diff mbox series

[PATCHv8,03/15] net/lwip: implement dns cmd

Message ID 20230908135320.7066-4-maxim.uvarov@linaro.org
State Changes Requested
Delegated to: Ramon Fried
Headers show
Series net/lwip: add lwip library for the network stack | expand

Commit Message

Maxim Uvarov Sept. 8, 2023, 1:53 p.m. UTC
U-Boot recently got support for an alternative network stack using LWIP.
Replace dns command with the LWIP variant while keeping the output and
error messages identical.

Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
---
 include/net/lwip.h           | 19 +++++++++++
 net/lwip/Makefile            |  2 ++
 net/lwip/apps/dns/lwip-dns.c | 63 ++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+)
 create mode 100644 include/net/lwip.h
 create mode 100644 net/lwip/apps/dns/lwip-dns.c

Comments

Ilias Apalodimas Sept. 13, 2023, 5:56 a.m. UTC | #1
On Fri, Sep 08, 2023 at 07:53:08PM +0600, Maxim Uvarov wrote:
> U-Boot recently got support for an alternative network stack using LWIP.
> Replace dns command with the LWIP variant while keeping the output and
> error messages identical.
>
> Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
> ---
>  include/net/lwip.h           | 19 +++++++++++
>  net/lwip/Makefile            |  2 ++
>  net/lwip/apps/dns/lwip-dns.c | 63 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 84 insertions(+)
>  create mode 100644 include/net/lwip.h
>  create mode 100644 net/lwip/apps/dns/lwip-dns.c
>
> diff --git a/include/net/lwip.h b/include/net/lwip.h
> new file mode 100644
> index 0000000000..ab3db1a214
> --- /dev/null
> +++ b/include/net/lwip.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +int do_lwip_dns(struct cmd_tbl *cmdtp, int flag, int argc,
> +		char *const argv[]);
> +
> +/**
> + * ulwip_dns() - creates the DNS request to resolve a domain host name
> + *
> + * This function creates the DNS request to resolve a domain host name. Function
> + * can return immediately if previous request was cached or it might require
> + * entering the polling loop for a request to a remote server.
> + *
> + * @name:    dns name to resolve
> + * @varname: (optional) U-Boot variable name to store the result
> + * Returns: ERR_OK(0) for fetching entry from the cache
> + *          -EINPROGRESS success, can go to the polling loop
> + *          Other value < 0, if error
> + */
> +int ulwip_dns(char *name, char *varname);
> diff --git a/net/lwip/Makefile b/net/lwip/Makefile
> index 3fd5d34564..5d8d5527c6 100644
> --- a/net/lwip/Makefile
> +++ b/net/lwip/Makefile
> @@ -62,3 +62,5 @@ obj-$(CONFIG_NET) += lwip-external/src/netif/ethernet.o
>
>  obj-$(CONFIG_NET) += port/if.o
>  obj-$(CONFIG_NET) += port/sys-arch.o
> +
> +obj-y += apps/dns/lwip-dns.o
> diff --git a/net/lwip/apps/dns/lwip-dns.c b/net/lwip/apps/dns/lwip-dns.c
> new file mode 100644
> index 0000000000..b340302f2c
> --- /dev/null
> +++ b/net/lwip/apps/dns/lwip-dns.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * (C) Copyright 2023 Linaro Ltd. <maxim.uvarov@linaro.org>
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <console.h>
> +
> +#include <lwip/dns.h>
> +#include <lwip/ip_addr.h>
> +
> +#include <net/ulwip.h>
> +
> +static void dns_found_cb(const char *name, const ip_addr_t *ipaddr, void *callback_arg)
> +{
> +	char *varname = (char *)callback_arg;
> +	char *ipstr = ip4addr_ntoa(ipaddr);
> +
> +	if (varname)
> +		env_set(varname, ipstr);
> +	log_info("resolved %s to %s\n",  name, ipstr);
> +	ulwip_exit(0);
> +}
> +
> +int ulwip_dns(char *name, char *varname)
> +{
> +	int err;
> +	ip_addr_t ipaddr; /* not used */
> +	ip_addr_t dns1;
> +	ip_addr_t dns2;
> +	char *dnsenv = env_get("dnsip");
> +	char *dns2env = env_get("dnsip2");
> +
> +	if (!dnsenv && !dns2env) {
> +		log_err("nameserver is not set with dnsip and dnsip2 vars\n");
> +		return -ENOENT;
> +	}
> +
> +	if (!dnsenv)
> +		log_warning("dnsip var is not set\n");
> +	if (!dns2env)
> +		log_warning("dnsip2 var is not set\n");
> +
> +	dns_init();
> +
> +	if (ipaddr_aton(dnsenv, &dns1))
> +		dns_setserver(0, &dns1);
> +
> +	if (ipaddr_aton(dns2env, &dns2))
> +		dns_setserver(1, &dns2);

env_get will return NULL if any of these is not set.  Looking at
ipaddr_aton() of lwip that might lead to a NULL deref in ip_2_ip6()

> +
> +	err = dns_gethostbyname(name, &ipaddr, dns_found_cb, varname);
> +	if (err == ERR_OK)
> +		dns_found_cb(name, &ipaddr, varname);
> +
> +	/* convert lwIP ERR_INPROGRESS to U-Boot -EINPROGRESS */
> +	if (err == ERR_INPROGRESS)
> +		err = -EINPROGRESS;
> +
> +	return err;
> +}
> --
> 2.30.2
>
Simon Goldschmidt Sept. 13, 2023, 8:32 a.m. UTC | #2
On 13.09.2023 07:56, Ilias Apalodimas wrote:
> On Fri, Sep 08, 2023 at 07:53:08PM +0600, Maxim Uvarov wrote:
>> U-Boot recently got support for an alternative network stack using LWIP.
>> Replace dns command with the LWIP variant while keeping the output and
>> error messages identical.
>>
>> Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
>> ---
>>   include/net/lwip.h           | 19 +++++++++++
>>   net/lwip/Makefile            |  2 ++
>>   net/lwip/apps/dns/lwip-dns.c | 63 ++++++++++++++++++++++++++++++++++++
>>   3 files changed, 84 insertions(+)
>>   create mode 100644 include/net/lwip.h
>>   create mode 100644 net/lwip/apps/dns/lwip-dns.c
>>
>> diff --git a/include/net/lwip.h b/include/net/lwip.h
>> new file mode 100644
>> index 0000000000..ab3db1a214
>> --- /dev/null
>> +++ b/include/net/lwip.h
>> @@ -0,0 +1,19 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +
>> +int do_lwip_dns(struct cmd_tbl *cmdtp, int flag, int argc,
>> +		char *const argv[]);
>> +
>> +/**
>> + * ulwip_dns() - creates the DNS request to resolve a domain host name
>> + *
>> + * This function creates the DNS request to resolve a domain host name. Function
>> + * can return immediately if previous request was cached or it might require
>> + * entering the polling loop for a request to a remote server.
>> + *
>> + * @name:    dns name to resolve
>> + * @varname: (optional) U-Boot variable name to store the result
>> + * Returns: ERR_OK(0) for fetching entry from the cache
>> + *          -EINPROGRESS success, can go to the polling loop
>> + *          Other value < 0, if error
>> + */
>> +int ulwip_dns(char *name, char *varname);
>> diff --git a/net/lwip/Makefile b/net/lwip/Makefile
>> index 3fd5d34564..5d8d5527c6 100644
>> --- a/net/lwip/Makefile
>> +++ b/net/lwip/Makefile
>> @@ -62,3 +62,5 @@ obj-$(CONFIG_NET) += lwip-external/src/netif/ethernet.o
>>
>>   obj-$(CONFIG_NET) += port/if.o
>>   obj-$(CONFIG_NET) += port/sys-arch.o
>> +
>> +obj-y += apps/dns/lwip-dns.o
>> diff --git a/net/lwip/apps/dns/lwip-dns.c b/net/lwip/apps/dns/lwip-dns.c
>> new file mode 100644
>> index 0000000000..b340302f2c
>> --- /dev/null
>> +++ b/net/lwip/apps/dns/lwip-dns.c
>> @@ -0,0 +1,63 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +
>> +/*
>> + * (C) Copyright 2023 Linaro Ltd. <maxim.uvarov@linaro.org>
>> + */
>> +
>> +#include <common.h>
>> +#include <command.h>
>> +#include <console.h>
>> +
>> +#include <lwip/dns.h>
>> +#include <lwip/ip_addr.h>
>> +
>> +#include <net/ulwip.h>
>> +
>> +static void dns_found_cb(const char *name, const ip_addr_t *ipaddr, void *callback_arg)
>> +{
>> +	char *varname = (char *)callback_arg;
>> +	char *ipstr = ip4addr_ntoa(ipaddr);
>> +
>> +	if (varname)
>> +		env_set(varname, ipstr);
>> +	log_info("resolved %s to %s\n",  name, ipstr);
>> +	ulwip_exit(0);
>> +}
>> +
>> +int ulwip_dns(char *name, char *varname)
>> +{
>> +	int err;
>> +	ip_addr_t ipaddr; /* not used */
>> +	ip_addr_t dns1;
>> +	ip_addr_t dns2;
>> +	char *dnsenv = env_get("dnsip");
>> +	char *dns2env = env_get("dnsip2");
>> +
>> +	if (!dnsenv && !dns2env) {
>> +		log_err("nameserver is not set with dnsip and dnsip2 vars\n");
>> +		return -ENOENT;
>> +	}
>> +
>> +	if (!dnsenv)
>> +		log_warning("dnsip var is not set\n");
>> +	if (!dns2env)
>> +		log_warning("dnsip2 var is not set\n");
>> +
>> +	dns_init();
>> +
>> +	if (ipaddr_aton(dnsenv, &dns1))
>> +		dns_setserver(0, &dns1);
>> +
>> +	if (ipaddr_aton(dns2env, &dns2))
>> +		dns_setserver(1, &dns2);
>
> env_get will return NULL if any of these is not set.  Looking at
> ipaddr_aton() of lwip that might lead to a NULL deref in ip_2_ip6()

Looking at the NULL checks in ipaddr_aton(), you found a bug in lwIP.
I'd vote to leave the above code as is and rely on the bug being fixed
in lwIP before U-Boot enables IPv6 (this is only a bug in dual-stack
mode where IPv4 and IPv6 is enabled).

Regards,
Simon

>
>> +
>> +	err = dns_gethostbyname(name, &ipaddr, dns_found_cb, varname);
>> +	if (err == ERR_OK)
>> +		dns_found_cb(name, &ipaddr, varname);
>> +
>> +	/* convert lwIP ERR_INPROGRESS to U-Boot -EINPROGRESS */
>> +	if (err == ERR_INPROGRESS)
>> +		err = -EINPROGRESS;
>> +
>> +	return err;
>> +}
>> --
>> 2.30.2
>>
Maxim Uvarov Sept. 13, 2023, 1:46 p.m. UTC | #3
On Wed, 13 Sept 2023 at 14:32, Simon Goldschmidt <goldsimon@gmx.de> wrote:

>
>
> On 13.09.2023 07:56, Ilias Apalodimas wrote:
> > On Fri, Sep 08, 2023 at 07:53:08PM +0600, Maxim Uvarov wrote:
> >> U-Boot recently got support for an alternative network stack using LWIP.
> >> Replace dns command with the LWIP variant while keeping the output and
> >> error messages identical.
> >>
> >> Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
> >> ---
> >>   include/net/lwip.h           | 19 +++++++++++
> >>   net/lwip/Makefile            |  2 ++
> >>   net/lwip/apps/dns/lwip-dns.c | 63 ++++++++++++++++++++++++++++++++++++
> >>   3 files changed, 84 insertions(+)
> >>   create mode 100644 include/net/lwip.h
> >>   create mode 100644 net/lwip/apps/dns/lwip-dns.c
> >>
> >> diff --git a/include/net/lwip.h b/include/net/lwip.h
> >> new file mode 100644
> >> index 0000000000..ab3db1a214
> >> --- /dev/null
> >> +++ b/include/net/lwip.h
> >> @@ -0,0 +1,19 @@
> >> +/* SPDX-License-Identifier: GPL-2.0 */
> >> +
> >> +int do_lwip_dns(struct cmd_tbl *cmdtp, int flag, int argc,
> >> +            char *const argv[]);
> >> +
> >> +/**
> >> + * ulwip_dns() - creates the DNS request to resolve a domain host name
> >> + *
> >> + * This function creates the DNS request to resolve a domain host
> name. Function
> >> + * can return immediately if previous request was cached or it might
> require
> >> + * entering the polling loop for a request to a remote server.
> >> + *
> >> + * @name:    dns name to resolve
> >> + * @varname: (optional) U-Boot variable name to store the result
> >> + * Returns: ERR_OK(0) for fetching entry from the cache
> >> + *          -EINPROGRESS success, can go to the polling loop
> >> + *          Other value < 0, if error
> >> + */
> >> +int ulwip_dns(char *name, char *varname);
> >> diff --git a/net/lwip/Makefile b/net/lwip/Makefile
> >> index 3fd5d34564..5d8d5527c6 100644
> >> --- a/net/lwip/Makefile
> >> +++ b/net/lwip/Makefile
> >> @@ -62,3 +62,5 @@ obj-$(CONFIG_NET) +=
> lwip-external/src/netif/ethernet.o
> >>
> >>   obj-$(CONFIG_NET) += port/if.o
> >>   obj-$(CONFIG_NET) += port/sys-arch.o
> >> +
> >> +obj-y += apps/dns/lwip-dns.o
> >> diff --git a/net/lwip/apps/dns/lwip-dns.c b/net/lwip/apps/dns/lwip-dns.c
> >> new file mode 100644
> >> index 0000000000..b340302f2c
> >> --- /dev/null
> >> +++ b/net/lwip/apps/dns/lwip-dns.c
> >> @@ -0,0 +1,63 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +
> >> +/*
> >> + * (C) Copyright 2023 Linaro Ltd. <maxim.uvarov@linaro.org>
> >> + */
> >> +
> >> +#include <common.h>
> >> +#include <command.h>
> >> +#include <console.h>
> >> +
> >> +#include <lwip/dns.h>
> >> +#include <lwip/ip_addr.h>
> >> +
> >> +#include <net/ulwip.h>
> >> +
> >> +static void dns_found_cb(const char *name, const ip_addr_t *ipaddr,
> void *callback_arg)
> >> +{
> >> +    char *varname = (char *)callback_arg;
> >> +    char *ipstr = ip4addr_ntoa(ipaddr);
> >> +
> >> +    if (varname)
> >> +            env_set(varname, ipstr);
> >> +    log_info("resolved %s to %s\n",  name, ipstr);
> >> +    ulwip_exit(0);
> >> +}
> >> +
> >> +int ulwip_dns(char *name, char *varname)
> >> +{
> >> +    int err;
> >> +    ip_addr_t ipaddr; /* not used */
> >> +    ip_addr_t dns1;
> >> +    ip_addr_t dns2;
> >> +    char *dnsenv = env_get("dnsip");
> >> +    char *dns2env = env_get("dnsip2");
> >> +
> >> +    if (!dnsenv && !dns2env) {
> >> +            log_err("nameserver is not set with dnsip and dnsip2
> vars\n");
> >> +            return -ENOENT;
> >> +    }
> >> +
> >> +    if (!dnsenv)
> >> +            log_warning("dnsip var is not set\n");
> >> +    if (!dns2env)
> >> +            log_warning("dnsip2 var is not set\n");
> >> +
> >> +    dns_init();
> >> +
> >> +    if (ipaddr_aton(dnsenv, &dns1))
> >> +            dns_setserver(0, &dns1);
> >> +
> >> +    if (ipaddr_aton(dns2env, &dns2))
> >> +            dns_setserver(1, &dns2);
> >
> > env_get will return NULL if any of these is not set.  Looking at
> > ipaddr_aton() of lwip that might lead to a NULL deref in ip_2_ip6()
>
> Looking at the NULL checks in ipaddr_aton(), you found a bug in lwIP.
> I'd vote to leave the above code as is and rely on the bug being fixed
> in lwIP before U-Boot enables IPv6 (this is only a bug in dual-stack
> mode where IPv4 and IPv6 is enabled).
>
> Regards,
> Simon
>
>
Yes, I looked for an ipv4 case with null check.  But I think here we can go
with:
if (dns2env && ipaddr_aton(dns2env, &dns2))



> >
> >> +
> >> +    err = dns_gethostbyname(name, &ipaddr, dns_found_cb, varname);
> >> +    if (err == ERR_OK)
> >> +            dns_found_cb(name, &ipaddr, varname);
> >> +
> >> +    /* convert lwIP ERR_INPROGRESS to U-Boot -EINPROGRESS */
> >> +    if (err == ERR_INPROGRESS)
> >> +            err = -EINPROGRESS;
> >> +
> >> +    return err;
> >> +}
> >> --
> >> 2.30.2
> >>
>
diff mbox series

Patch

diff --git a/include/net/lwip.h b/include/net/lwip.h
new file mode 100644
index 0000000000..ab3db1a214
--- /dev/null
+++ b/include/net/lwip.h
@@ -0,0 +1,19 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+int do_lwip_dns(struct cmd_tbl *cmdtp, int flag, int argc,
+		char *const argv[]);
+
+/**
+ * ulwip_dns() - creates the DNS request to resolve a domain host name
+ *
+ * This function creates the DNS request to resolve a domain host name. Function
+ * can return immediately if previous request was cached or it might require
+ * entering the polling loop for a request to a remote server.
+ *
+ * @name:    dns name to resolve
+ * @varname: (optional) U-Boot variable name to store the result
+ * Returns: ERR_OK(0) for fetching entry from the cache
+ *          -EINPROGRESS success, can go to the polling loop
+ *          Other value < 0, if error
+ */
+int ulwip_dns(char *name, char *varname);
diff --git a/net/lwip/Makefile b/net/lwip/Makefile
index 3fd5d34564..5d8d5527c6 100644
--- a/net/lwip/Makefile
+++ b/net/lwip/Makefile
@@ -62,3 +62,5 @@  obj-$(CONFIG_NET) += lwip-external/src/netif/ethernet.o
 
 obj-$(CONFIG_NET) += port/if.o
 obj-$(CONFIG_NET) += port/sys-arch.o
+
+obj-y += apps/dns/lwip-dns.o
diff --git a/net/lwip/apps/dns/lwip-dns.c b/net/lwip/apps/dns/lwip-dns.c
new file mode 100644
index 0000000000..b340302f2c
--- /dev/null
+++ b/net/lwip/apps/dns/lwip-dns.c
@@ -0,0 +1,63 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * (C) Copyright 2023 Linaro Ltd. <maxim.uvarov@linaro.org>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <console.h>
+
+#include <lwip/dns.h>
+#include <lwip/ip_addr.h>
+
+#include <net/ulwip.h>
+
+static void dns_found_cb(const char *name, const ip_addr_t *ipaddr, void *callback_arg)
+{
+	char *varname = (char *)callback_arg;
+	char *ipstr = ip4addr_ntoa(ipaddr);
+
+	if (varname)
+		env_set(varname, ipstr);
+	log_info("resolved %s to %s\n",  name, ipstr);
+	ulwip_exit(0);
+}
+
+int ulwip_dns(char *name, char *varname)
+{
+	int err;
+	ip_addr_t ipaddr; /* not used */
+	ip_addr_t dns1;
+	ip_addr_t dns2;
+	char *dnsenv = env_get("dnsip");
+	char *dns2env = env_get("dnsip2");
+
+	if (!dnsenv && !dns2env) {
+		log_err("nameserver is not set with dnsip and dnsip2 vars\n");
+		return -ENOENT;
+	}
+
+	if (!dnsenv)
+		log_warning("dnsip var is not set\n");
+	if (!dns2env)
+		log_warning("dnsip2 var is not set\n");
+
+	dns_init();
+
+	if (ipaddr_aton(dnsenv, &dns1))
+		dns_setserver(0, &dns1);
+
+	if (ipaddr_aton(dns2env, &dns2))
+		dns_setserver(1, &dns2);
+
+	err = dns_gethostbyname(name, &ipaddr, dns_found_cb, varname);
+	if (err == ERR_OK)
+		dns_found_cb(name, &ipaddr, varname);
+
+	/* convert lwIP ERR_INPROGRESS to U-Boot -EINPROGRESS */
+	if (err == ERR_INPROGRESS)
+		err = -EINPROGRESS;
+
+	return err;
+}