viriptables.h | 6 ++++
> src/util/virnetfilter.c | 19 ++++++++++
> src/util/virnetfilter.h | 3 ++
I don't much like this split of responsibilities.
With the current codebase
* virfirewall.c is the low level transactional interface for
interacting with firewalls.
* viriptables.c is a medium level interface providing helpers
needed by the network bridge driver
The viriptables.c file probably ought not to even be located
in the src/util directory. Its API is inherantly tied to the
bridge driver, so ought to be moved to src/network/bridge_iptables.c
I think.
IOW, we have a clean flow from high level to low level of
bridge_driver.c -> viriptables.c -> virfirewall.c
and
nwfilter_driver.c -> nwfilter_ebiptables_driver.c -> virfirewall.c
After this change, AFAICT we have dependancy loops
* virfirewall.c is the low level transactional interface for
interacting with firwalls
* viriptables.c is a medium level interface providing helpers
needed by the netfilter APIs, and also helpers needed by
virfirewall.c
* virnetfilter.c is a slightly higher level inteface
providing helpers needed by the bridge interface
IOW, AFAICT we now have
bridge-driver.c -> virnetfilter.c -> viriptables.c -> virfirewall.c
^ |
| |
\-----------------/
and
nwfilter_driver.c -> nwfilter_ebiptables_driver.c -> virfirewall.c -> viriptables.c
> 6 files changed, 110 insertions(+), 70 deletions(-)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 11b84a866a..cf68e4c942 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2550,6 +2550,7 @@ virInitctlSetRunLevel;
> iptablesAddOutputFixUdpChecksum;
> iptablesRemoveOutputFixUdpChecksum;
> iptablesSetupPrivateChains;
> +virIptablesApplyFirewallRule;
>
>
> # util/viriscsi.h
> @@ -2949,6 +2950,7 @@ virNetfilterAddTcpInput;
> virNetfilterAddTcpOutput;
> virNetfilterAddUdpInput;
> virNetfilterAddUdpOutput;
> +virNetfilterApplyFirewallRule;
> virNetfilterRemoveDontMasquerade;
> virNetfilterRemoveForwardAllowCross;
> virNetfilterRemoveForwardAllowIn;
> diff --git a/src/util/virfirewall.c b/src/util/virfirewall.c
> index e3ba8f7846..6603fd6341 100644
> --- a/src/util/virfirewall.c
> +++ b/src/util/virfirewall.c
> @@ -24,6 +24,7 @@
>
> #include "virfirewall.h"
> #include "virfirewalld.h"
> +#include "virnetfilter.h"
> #include "viralloc.h"
> #include "virerror.h"
> #include "vircommand.h"
> @@ -37,14 +38,6 @@ VIR_LOG_INIT("util.firewall");
>
> typedef struct _virFirewallGroup virFirewallGroup;
>
> -VIR_ENUM_DECL(virFirewallLayerCommand);
> -VIR_ENUM_IMPL(virFirewallLayerCommand,
> - VIR_FIREWALL_LAYER_LAST,
> - EBTABLES,
> - IPTABLES,
> - IP6TABLES,
> -);
> -
> struct _virFirewallRule {
> virFirewallLayer layer;
>
> @@ -500,67 +493,6 @@ virFirewallRuleToString(const char *cmd,
> }
>
>
> -static int
> -virFirewallApplyRuleDirect(virFirewallRule *rule,
> - char **output)
> -{
> - size_t i;
> - const char *bin = virFirewallLayerCommandTypeToString(rule->layer);
> - g_autoptr(virCommand) cmd = NULL;
> - g_autofree char *cmdStr = NULL;
> - int status;
> - g_autofree char *error = NULL;
> -
> - if (!bin) {
> - virReportError(VIR_ERR_INTERNAL_ERROR,
> - _("Unknown firewall layer %1$d"),
> - rule->layer);
> - return -1;
> - }
> -
> - cmd = virCommandNewArgList(bin, NULL);
> -
> - /* lock to assure nobody else is messing with the tables while we are */
> - switch (rule->layer) {
> - case VIR_FIREWALL_LAYER_ETHERNET:
> - virCommandAddArg(cmd, "--concurrent");
> - break;
> - case VIR_FIREWALL_LAYER_IPV4:
> - case VIR_FIREWALL_LAYER_IPV6:
> - virCommandAddArg(cmd, "-w");
> - break;
> - case VIR_FIREWALL_LAYER_LAST:
> - break;
> - }
> -
> - for (i = 0; i < rule->argsLen; i++)
> - virCommandAddArg(cmd, rule->args[i]);
> -
> - cmdStr = virCommandToString(cmd, false);
> - VIR_INFO("Applying rule '%s'", NULLSTR(cmdStr));
> -
> - virCommandSetOutputBuffer(cmd, output);
> - virCommandSetErrorBuffer(cmd, &error);
> -
> - if (virCommandRun(cmd, &status) < 0)
> - return -1;
> -
> - if (status != 0) {
> - if (virFirewallRuleGetIgnoreErrors(rule)) {
> - VIR_DEBUG("Ignoring error running command");
> - } else {
> - virReportError(VIR_ERR_INTERNAL_ERROR,
> - _("Failed to apply firewall rules %1$s: %2$s"),
> - NULLSTR(cmdStr), NULLSTR(error));
> - VIR_FREE(*output);
> - return -1;
> - }
> - }
> -
> - return 0;
> -}
> -
> -
> static int
> virFirewallApplyRule(virFirewall *firewall,
> virFirewallRule *rule)
> @@ -568,7 +500,7 @@ virFirewallApplyRule(virFirewall *firewall,
> g_autofree char *output = NULL;
> g_auto(GStrv) lines = NULL;
>
> - if (virFirewallApplyRuleDirect(rule, &output) < 0)
> + if (virNetfilterApplyFirewallRule(firewall, rule, &output) < 0)
> return -1;
>
> if (rule->queryCB && output) {
> diff --git a/src/util/viriptables.c b/src/util/viriptables.c
> index a0c35887c5..9c7f7790c4 100644
> --- a/src/util/viriptables.c
> +++ b/src/util/viriptables.c
> @@ -31,6 +31,8 @@
> #include "viriptables.h"
> #include "virfirewalld.h"
> #include "virerror.h"
> +#include "viralloc.h"
> +#include "vircommand.h"
> #include "virlog.h"
> #include "virhash.h"
> #include "virenum.h"
> @@ -40,6 +42,19 @@ VIR_LOG_INIT("util.iptables");
> #define VIR_FROM_THIS VIR_FROM_NONE
>
>
> +/* iptables backend uses a different program for each layer. This
> + * gives us a convenient function for converting VIR_FIREWALL_LAYER_*
> + * enum from a virFirewallRule into a binary name.
> + */
> +VIR_ENUM_DECL(virIptablesLayerCommand);
> +VIR_ENUM_IMPL(virIptablesLayerCommand,
> + VIR_FIREWALL_LAYER_LAST,
> + EBTABLES,
> + IPTABLES,
> + IP6TABLES,
> +);
> +
> +
> VIR_ENUM_DECL(virIptablesAction);
> VIR_ENUM_IMPL(virIptablesAction,
> VIR_FIREWALL_ACTION_LAST,
> @@ -49,6 +64,69 @@ VIR_ENUM_IMPL(virIptablesAction,
> );
>
>
> +int
> +virIptablesApplyFirewallRule(virFirewall *firewall G_GNUC_UNUSED,
> + virFirewallRule *rule,
> + char **output)
> +{
> + virFirewallLayer layer = virFirewallRuleGetLayer(rule);
> + const char *bin = virIptablesLayerCommandTypeToString(layer);
> + g_autoptr(virCommand) cmd = NULL;
> + g_autofree char *cmdStr = NULL;
> + g_autofree char *error = NULL;
> + size_t i, count;
> + int status;
> +
> + if (!bin) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Unknown firewall layer %1$d"), layer);
> + return -1;
> + }
> +
> + cmd = virCommandNewArgList(bin, NULL);
> +
> + /* lock to assure nobody else is messing with the tables while we are */
> + switch (layer) {
> + case VIR_FIREWALL_LAYER_ETHERNET:
> + virCommandAddArg(cmd, "--concurrent");
> + break;
> + case VIR_FIREWALL_LAYER_IPV4:
> + case VIR_FIREWALL_LAYER_IPV6:
> + virCommandAddArg(cmd, "-w");
> + break;
> + case VIR_FIREWALL_LAYER_LAST:
> + break;
> + }
> +
> + count = virFirewallRuleGetArgCount(rule);
> + for (i = 0; i < count; i++)
> + virCommandAddArg(cmd, virFirewallRuleGetArg(rule, i));
> +
> + cmdStr = virCommandToString(cmd, false);
> + VIR_INFO("Applying rule '%s'", NULLSTR(cmdStr));
> +
> + virCommandSetOutputBuffer(cmd, output);
> + virCommandSetErrorBuffer(cmd, &error);
> +
> + if (virCommandRun(cmd, &status) < 0)
> + return -1;
> +
> + if (status != 0) {
> + if (virFirewallRuleGetIgnoreErrors(rule)) {
> + VIR_DEBUG("Ignoring error running command");
> + } else {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Failed to apply firewall rules %1$s: %2$s"),
> + NULLSTR(cmdStr), NULLSTR(error));
> + VIR_FREE(*output);
> + return -1;
> + }
> + }
> +
> + return 0;
> +}
> +
> +
> typedef struct {
> const char *parent;
> const char *child;
> diff --git a/src/util/viriptables.h b/src/util/viriptables.h
> index 17f43a8fa8..990cb2e25d 100644
> --- a/src/util/viriptables.h
> +++ b/src/util/viriptables.h
> @@ -24,6 +24,12 @@
> #include "virfirewall.h"
> #include "virnetfilter.h"
>
> +/* virIptablesApplyFirewallRule should be called only from virnetfilter.c */
> +int
> +virIptablesApplyFirewallRule(virFirewall *firewall,
> + virFirewallRule *rule,
> + char **output);
> +
> /* These functions are (currently) called directly from the consumer
> * (e.g. the network driver), and only when the iptables backend is
> * selected. (Possibly/probably functions should be added to the
> diff --git a/src/util/virnetfilter.c b/src/util/virnetfilter.c
> index 10c1a54e26..ba0f292ea9 100644
> --- a/src/util/virnetfilter.c
> +++ b/src/util/virnetfilter.c
> @@ -44,6 +44,25 @@ VIR_LOG_INIT("util.netfilter");
> #define VIR_FROM_THIS VIR_FROM_NONE
>
>
> +/**
> + * virNetfilterApplyFirewallRule:
> + * @fw: the virFirewall this rule is part of (currently unused)
> + * @rule: this particular rule
> + * @ignoreErrors: true if errors should be ignored
> + * @output: everything that appears on stdout as a result of applying the rule
> + *
> + * Applies @rule to the host's network filtering. returns 0 on success
> + * -1 on failure.
> + */
> +int
> +virNetfilterApplyFirewallRule(virFirewall *fw,
> + virFirewallRule *rule,
> + char **output)
> +{
> + return virIptablesApplyFirewallRule(fw, rule, output);
> +}
> +
> +
> /**
> * virNetfilterAddTcpInput:
> * @ctx: pointer to the IP table context
> diff --git a/src/util/virnetfilter.h b/src/util/virnetfilter.h
> index b515512ad7..eff047cde0 100644
> --- a/src/util/virnetfilter.h
> +++ b/src/util/virnetfilter.h
> @@ -30,6 +30,9 @@
> #define VIR_NETFILTER_FWD_X_CHAIN "LIBVIRT_FWX"
> #define VIR_NETFILTER_NAT_POSTROUTE_CHAIN "LIBVIRT_PRT"
>
> +int virNetfilterApplyFirewallRule (virFirewall *fw,
> + virFirewallRule *rule,
> + char **output);
> void virNetfilterAddTcpInput (virFirewall *fw,
> virFirewallLayer layer,
> const char *iface,
> --
> 2.39.2
>
With regards,
Daniel
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