From a8d55f4a10078affc7e4f9e30988f0f55a67863a Mon Sep 17 00:00:00 2001 From: wangjianyu3 Date: Mon, 10 Aug 2026 16:33:01 +0800 Subject: [PATCH] nshlib/ifconfig: only apply the settings that were asked for cmd_ifconfig() pushed every setting to the device on each invocation, whether or not the command line carried it, and stopped parsing as soon as it saw "mtu". So a command meant to touch one thing quietly rewrote the rest of the interface configuration: ifconfig eth0 hw 00:11:22:33:44:55 # clears the address, netmask, # gateway and resolver, and kicks # off a DHCP request ifconfig eth0 mtu 1500 # same, plus the default route ifconfig eth0 mtu 1500 dns 8.8.8.8 # dns silently ignored In detail: - the address was written unconditionally. For IPv6 that read the uninitialized addr6 off the stack and pushed whatever it held into the device; for IPv4 it forced 0.0.0.0. - the netmask fell back to a hard-coded 255.255.255.0, or to ffff:ffff:ffff:ffff:: for IPv6. - the IPv4 gateway was always written, unlike the IPv6 one, so it fell back to INADDR_ANY. - the resolver fell back to that gateway, i.e. to 0.0.0.0. - the DHCP client was started whenever gip was left at zero instead of when "dhcp" was asked for, and gip only becomes non-zero when an address or a gateway is parsed. - the "mtu" branch returned as soon as netlib_set_mtu() succeeded, so every argument behind it was dropped. Write each setting only when the user provided it, or when an address is being assigned and the setting belongs to it. Keeping the address case is deliberate: a freshly assigned address still needs a mask and a route, so dropping the derived netmask and "x.x.x.1" gateway there would be a regression of its own. DHCP now triggers on the "dhcp" keyword, which is the only way to request it. And with nothing left to clobber, the "mtu" branch no longer has to bail out early. This is how ifconfig behaves elsewhere: Linux net-tools walks the argument vector in a single loop where every keyword handler ends in "continue" and none of them returns, so each keyword is an independent, idempotent operation applied in the order it was written. As a side effect mip is now only read along the paths that assign it, since the IPv4 gateway fallback only derives an address from mip when gip came from hostip. Assisted-by: GitHubCopilot:claude-opus-5 Signed-off-by: wangjianyu3 --- nshlib/nsh_netcmds.c | 89 ++++++++++++++++++++++---------------------- 1 file changed, 45 insertions(+), 44 deletions(-) diff --git a/nshlib/nsh_netcmds.c b/nshlib/nsh_netcmds.c index 8e25c69a2..b7f92f5ca 100644 --- a/nshlib/nsh_netcmds.c +++ b/nshlib/nsh_netcmds.c @@ -557,7 +557,7 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) #ifdef CONFIG_NET_IPv4 struct in_addr addr; in_addr_t gip = INADDR_ANY; - in_addr_t mip; + in_addr_t mip = INADDR_ANY; #endif #ifdef CONFIG_NET_IPv6 struct in6_addr addr6; @@ -809,7 +809,6 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) if (mtu != 0) { netlib_set_mtu(ifname, mtu); - return OK; } /* Set IP address */ @@ -839,11 +838,11 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) nsh_error(vtbl, g_fmtarginvalid, argv[0]); return ERROR; } - } #ifndef CONFIG_NETDEV_MULTIPLE_IPv6 - netlib_set_ipv6addr(ifname, &addr6); + netlib_set_ipv6addr(ifname, &addr6); #endif + } } #endif /* CONFIG_NET_IPv6 */ @@ -851,31 +850,25 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) #ifdef CONFIG_NET_IPv6 else #endif + if (hostip != NULL) { - if (hostip != NULL) - { #if defined(CONFIG_NETUTILS_DHCPC) - if (strcmp(hostip, "dhcp") == 0) - { - /* Set DHCP addr */ + if (strcmp(hostip, "dhcp") == 0) + { + /* Set DHCP addr */ - ninfo("DHCPC Mode\n"); - addr.s_addr = 0; - gip = 0; - } - else -#endif - { - /* Set host IP address */ - - ninfo("Host IP: %s\n", hostip); - addr.s_addr = inet_addr(hostip); - gip = addr.s_addr; - } + ninfo("DHCPC Mode\n"); + addr.s_addr = 0; + gip = 0; } else +#endif { - addr.s_addr = 0; + /* Set host IP address */ + + ninfo("Host IP: %s\n", hostip); + addr.s_addr = inet_addr(hostip); + gip = addr.s_addr; } netlib_set_ipv4addr(ifname, &addr); @@ -908,33 +901,39 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) ninfo("Prefixlen: %s\n", preflen); netlib_prefix2ipv6netmask(atoi(preflen), &mask6); } - else + else if (hostip != NULL) { ninfo("Netmask: Default\n"); inet_pton(AF_INET6, "ffff:ffff:ffff:ffff::", &mask6); } #ifdef CONFIG_NETDEV_MULTIPLE_IPv6 - plen = netlib_ipv6netmask2prefix(mask6.in6_u.u6_addr16); - if (remove) + if (hostip != NULL) { - ret = netlib_del_ipv6addr(ifname, &addr6, plen); - } - else - { - ret = netlib_add_ipv6addr(ifname, &addr6, plen); - } + plen = netlib_ipv6netmask2prefix(mask6.in6_u.u6_addr16); + if (remove) + { + ret = netlib_del_ipv6addr(ifname, &addr6, plen); + } + else + { + ret = netlib_add_ipv6addr(ifname, &addr6, plen); + } - if (ret < 0) - { - perror("Failed to manage IPv6 address"); + if (ret < 0) + { + perror("Failed to manage IPv6 address"); - /* REVISIT: Should we return ERROR or just let it go? */ + /* REVISIT: Should we return ERROR or just let it go? */ - return ERROR; + return ERROR; + } } #else - netlib_set_ipv6netmask(ifname, &mask6); + if (mask != NULL || preflen != NULL || hostip != NULL) + { + netlib_set_ipv6netmask(ifname, &mask6); + } #endif /* CONFIG_NETDEV_MULTIPLE_IPv6 */ } #endif /* CONFIG_NET_IPv6 */ @@ -943,6 +942,7 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) #ifdef CONFIG_NET_IPv6 else #endif + if (mask != NULL || hostip != NULL) { if (mask != NULL) { @@ -989,6 +989,7 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) #ifdef CONFIG_NET_IPv6 else #endif + if (gwip != NULL || hostip != NULL) { if (gwip != NULL) { @@ -1030,14 +1031,14 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) nsh_error(vtbl, g_fmtarginvalid, argv[0]); return ERROR; } + + netlib_set_ipv6dnsaddr(&addr6); } - else + else if (hostip != NULL) { ninfo("DNS: Default\n"); - addr6 = gip6; + netlib_set_ipv6dnsaddr(&gip6); } - - netlib_set_ipv6dnsaddr(&addr6); } #endif /* CONFIG_NET_IPv6 */ @@ -1045,6 +1046,7 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) #ifdef CONFIG_NET_IPv6 else #endif + if (dns != NULL || hostip != NULL) { if (dns != NULL) { @@ -1063,8 +1065,7 @@ int cmd_ifconfig(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv) #endif /* CONFIG_NETDB_DNSCLIENT */ #if defined(CONFIG_NETUTILS_DHCPC) - - if (!gip) + if (hostip != NULL && strcmp(hostip, "dhcp") == 0) { netlib_obtain_ipv4addr(ifname); }