Re: [PATCH v2 2/3] net: dhcp6: pxe: Add DHCP/PXE commands for IPv6

Simon Glass
2023-04-07T18:56:29Z

Hi Sean,

On Fri, 7 Apr 2023 at 18:56, <seanedmond@linux.microsoft.com> wrote:
>
> From: Sean Edmond <seanedmond@microsoft.com>
>
> Adds commands to support DHCP and PXE with IPv6.
>
> New configs added:
> - CMD_DHCP6
> - DHCP6_PXE_CLIENTARCH
> - DHCP6_PXE_DHCP_OPTION
> - DHCP6_ENTERPRISE_ID
>
> New commands added (when IPv6 is enabled):
> - dhcp6
> - pxe get -ipv6
> - pxe boot -ipv6
>
> Signed-off-by: Sean Edmond <seanedmond@microsoft.com>
> ---
> boot/bootmeth_distro.c | 2 +-
> boot/bootmeth_pxe.c | 4 +-
> boot/pxe_utils.c | 3 +-
> cmd/Kconfig | 26 +++++++++++++
> cmd/net.c | 23 +++++++++++
> cmd/pxe.c | 86 +++++++++++++++++++++++++++++++++++++-----
> cmd/sysboot.c | 2 +-
> include/pxe_utils.h | 10 ++++-
> 8 files changed, 140 insertions(+), 16 deletions(-)

With nits below:

Reviewed-by: Simon Glass <sjg@chromium.org>

[..]

> +if CMD_DHCP6
> +
> +config DHCP6_PXE_CLIENTARCH
> + hex
> + default 0x16 if ARM64
> + default 0x15 if ARM
> + default 0xFF

Do we need a separate option or could we use BOOTP_PXE_CLIENTARCH ?

> +
> +config DHCP6_PXE_DHCP_OPTION
> + bool "Request & store 'pxe_configfile' from DHCP6 server"
> +
> +config DHCP6_ENTERPRISE_ID
> + int "Enterprise ID to send in DHCPv6 Vendor Class Option"
> + default 0
> +
> +endif
> +
> config CMD_TFTPBOOT
> bool "tftpboot"
> default y
> diff --git a/cmd/net.c b/cmd/net.c
> index d5e20843dd..95529a9d12 100644
> --- a/cmd/net.c
> +++ b/cmd/net.c
> @@ -111,6 +111,29 @@ U_BOOT_CMD(
> );
> #endif
>
> +#if defined(CONFIG_CMD_DHCP6)
> +static int do_dhcp6(struct cmd_tbl *cmdtp, int flag, int argc,
> + char *const argv[])
> +{
> + int i;
> + int dhcp_argc;
> + char *dhcp_argv[] = {NULL, NULL, NULL, NULL};
> +
> + /* Add -ipv6 flag for autoload */
> + for (i = 0; i < argc; i++)
> + dhcp_argv[i] = argv[i];
> + dhcp_argc = argc + 1;
> + dhcp_argv[dhcp_argc - 1] = USE_IP6_CMD_PARAM;
> +
> + return netboot_common(DHCP6, cmdtp, dhcp_argc, dhcp_argv);
> +}
> +
> +U_BOOT_CMD(dhcp6, 3, 1, do_dhcp6,
> + "boot image via network using DHCPv6/TFTP protocol. \n"
> + "Use IPv6 hostIPaddr framed with [] brackets",
> + "[loadAddress] [[hostIPaddr:]bootfilename]");
> +#endif
> +
> #if defined(CONFIG_CMD_DHCP)
> static int do_dhcp(struct cmd_tbl *cmdtp, int flag, int argc,
> char *const argv[])
> diff --git a/cmd/pxe.c b/cmd/pxe.c
> index db8e4697f2..71e6fd9633 100644
> --- a/cmd/pxe.c
> +++ b/cmd/pxe.c
> @@ -8,6 +8,7 @@
> #include <command.h>
> #include <fs.h>
> #include <net.h>
> +#include <net6.h>
>
> #include "pxe_utils.h"
>
> @@ -29,12 +30,20 @@ static int do_get_tftp(struct pxe_context *ctx, const char *file_path,
> {
> char *tftp_argv[] = {"tftp", NULL, NULL, NULL};
> int ret;
> + int num_args;
>
> tftp_argv[1] = file_addr;
> tftp_argv[2] = (void *)file_path;
> + if (ctx->use_ipv6) {
> + tftp_argv[3] = USE_IP6_CMD_PARAM;
> + num_args = 4;
> + } else {
> + num_args = 3;
> + }
>
> - if (do_tftpb(ctx->cmdtp, 0, 3, tftp_argv))
> + if (do_tftpb(ctx->cmdtp, 0, num_args, tftp_argv))
> return -ENOENT;
> +
> ret = pxe_get_file_size(sizep);
> if (ret)
> return log_msg_ret("tftp", ret);
> @@ -43,6 +52,23 @@ static int do_get_tftp(struct pxe_context *ctx, const char *file_path,
> return 1;
> }
>
> +#if defined(CONFIG_DHCP6_PXE_DHCP_OPTION)
> +/*
> + * Looks for a pxe file with specified config file name,
> + * which is received from DHCPv4 option 209 or
> + * DHCPv6 option 60.
> + *
> + * Returns 1 on success or < 0 on error.
> + */
> +static inline int pxe_dhcp_option_path(struct pxe_context *ctx, unsigned long pxefile_addr_r)

Please drop the inline as the compiler can handle that.

> +{
> + int ret = get_pxe_file(ctx, pxelinux_configfile, pxefile_addr_r);
> +
> + free(pxelinux_configfile);
> +
> + return ret;
> +}
> +#endif
> /*
> * Looks for a pxe file with a name based on the pxeuuid environment variable.
> *
> @@ -105,15 +131,25 @@ static int pxe_ipaddr_paths(struct pxe_context *ctx, unsigned long pxefile_addr_
> return -ENOENT;
> }
>
> -int pxe_get(ulong pxefile_addr_r, char **bootdirp, ulong *sizep)
> +int pxe_get(ulong pxefile_addr_r, char **bootdirp, ulong *sizep, bool use_ipv6)
> {
> struct cmd_tbl cmdtp[] = {}; /* dummy */
> struct pxe_context ctx;
> int i;
>
> if (pxe_setup_ctx(&ctx, cmdtp, do_get_tftp, NULL, false,
> - env_get("bootfile")))
> + env_get("bootfile"), use_ipv6))
> return -ENOMEM;
> +
> +#if defined(CONFIG_DHCP6_PXE_DHCP_OPTION)

It's a bit annoying that pxelinux_configfile causes these #ifdefs. How
about always having pxelinux_configfile and then you don't need to
worry. It can just be NULL when not used. It is only BSS space, after
all...

> + if (pxelinux_configfile && use_ipv6) {
> + if (pxe_dhcp_option_path(&ctx, pxefile_addr_r) > 0)
> + goto done;
> +
> + goto error_exit;
> + }
> +#endif
> +
> /*
> * Keep trying paths until we successfully get a file we're looking
> * for.
> @@ -131,9 +167,12 @@ int pxe_get(ulong pxefile_addr_r, char **bootdirp, ulong *sizep)
> i++;
> }
>
> +#if defined(CONFIG_DHCP6_PXE_DHCP_OPTION)

...then you can use if (IS_ENABLED(... here

> +error_exit:
> pxe_destroy_ctx(&ctx);
>
> return -ENOENT;
> +#endif
> done:
> *bootdirp = env_get("bootfile");
>
> @@ -169,9 +208,17 @@ do_pxe_get(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> char *fname;
> ulong size;
> int ret;
> + bool use_ipv6 = false;
>
> - if (argc != 1)
> - return CMD_RET_USAGE;
> + if (IS_ENABLED(CONFIG_IPV6)) {
> + if (argc != 1 && argc != 2)
> + return CMD_RET_USAGE;
> + if (!strcmp(argv[argc - 1], USE_IP6_CMD_PARAM))
> + use_ipv6 = true;
> + } else {
> + if (argc != 1)
> + return CMD_RET_USAGE;
> + }
>
> pxefile_addr_str = from_env("pxefile_addr_r");
>
> @@ -183,7 +230,7 @@ do_pxe_get(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> if (ret < 0)
> return 1;
>
> - ret = pxe_get(pxefile_addr_r, &fname, &size);
> + ret = pxe_get(pxefile_addr_r, &fname, &size, use_ipv6);
> switch (ret) {
> case 0:
> printf("Config file '%s' found\n", fname);
> @@ -211,13 +258,19 @@ do_pxe_boot(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> char *pxefile_addr_str;
> struct pxe_context ctx;
> int ret;
> + bool use_ipv6 = false;
> +
> + if (IS_ENABLED(CONFIG_IPV6)) {
> + if (!strcmp(argv[argc - 1], USE_IP6_CMD_PARAM))
> + use_ipv6 = true;
> + }
>
> - if (argc == 1) {
> + if (argc == 1 || (argc == 2 && use_ipv6)) {
> pxefile_addr_str = from_env("pxefile_addr_r");
> if (!pxefile_addr_str)
> return 1;
>
> - } else if (argc == 2) {
> + } else if (argc == 2 || (argc == 3 && use_ipv6)) {
> pxefile_addr_str = argv[1];
> } else {
> return CMD_RET_USAGE;
> @@ -229,7 +282,7 @@ do_pxe_boot(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> }
>
> if (pxe_setup_ctx(&ctx, cmdtp, do_get_tftp, NULL, false,
> - env_get("bootfile"))) {
> + env_get("bootfile"), use_ipv6)) {
> printf("Out of memory\n");
> return CMD_RET_FAILURE;
> }
> @@ -244,8 +297,13 @@ do_pxe_boot(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> }
>
> static struct cmd_tbl cmd_pxe_sub[] = {
> +#if IS_ENABLED(CONFIG_IPV6)
> + U_BOOT_CMD_MKENT(get, 2, 1, do_pxe_get, "", ""),
> + U_BOOT_CMD_MKENT(boot, 3, 1, do_pxe_boot, "", "")
> +#else
> U_BOOT_CMD_MKENT(get, 1, 1, do_pxe_get, "", ""),
> U_BOOT_CMD_MKENT(boot, 2, 1, do_pxe_boot, "", "")
> +#endif

That's a bit ugly. How about using the max and then checking it in the C code?

> };
>
> static void __maybe_unused pxe_reloc(void)
> @@ -281,9 +339,19 @@ static int do_pxe(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> return CMD_RET_USAGE;
> }
>
> +#if IS_ENABLED(CONFIG_IPV6)
> +U_BOOT_CMD(pxe, 4, 1, do_pxe,
> + "commands to get and boot from pxe files\n"
> + "To use IPv6 add -ipv6 parameter",
> + "get [" USE_IP6_CMD_PARAM "] - try to retrieve a pxe file using tftp\n"
> + "pxe boot [pxefile_addr_r] [-ipv6] - boot from the pxe file at pxefile_addr_r\n"
> +);
> +#else
> U_BOOT_CMD(pxe, 3, 1, do_pxe,
> "commands to get and boot from pxe files",
> "get - try to retrieve a pxe file using tftp\n"
> "pxe boot [pxefile_addr_r] - boot from the pxe file at pxefile_addr_r\n"
> );
> #endif

same here

> +
> +#endif /* CONFIG_CMD_NET */

[..]

Regards,
Simon