[Devel] [PATCH] net: add support for "net/core/*" sysctls

[Pavel Tikhomirov]

One more thing, we likely need a test for it to zdtm, something like 
test/zdtm/static/netns-dev.c

On 4/17/19 11:40 AM, Pavel Tikhomirov wrote:
> Looks good to me except for a small naming confusion, e.g. ipv6_conf_op
> was named for "/proc/sys/net/ipv6/conf/" path to it, but in
> "/proc/sys/net/core" we don't have any conf, though we have coreconfs,
> core_conf_op, also arrays rconf and conf, and image field core_conf =).
> Think we can leave as is.
> 
> Reviewed-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
> 
> On 4/16/19 1:22 PM, Jan Dakinevich wrote:
>>    - handle 'somaxconn' option.
>>
>> https://jira.sw.ru/browse/PSBM-91415
>> Signed-off-by: Jan Dakinevich <jan.dakinevich at virtuozzo.com>
>> ---
>>    criu/net.c          | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>>    images/netdev.proto |  2 ++
>>    2 files changed, 81 insertions(+), 1 deletion(-)
>>
>> diff --git a/criu/net.c b/criu/net.c
>> index 3eebf48..6aa8bc6 100644
>> --- a/criu/net.c
>> +++ b/criu/net.c
>> @@ -334,6 +334,61 @@ static int ipv6_conf_op(char *tgt, SysctlEntry **conf, int n, int op, SysctlEntr
>>    			devconfs6, def_conf);
>>    }
>>    
>> +static char *coreconfs[] = {
>> +	"somaxconn",
>> +};
>> +
>> +static int core_conf_op(SysctlEntry **conf, int n, int op)
>> +{
>> +	struct sysctl_req req[ARRAY_SIZE(coreconfs)];
>> +	char path[ARRAY_SIZE(coreconfs)][256];
>> +	SysctlEntry *rconf[ARRAY_SIZE(coreconfs)];
>> +	int ret = 0;
>> +	int i, ri;
>> +
>> +	if (n > ARRAY_SIZE(coreconfs))
>> +		pr_warn("The image contains unknown sysctl-s\n");
>> +
>> +	for (i = 0, ri = 0; i < ARRAY_SIZE(coreconfs); i++) {
>> +		if (i >= n) {
>> +			pr_warn("Skip %s\n", coreconfs[i]);
>> +			continue;
>> +		}
>> +
>> +		if (conf[i]->type != SYSCTL_TYPE__CTL_32)
>> +			continue;
>> +		if (op == CTL_WRITE && !conf[i]->has_iarg)
>> +			continue;
>> +
>> +		snprintf(path[i], sizeof(path[i]), "net/core/%s", coreconfs[i]);
>> +		req[ri].name = path[i];
>> +		req[ri].type = CTL_32;
>> +		req[ri].arg = &conf[i]->iarg;
>> +		if (op == CTL_READ || opts.weak_sysctls)
>> +			req[ri].flags = CTL_FLAGS_OPTIONAL;
>> +		else
>> +			req[ri].flags = 0;
>> +
>> +		rconf[ri] = conf[i];
>> +		ri++;
>> +	}
>> +
>> +	ret = sysctl_op(req, ri, op, CLONE_NEWNET);
>> +	if (ret < 0) {
>> +		pr_err("Failed to %s\n", (op == CTL_READ ? "read" : "write"));
>> +		return ret;
>> +	}
>> +
>> +	if (op == CTL_READ) {
>> +		for (i = 0; i < ri; i++) {
>> +			if (req[i].flags & CTL_FLAGS_HAS)
>> +				rconf[i]->has_iarg = true;
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>    /*
>>     * I case if some entry is missing in
>>     * the kernel, simply write DEVCONFS_UNUSED
>> @@ -1827,6 +1882,8 @@ static int dump_netns_conf(struct ns_id *ns, struct cr_imgset *fds)
>>    	char all_stable_secret[MAX_STR_CONF_LEN + 1] = {};
>>    	NetnsId	*ids;
>>    	struct netns_id *p;
>> +	int core_size = ARRAY_SIZE(coreconfs);
>> +	SysctlEntry *core_confs = NULL;
>>    
>>    	i = 0;
>>    	list_for_each_entry(p, &ns->net.ids, node)
>> @@ -1835,7 +1892,8 @@ static int dump_netns_conf(struct ns_id *ns, struct cr_imgset *fds)
>>    	o_buf = buf = xmalloc(
>>    			i * (sizeof(NetnsId*) + sizeof(NetnsId)) +
>>    			size4 * (sizeof(SysctlEntry*) + sizeof(SysctlEntry)) * 2 +
>> -			size6 * (sizeof(SysctlEntry*) + sizeof(SysctlEntry)) * 2
>> +			size6 * (sizeof(SysctlEntry*) + sizeof(SysctlEntry)) * 2 +
>> +			core_size * (sizeof(SysctlEntry*) + sizeof(SysctlEntry))
>>    		     );
>>    	if (!buf)
>>    		goto out;
>> @@ -1891,6 +1949,16 @@ static int dump_netns_conf(struct ns_id *ns, struct cr_imgset *fds)
>>    		}
>>    	}
>>    
>> +	netns.n_core_conf = core_size;
>> +	netns.core_conf = xptr_pull_s(&buf, core_size * sizeof(SysctlEntry*));
>> +	core_confs = xptr_pull_s(&buf, core_size * sizeof(SysctlEntry));
>> +
>> +	for (i = 0; i < core_size; i++) {
>> +		sysctl_entry__init(&core_confs[i]);
>> +		netns.core_conf[i] = &core_confs[i];
>> +		netns.core_conf[i]->type = CTL_32;
>> +	}
>> +
>>    	ret = ipv4_conf_op("default", netns.def_conf4, size4, CTL_READ, NULL);
>>    	if (ret < 0)
>>    		goto err_free;
>> @@ -1905,6 +1973,10 @@ static int dump_netns_conf(struct ns_id *ns, struct cr_imgset *fds)
>>    	if (ret < 0)
>>    		goto err_free;
>>    
>> +	ret = core_conf_op(netns.core_conf, core_size, CTL_READ);
>> +	if (ret < 0)
>> +		goto err_free;
>> +
>>    	ret = pb_write_one(img_from_set(fds, CR_FD_NETNS), &netns, PB_NETNS);
>>    err_free:
>>    	xfree(o_buf);
>> @@ -2114,6 +2186,12 @@ static int restore_netns_conf(struct ns_id *ns)
>>    		ret = ipv6_conf_op("default", (netns)->def_conf6, (netns)->n_def_conf6, CTL_WRITE, NULL);
>>    	}
>>    
>> +	if ((netns)->core_conf) {
>> +		ret = core_conf_op((netns)->core_conf, (netns)->n_core_conf, CTL_WRITE);
>> +		if (ret)
>> +			goto out;
>> +	}
>> +
>>    	ns->net.netns = netns;
>>    out:
>>    	return ret;
>> diff --git a/images/netdev.proto b/images/netdev.proto
>> index 476a92c..7b9ab8d 100644
>> --- a/images/netdev.proto
>> +++ b/images/netdev.proto
>> @@ -71,4 +71,6 @@ message netns_entry {
>>    
>>    	repeated netns_id nsids		= 7;
>>    	optional string	ext_key		= 8;
>> +
>> +	repeated sysctl_entry core_conf	= 9;
>>    }
>>
> 

-- 
Best regards, Tikhomirov Pavel
Software Developer, Virtuozzo.