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Diffstat (limited to 'common/cmd_pxe.c')
| -rw-r--r-- | common/cmd_pxe.c | 1355 |
1 files changed, 1355 insertions, 0 deletions
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c new file mode 100644 index 000000000..3efd7008e --- /dev/null +++ b/common/cmd_pxe.c @@ -0,0 +1,1355 @@ +/* + * Copyright 2010-2011 Calxeda, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <common.h> +#include <command.h> +#include <malloc.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <errno.h> +#include <linux/list.h> + +#include "menu.h" + +#define MAX_TFTP_PATH_LEN 127 + + +/* + * Like getenv, but prints an error if envvar isn't defined in the + * environment. It always returns what getenv does, so it can be used in + * place of getenv without changing error handling otherwise. + */ +static char *from_env(char *envvar) +{ + char *ret; + + ret = getenv(envvar); + + if (!ret) + printf("missing environment variable: %s\n", envvar); + + return ret; +} + +/* + * Convert an ethaddr from the environment to the format used by pxelinux + * filenames based on mac addresses. Convert's ':' to '-', and adds "01-" to + * the beginning of the ethernet address to indicate a hardware type of + * Ethernet. Also converts uppercase hex characters into lowercase, to match + * pxelinux's behavior. + * + * Returns 1 for success, -ENOENT if 'ethaddr' is undefined in the + * environment, or some other value < 0 on error. + */ +static int format_mac_pxe(char *outbuf, size_t outbuf_len) +{ + size_t ethaddr_len; + char *p, *ethaddr; + + ethaddr = from_env("ethaddr"); + + if (!ethaddr) + return -ENOENT; + + ethaddr_len = strlen(ethaddr); + + /* + * ethaddr_len + 4 gives room for "01-", ethaddr, and a NUL byte at + * the end. + */ + if (outbuf_len < ethaddr_len + 4) { + printf("outbuf is too small (%d < %d)\n", + outbuf_len, ethaddr_len + 4); + + return -EINVAL; + } + + strcpy(outbuf, "01-"); + + for (p = outbuf + 3; *ethaddr; ethaddr++, p++) { + if (*ethaddr == ':') + *p = '-'; + else + *p = tolower(*ethaddr); + } + + *p = '\0'; + + return 1; +} + +/* + * Returns the directory the file specified in the bootfile env variable is + * in. If bootfile isn't defined in the environment, return NULL, which should + * be interpreted as "don't prepend anything to paths". + */ +static int get_bootfile_path(char *bootfile_path, size_t bootfile_path_size) +{ + char *bootfile, *last_slash; + size_t path_len; + + bootfile = from_env("bootfile"); + + if (!bootfile) { + bootfile_path[0] = '\0'; + return 1; + } + + last_slash = strrchr(bootfile, '/'); + + if (last_slash == NULL) { + bootfile_path[0] = '\0'; + return 1; + } + + path_len = (last_slash - bootfile) + 1; + + if (bootfile_path_size < path_len) { + printf("bootfile_path too small. (%d < %d)\n", + bootfile_path_size, path_len); + + return -1; + } + + strncpy(bootfile_path, bootfile, path_len); + + bootfile_path[path_len] = '\0'; + + return 1; +} + +/* + * As in pxelinux, paths to files referenced from files we retrieve are + * relative to the location of bootfile. get_relfile takes such a path and + * joins it with the bootfile path to get the full path to the target file. If + * the bootfile path is NULL, we use file_path as is. + * + * Returns 1 for success, or < 0 on error. + */ +static int get_relfile(char *file_path, void *file_addr) +{ + size_t path_len; + char relfile[MAX_TFTP_PATH_LEN+1]; + char addr_buf[10]; + char *tftp_argv[] = {"tftp", NULL, NULL, NULL}; + int err; + + err = get_bootfile_path(relfile, sizeof(relfile)); + + if (err < 0) + return err; + + path_len = strlen(file_path); + path_len += strlen(relfile); + + if (path_len > MAX_TFTP_PATH_LEN) { + printf("Base path too long (%s%s)\n", + relfile, + file_path); + + return -ENAMETOOLONG; + } + + strcat(relfile, file_path); + + printf("Retrieving file: %s\n", relfile); + + sprintf(addr_buf, "%p", file_addr); + + tftp_argv[1] = addr_buf; + tftp_argv[2] = relfile; + + if (do_tftpb(NULL, 0, 3, tftp_argv)) + return -ENOENT; + + return 1; +} + +/* + * Retrieve the file at 'file_path' to the locate given by 'file_addr'. If + * 'bootfile' was specified in the environment, the path to bootfile will be + * prepended to 'file_path' and the resulting path will be used. + * + * Returns 1 on success, or < 0 for error. + */ +static int get_pxe_file(char *file_path, void *file_addr) +{ + unsigned long config_file_size; + char *tftp_filesize; + int err; + + err = get_relfile(file_path, file_addr); + + if (err < 0) + return err; + + /* + * the file comes without a NUL byte at the end, so find out its size + * and add the NUL byte. + */ + tftp_filesize = from_env("filesize"); + + if (!tftp_filesize) + return -ENOENT; + + if (strict_strtoul(tftp_filesize, 16, &config_file_size) < 0) + return -EINVAL; + + *(char *)(file_addr + config_file_size) = '\0'; + + return 1; +} + +#define PXELINUX_DIR "pxelinux.cfg/" + +/* + * Retrieves a file in the 'pxelinux.cfg' folder. Since this uses get_pxe_file + * to do the hard work, the location of the 'pxelinux.cfg' folder is generated + * from the bootfile path, as described above. + * + * Returns 1 on success or < 0 on error. + */ +static int get_pxelinux_path(char *file, void *pxefile_addr_r) +{ + size_t base_len = strlen(PXELINUX_DIR); + char path[MAX_TFTP_PATH_LEN+1]; + + if (base_len + strlen(file) > MAX_TFTP_PATH_LEN) { + printf("path (%s%s) too long, skipping\n", + PXELINUX_DIR, file); + return -ENAMETOOLONG; + } + + sprintf(path, PXELINUX_DIR "%s", file); + + return get_pxe_file(path, pxefile_addr_r); +} + +/* + * Looks for a pxe file with a name based on the pxeuuid environment variable. + * + * Returns 1 on success or < 0 on error. + */ +static int pxe_uuid_path(void *pxefile_addr_r) +{ + char *uuid_str; + + uuid_str = from_env("pxeuuid"); + + if (!uuid_str) + return -ENOENT; + + return get_pxelinux_path(uuid_str, pxefile_addr_r); +} + +/* + * Looks for a pxe file with a name based on the 'ethaddr' environment + * variable. + * + * Returns 1 on success or < 0 on error. + */ +static int pxe_mac_path(void *pxefile_addr_r) +{ + char mac_str[21]; + int err; + + err = format_mac_pxe(mac_str, sizeof(mac_str)); + + if (err < 0) + return err; + + return get_pxelinux_path(mac_str, pxefile_addr_r); +} + +/* + * Looks for pxe files with names based on our IP address. See pxelinux + * documentation for details on what these file names look like. We match + * that exactly. + * + * Returns 1 on success or < 0 on error. + */ +static int pxe_ipaddr_paths(void *pxefile_addr_r) +{ + char ip_addr[9]; + int mask_pos, err; + + sprintf(ip_addr, "%08X", ntohl(NetOurIP)); + + for (mask_pos = 7; mask_pos >= 0; mask_pos--) { + err = get_pxelinux_path(ip_addr, pxefile_addr_r); + + if (err > 0) + return err; + + ip_addr[mask_pos] = '\0'; + } + + return -ENOENT; +} + +/* + * Entry point for the 'pxe get' command. + * This Follows pxelinux's rules to download a config file from a tftp server. + * The file is stored at the location given by the pxefile_addr_r environment + * variable, which must be set. + * + * UUID comes from pxeuuid env variable, if defined + * MAC addr comes from ethaddr env variable, if defined + * IP + * + * see http://syslinux.zytor.com/wiki/index.php/PXELINUX + * + * Returns 0 on success or 1 on error. + */ +static int +do_pxe_get(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{ + char *pxefile_addr_str; + void *pxefile_addr_r; + int err; + + if (argc != 1) + return cmd_usage(cmdtp); + + + pxefile_addr_str = from_env("pxefile_addr_r"); + + if (!pxefile_addr_str) + return 1; + + err = strict_strtoul(pxefile_addr_str, 16, + (unsigned long *)&pxefile_addr_r); + if (err < 0) + return 1; + + /* + * Keep trying paths until we successfully get a file we're looking + * for. + */ + if (pxe_uuid_path(pxefile_addr_r) > 0 + || pxe_mac_path(pxefile_addr_r) > 0 + || pxe_ipaddr_paths(pxefile_addr_r) > 0 + || get_pxelinux_path("default", pxefile_addr_r) > 0) { + + printf("Config file found\n"); + + return 0; + } + + printf("Config file not found\n"); + + return 1; +} + +/* + * Wrapper to make it easier to store the file at file_path in the location + * specified by envaddr_name. file_path will be joined to the bootfile path, + * if any is specified. + * + * Returns 1 on success or < 0 on error. + */ +static int get_relfile_envaddr(char *file_path, char *envaddr_name) +{ + void *file_addr; + char *envaddr; + + envaddr = from_env(envaddr_name); + + if (!envaddr) + return -ENOENT; + + if (strict_strtoul(envaddr, 16, (unsigned long *)&file_addr) < 0) + return -EINVAL; + + return get_relfile(file_path, file_addr); +} + +/* + * A note on the pxe file parser. + * + * We're parsing files that use syslinux grammar, which has a few quirks. + * String literals must be recognized based on context - there is no + * quoting or escaping support. There's also nothing to explicitly indicate + * when a label section completes. We deal with that by ending a label + * section whenever we see a line that doesn't include. + * + * As with the syslinux family, this same file format could be reused in the + * future for non pxe purposes. The only action it takes during parsing that + * would throw this off is handling of include files. It assumes we're using + * pxe, and does a tftp download of a file listed as an include file in the + * middle of the parsing operation. That could be handled by refactoring it to + * take a 'include file getter' function. + */ + +/* + * Describes a single label given in a pxe file. + * + * Create these with the 'label_create' function given below. + * + * name - the name of the menu as given on the 'menu label' line. + * kernel - the path to the kernel file to use for this label. + * append - kernel command line to use when booting this label + * initrd - path to the initrd to use for this label. + * attempted - 0 if we haven't tried to boot this label, 1 if we have. + * localboot - 1 if this label specified 'localboot', 0 otherwise. + * list - lets these form a list, which a pxe_menu struct will hold. + */ +struct pxe_label { + char *name; + char *kernel; + char *append; + char *initrd; + int attempted; + int localboot; + struct list_head list; +}; + +/* + * Describes a pxe menu as given via pxe files. + * + * title - the name of the menu as given by a 'menu title' line. + * default_label - the name of the default label, if any. + * timeout - time in tenths of a second to wait for a user key-press before + * booting the default label. + * prompt - if 0, don't prompt for a choice unless the timeout period is + * interrupted. If 1, always prompt for a choice regardless of + * timeout. + * labels - a list of labels defined for the menu. + */ +struct pxe_menu { + char *title; + char *default_label; + int timeout; + int prompt; + struct list_head labels; +}; + +/* + * Allocates memory for and initializes a pxe_label. This uses malloc, so the + * result must be free()'d to reclaim the memory. + * + * Returns NULL if malloc fails. + */ +static struct pxe_label *label_create(void) +{ + struct pxe_label *label; + + label = malloc(sizeof(struct pxe_label)); + + if (!label) + return NULL; + + memset(label, 0, sizeof(struct pxe_label)); + + return label; +} + +/* + * Free the memory used by a pxe_label, including that used by its name, + * kernel, append and initrd members, if they're non NULL. + * + * So - be sure to only use dynamically allocated memory for the members of + * the pxe_label struct, unless you want to clean it up first. These are + * currently only created by the pxe file parsing code. + */ +static void label_destroy(struct pxe_label *label) +{ + if (label->name) + free(label->name); + + if (label->kernel) + free(label->kernel); + + if (label->append) + free(label->append); + + if (label->initrd) + free(label->initrd); + + free(label); +} + +/* + * Print a label and its string members if they're defined. + * + * This is passed as a callback to the menu code for displaying each + * menu entry. + */ +static void label_print(void *data) +{ + struct pxe_label *label = data; + + printf("Label: %s\n", label->name); + + if (label->kernel) + printf("\tkernel: %s\n", label->kernel); + + if (label->append) + printf("\tappend: %s\n", label->append); + + if (label->initrd) + printf("\tinitrd: %s\n", label->initrd); +} + +/* + * Boot a label that specified 'localboot'. This requires that the 'localcmd' + * environment variable is defined. Its contents will be executed as U-boot + * command. If the label specified an 'append' line, its contents will be + * used to overwrite the contents of the 'bootargs' environment variable prior + * to running 'localcmd'. + * + * Returns 1 on success or < 0 on error. + */ +static int label_localboot(struct pxe_label *label) +{ + char *localcmd, *dupcmd; + int ret; + + localcmd = from_env("localcmd"); + + if (!localcmd) + return -ENOENT; + + /* + * dup the command to avoid any issues with the version of it existing + * in the environment changing during the execution of the command. + */ + dupcmd = strdup(localcmd); + + if (!dupcmd) + return -ENOMEM; + + if (label->append) + setenv("bootargs", label->append); + + printf("running: %s\n", dupcmd); + + ret = run_command2(dupcmd, 0); + + free(dupcmd); + + return ret; +} + +/* + * Boot according to the contents of a pxe_label. + * + * If we can't boot for any reason, we return. A successful boot never + * returns. + * + * The kernel will be stored in the location given by the 'kernel_addr_r' + * environment variable. + * + * If the label specifies an initrd file, it will be stored in the location + * given by the 'ramdisk_addr_r' environment variable. + * + * If the label specifies an 'append' line, its contents will overwrite that + * of the 'bootargs' environment variable. + */ +static void label_boot(struct pxe_label *label) +{ + char *bootm_argv[] = { "bootm", NULL, NULL, NULL, NULL }; + int bootm_argc = 3; + + label_print(label); + + label->attempted = 1; + + if (label->localboot) { + label_localboot(label); + return; + } + + if (label->kernel == NULL) { + printf("No kernel given, skipping %s\n", + label->name); + return; + } + + if (label->initrd) { + if (get_relfile_envaddr(label->initrd, "ramdisk_addr_r") < 0) { + printf("Skipping %s for failure retrieving initrd\n", + label->name); + return; + } + + bootm_argv[2] = getenv("ramdisk_addr_r"); + } else { + bootm_argv[2] = "-"; + } + + if (get_relfile_envaddr(label->kernel, "kernel_addr_r") < 0) { + printf("Skipping %s for failure retrieving kernel\n", + label->name); + return; + } + + if (label->append) + setenv("bootargs", label->append); + + bootm_argv[1] = getenv("kernel_addr_r"); + + /* + * fdt usage is optional. If there is an fdt_addr specified, we will + * pass it along to bootm, and adjust argc appropriately. + */ + bootm_argv[3] = getenv("fdt_addr"); + + if (bootm_argv[3]) + bootm_argc = 4; + + do_bootm(NULL, 0, bootm_argc, bootm_argv); +} + +/* + * Tokens for the pxe file parser. + */ +enum token_type { + T_EOL, + T_STRING, + T_EOF, + T_MENU, + T_TITLE, + T_TIMEOUT, + T_LABEL, + T_KERNEL, + T_APPEND, + T_INITRD, + T_LOCALBOOT, + T_DEFAULT, + T_PROMPT, + T_INCLUDE, + T_INVALID +}; + +/* + * A token - given by a value and a type. + */ +struct token { + char *val; + enum token_type type; +}; + +/* + * Keywords recognized. + */ +static const struct token keywords[] = { + {"menu", T_MENU}, + {"title", T_TITLE}, + {"timeout", T_TIMEOUT}, + {"default", T_DEFAULT}, + {"prompt", T_PROMPT}, + {"label", T_LABEL}, + {"kernel", T_KERNEL}, + {"localboot", T_LOCALBOOT}, + {"append", T_APPEND}, + {"initrd", T_INITRD}, + {"include", T_INCLUDE}, + {NULL, T_INVALID} +}; + +/* + * Since pxe(linux) files don't have a token to identify the start of a + * literal, we have to keep track of when we're in a state where a literal is + * expected vs when we're in a state a keyword is expected. + */ +enum lex_state { + L_NORMAL = 0, + L_KEYWORD, + L_SLITERAL +}; + +/* + * get_string retrieves a string from *p and stores it as a token in + * *t. + * + * get_string used for scanning both string literals and keywords. + * + * Characters from *p are copied into t-val until a character equal to + * delim is found, or a NUL byte is reached. If delim has the special value of + * ' ', any whitespace character will be used as a delimiter. + * + * If lower is unequal to 0, uppercase characters will be converted to + * lowercase in the result. This is useful to make keywords case + * insensitive. + * + * The location of *p is updated to point to the first character after the end + * of the token - the ending delimiter. + * + * On success, the new value of t->val is returned. Memory for t->val is + * allocated using malloc and must be free()'d to reclaim it. If insufficient + * memory is available, NULL is returned. + */ +static char *get_string(char **p, struct token *t, char delim, int lower) +{ + char *b, *e; + size_t len, i; + + /* + * b and e both start at the beginning of the input stream. + * + * e is incremented until we find the ending delimiter, or a NUL byte + * is reached. Then, we take e - b to find the length of the token. + */ + b = e = *p; + + while (*e) { + if ((delim == ' ' && isspace(*e)) || delim == *e) + break; + e++; + } + + len = e - b; + + /* + * Allocate memory to hold the string, and copy it in, converting + * characters to lowercase if lower is != 0. + */ + t->val = malloc(len + 1); + if (!t->val) + return NULL; + + for (i = 0; i < len; i++, b++) { + if (lower) + t->val[i] = tolower(*b); + else + t->val[i] = *b; + } + + t->val[len] = '\0'; + + /* + * Update *p so the caller knows where to continue scanning. + */ + *p = e; + + t->type = T_STRING; + + return t->val; +} + +/* + * Populate a keyword token with a type and value. + */ +static void get_keyword(struct token *t) +{ + int i; + + for (i = 0; keywords[i].val; i++) { + if (!strcmp(t->val, keywords[i].val)) { + t->type = keywords[i].type; + break; + } + } +} + +/* + * Get the next token. We have to keep track of which state we're in to know + * if we're looking to get a string literal or a keyword. + * + * *p is updated to point at the first character after the current token. + */ +static void get_token(char **p, struct token *t, enum lex_state state) +{ + char *c = *p; + + t->type = T_INVALID; + + /* eat non EOL whitespace */ + while (isblank(*c)) + c++; + + /* + * eat comments. note that string literals can't begin with #, but + * can contain a # after their first character. + */ + if (*c == '#') { + while (*c && *c != '\n') + c++; + } + + if (*c == '\n') { + t->type = T_EOL; + c++; + } else if (*c == '\0') { + t->type = T_EOF; + c++; + } else if (state == L_SLITERAL) { + get_string(&c, t, '\n', 0); + } else if (state == L_KEYWORD) { + /* + * when we expect a keyword, we first get the next string + * token delimited by whitespace, and then check if it + * matches a keyword in our keyword list. if it does, it's + * converted to a keyword token of the appropriate type, and + * if not, it remains a string token. + */ + get_string(&c, t, ' ', 1); + get_keyword(t); + } + + *p = c; +} + +/* + * Increment *c until we get to the end of the current line, or EOF. + */ +static void eol_or_eof(char **c) +{ + while (**c && **c != '\n') + (*c)++; +} + +/* + * All of these parse_* functions share some common behavior. + * + * They finish with *c pointing after the token they parse, and return 1 on + * success, or < 0 on error. + */ + +/* + * Parse a string literal and store a pointer it at *dst. String literals + * terminate at the end of the line. + */ +static int parse_sliteral(char **c, char **dst) +{ + struct token t; + char *s = *c; + + get_token(c, &t, L_SLITERAL); + + if (t.type != T_STRING) { + printf("Expected string literal: %.*s\n", (int)(*c - s), s); + return -EINVAL; + } + + *dst = t.val; + + return 1; +} + +/* + * Parse a base 10 (unsigned) integer and store it at *dst. + */ +static int parse_integer(char **c, int *dst) +{ + struct token t; + char *s = *c; + unsigned long temp; + + get_token(c, &t, L_SLITERAL); + + if (t.type != T_STRING) { + printf("Expected string: %.*s\n", (int)(*c - s), s); + return -EINVAL; + } + + if (strict_strtoul(t.val, 10, &temp) < 0) { + printf("Expected unsigned integer: %s\n", t.val); + return -EINVAL; + } + + *dst = (int)temp; + + free(t.val); + + return 1; +} + +static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level); + +/* + * Parse an include statement, and retrieve and parse the file it mentions. + * + * base should point to a location where it's safe to store the file, and + * nest_level should indicate how many nested includes have occurred. For this + * include, nest_level has already been incremented and doesn't need to be + * incremented here. + */ +static int handle_include(char **c, char *base, + struct pxe_menu *cfg, int nest_level) +{ + char *include_path; + char *s = *c; + int err; + + err = parse_sliteral(c, &include_path); + + if (err < 0) { + printf("Expected include path: %.*s\n", + (int)(*c - s), s); + return err; + } + + err = get_pxe_file(include_path, base); + + if (err < 0) { + printf("Couldn't retrieve %s\n", include_path); + return err; + } + + return parse_pxefile_top(base, cfg, nest_level); +} + +/* + * Parse lines that begin with 'menu'. + * + * b and nest are provided to handle the 'menu include' case. + * + * b should be the address where the file currently being parsed is stored. + * + * nest_level should be 1 when parsing the top level pxe file, 2 when parsing + * a file it includes, 3 when parsing a file included by that file, and so on. + */ +static int parse_menu(char **c, struct pxe_menu *cfg, char *b, int nest_level) +{ + struct token t; + char *s = *c; + int err; + + get_token(c, &t, L_KEYWORD); + + switch (t.type) { + case T_TITLE: + err = parse_sliteral(c, &cfg->title); + + break; + + case T_INCLUDE: + err = handle_include(c, b + strlen(b) + 1, cfg, + nest_level + 1); + break; + + default: + printf("Ignoring malformed menu command: %.*s\n", + (int)(*c - s), s); + } + + if (err < 0) + return err; + + eol_or_eof(c); + + return 1; +} + +/* + * Handles parsing a 'menu line' when we're parsing a label. + */ +static int parse_label_menu(char **c, struct pxe_menu *cfg, + struct pxe_label *label) +{ + struct token t; + char *s; + + s = *c; + + get_token(c, &t, L_KEYWORD); + + switch (t.type) { + case T_DEFAULT: + if (cfg->default_label) + free(cfg->default_label); + + cfg->default_label = strdup(label->name); + + if (!cfg->default_label) + return -ENOMEM; + + break; + default: + printf("Ignoring malformed menu command: %.*s\n", + (int)(*c - s), s); + } + + eol_or_eof(c); + + return 0; +} + +/* + * Parses a label and adds it to the list of labels for a menu. + * + * A label ends when we either get to the end of a file, or + * get some input we otherwise don't have a handler defined + * for. + * + */ +static int parse_label(char **c, struct pxe_menu *cfg) +{ + struct token t; + char *s = *c; + struct pxe_label *label; + int err; + + label = label_create(); + if (!label) + return -ENOMEM; + + err = parse_sliteral(c, &label->name); + if (err < 0) { + printf("Expected label name: %.*s\n", (int)(*c - s), s); + label_destroy(label); + return -EINVAL; + } + + list_add_tail(&label->list, &cfg->labels); + + while (1) { + s = *c; + get_token(c, &t, L_KEYWORD); + + err = 0; + switch (t.type) { + case T_MENU: + err = parse_label_menu(c, cfg, label); + break; + + case T_KERNEL: + err = parse_sliteral(c, &label->kernel); + break; + + case T_APPEND: + err = parse_sliteral(c, &label->append); + break; + + case T_INITRD: + err = parse_sliteral(c, &label->initrd); + break; + + case T_LOCALBOOT: + err = parse_integer(c, &label->localboot); + break; + + case T_EOL: + break; + + default: + /* + * put the token back! we don't want it - it's the end + * of a label and whatever token this is, it's + * something for the menu level context to handle. + */ + *c = s; + return 1; + } + + if (err < 0) + return err; + } +} + +/* + * This 16 comes from the limit pxelinux imposes on nested includes. + * + * There is no reason at all we couldn't do more, but some limit helps prevent + * infinite (until crash occurs) recursion if a file tries to include itself. + */ +#define MAX_NEST_LEVEL 16 + +/* + * Entry point for parsing a menu file. nest_level indicates how many times + * we've nested in includes. It will be 1 for the top level menu file. + * + * Returns 1 on success, < 0 on error. + */ +static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level) +{ + struct token t; + char *s, *b, *label_name; + int err; + + b = p; + + if (nest_level > MAX_NEST_LEVEL) { + printf("Maximum nesting (%d) exceeded\n", MAX_NEST_LEVEL); + return -EMLINK; + } + + while (1) { + s = p; + + get_token(&p, &t, L_KEYWORD); + + err = 0; + switch (t.type) { + case T_MENU: + err = parse_menu(&p, cfg, b, nest_level); + break; + + case T_TIMEOUT: + err = parse_integer(&p, &cfg->timeout); + break; + + case T_LABEL: + err = parse_label(&p, cfg); + break; + + case T_DEFAULT: + err = parse_sliteral(&p, &label_name); + + if (label_name) { + if (cfg->default_label) + free(cfg->default_label); + + cfg->default_label = label_name; + } + + break; + + case T_PROMPT: + err = parse_integer(&p, &cfg->prompt); + break; + + case T_EOL: + break; + + case T_EOF: + return 1; + + default: + printf("Ignoring unknown command: %.*s\n", + (int)(p - s), s); + eol_or_eof(&p); + } + + if (err < 0) + return err; + } +} + +/* + * Free the memory used by a pxe_menu and its labels. + */ +static void destroy_pxe_menu(struct pxe_menu *cfg) +{ + struct list_head *pos, *n; + struct pxe_label *label; + + if (cfg->title) + free(cfg->title); + + if (cfg->default_label) + free(cfg->default_label); + + list_for_each_safe(pos, n, &cfg->labels) { + label = list_entry(pos, struct pxe_label, list); + + label_destroy(label); + } + + free(cfg); +} + +/* + * Entry point for parsing a pxe file. This is only used for the top level + * file. + * + * Returns NULL if there is an error, otherwise, returns a pointer to a + * pxe_menu struct populated with the results of parsing the pxe file (and any + * files it includes). The resulting pxe_menu struct can be free()'d by using + * the destroy_pxe_menu() function. + */ +static struct pxe_menu *parse_pxefile(char *menucfg) +{ + struct pxe_menu *cfg; + + cfg = malloc(sizeof(struct pxe_menu)); + + if (!cfg) + return NULL; + + memset(cfg, 0, sizeof(struct pxe_menu)); + + INIT_LIST_HEAD(&cfg->labels); + + if (parse_pxefile_top(menucfg, cfg, 1) < 0) { + destroy_pxe_menu(cfg); + return NULL; + } + + return cfg; +} + +/* + * Converts a pxe_menu struct into a menu struct for use with U-boot's generic + * menu code. + */ +static struct menu *pxe_menu_to_menu(struct pxe_menu *cfg) +{ + struct pxe_label *label; + struct list_head *pos; + struct menu *m; + int err; + + /* + * Create a menu and add items for all the labels. + */ + m = menu_create(cfg->title, cfg->timeout, cfg->prompt, label_print); + + if (!m) + return NULL; + + list_for_each(pos, &cfg->labels) { + label = list_entry(pos, struct pxe_label, list); + + if (menu_item_add(m, label->name, label) != 1) { + menu_destroy(m); + return NULL; + } + } + + /* + * After we've created items for each label in the menu, set the + * menu's default label if one was specified. + */ + if (cfg->default_label) { + err = menu_default_set(m, cfg->default_label); + if (err != 1) { + if (err != -ENOENT) { + menu_destroy(m); + return NULL; + } + + printf("Missing default: %s\n", cfg->default_label); + } + } + + return m; +} + +/* + * Try to boot any labels we have yet to attempt to boot. + */ +static void boot_unattempted_labels(struct pxe_menu *cfg) +{ + struct list_head *pos; + struct pxe_label *label; + + list_for_each(pos, &cfg->labels) { + label = list_entry(pos, struct pxe_label, list); + + if (!label->attempted) + label_boot(label); + } +} + +/* + * Boot the system as prescribed by a pxe_menu. + * + * Use the menu system to either get the user's choice or the default, based + * on config or user input. If there is no default or user's choice, + * attempted to boot labels in the order they were given in pxe files. + * If the default or user's choice fails to boot, attempt to boot other + * labels in the order they were given in pxe files. + * + * If this function returns, there weren't any labels that successfully + * booted, or the user interrupted the menu selection via ctrl+c. + */ +static void handle_pxe_menu(struct pxe_menu *cfg) +{ + void *choice; + struct menu *m; + int err; + + m = pxe_menu_to_menu(cfg); + if (!m) + return; + + err = menu_get_choice(m, &choice); + + menu_destroy(m); + + if (err < 1) + return; + + label_boot(choice); + + boot_unattempted_labels(cfg); +} + +/* + * Boots a system using a pxe file + * + * Returns 0 on success, 1 on error. + */ +static int +do_pxe_boot(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{ + unsigned long pxefile_addr_r; + struct pxe_menu *cfg; + char *pxefile_addr_str; + + if (argc == 1) { + pxefile_addr_str = from_env("pxefile_addr_r"); + if (!pxefile_addr_str) + return 1; + + } else if (argc == 2) { + pxefile_addr_str = argv[1]; + } else { + return cmd_usage(cmdtp); + } + + if (strict_strtoul(pxefile_addr_str, 16, &pxefile_addr_r) < 0) { + printf("Invalid pxefile address: %s\n", pxefile_addr_str); + return 1; + } + + cfg = parse_pxefile((char *)(pxefile_addr_r)); + + if (cfg == NULL) { + printf("Error parsing config file\n"); + return 1; + } + + handle_pxe_menu(cfg); + + destroy_pxe_menu(cfg); + + return 0; +} + +static cmd_tbl_t cmd_pxe_sub[] = { + U_BOOT_CMD_MKENT(get, 1, 1, do_pxe_get, "", ""), + U_BOOT_CMD_MKENT(boot, 2, 1, do_pxe_boot, "", "") +}; + +int do_pxe(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) +{ + cmd_tbl_t *cp; + + if (argc < 2) + return cmd_usage(cmdtp); + + /* drop initial "pxe" arg */ + argc--; + argv++; + + cp = find_cmd_tbl(argv[0], cmd_pxe_sub, ARRAY_SIZE(cmd_pxe_sub)); + + if (cp) + return cp->cmd(cmdtp, flag, argc, argv); + + return cmd_usage(cmdtp); +} + +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\npxe " + "boot [pxefile_addr_r] - boot from the pxe file at pxefile_addr_r\n" +); |