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 dnsip2vars\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