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boot: Move PXE-parsing logic out to a separate file

Browse Source 
The pxe_utils.c file is quite large and has a mix of parsing and booting
code. Split out the parsing into a new 'pxe_parse.c' file.

Add function prototypes for parse_pxefile_top() and label_destroy(), the
two functions used by pxe_utils.c

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass
2025-07-30 13:52:43 +12:00
parent 70fa14e7fa
commit 4c423e6711
4 changed files with 717 additions and 705 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
boot/Makefile
View File

@@ -8,7 +8,7 @@ ifndef CONFIG_XPL_BUILD
obj-$(CONFIG_BOOT_RETRY) += bootretry.o
obj-$(CONFIG_BOOT) += bootm.o bootm_os.o
obj-$(CONFIG_PXE_UTILS) += pxe_utils.o
obj-$(CONFIG_PXE_UTILS) += pxe_utils.o pxe_parse.o
endif

692
boot/pxe_parse.c Normal file
View File

@@ -0,0 +1,692 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2010-2011 Calxeda, Inc.
* Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
*/
#define LOG_CATEGORY LOGC_BOOT
#include <ctype.h>
#include <malloc.h>
#include <mapmem.h>
#include "pxe_utils.h"
/** enum token_type - 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_LINUX,
T_APPEND,
T_INITRD,
T_LOCALBOOT,
T_DEFAULT,
T_PROMPT,
T_INCLUDE,
T_FDT,
T_FDTDIR,
T_FDTOVERLAYS,
T_ONTIMEOUT,
T_IPAPPEND,
T_BACKGROUND,
T_KASLRSEED,
T_FALLBACK,
T_SAY,
T_INVALID
};
/** struct token - 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},
{"linux", T_LINUX},
{"localboot", T_LOCALBOOT},
{"append", T_APPEND},
{"initrd", T_INITRD},
{"include", T_INCLUDE},
{"devicetree", T_FDT},
{"fdt", T_FDT},
{"devicetreedir", T_FDTDIR},
{"fdtdir", T_FDTDIR},
{"fdtoverlays", T_FDTOVERLAYS},
{"devicetree-overlay", T_FDTOVERLAYS},
{"ontimeout", T_ONTIMEOUT,},
{"ipappend", T_IPAPPEND,},
{"background", T_BACKGROUND,},
{"kaslrseed", T_KASLRSEED,},
{"fallback", T_FALLBACK,},
{"say", T_SAY,},
{NULL, T_INVALID}
};
/**
* enum lex_state - lexer state
*
* 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
};
/**
* label_create() - crate a new PXE label
*
* Allocates memory for and initializes a pxe_label. This uses malloc, so the
* result must be free()'d to reclaim the memory.
*
* Returns a pointer to the label, or NULL if out of memory
*/
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;
}
void label_destroy(struct pxe_label *label)
{
free(label->name);
free(label->kernel_label);
free(label->kernel);
free(label->config);
free(label->append);
free(label->initrd);
free(label->fdt);
free(label->fdtdir);
free(label->fdtoverlays);
free(label);
}
/**
* get_string() - retrieves a string from *p and stores it as a token in *t.
*
* This is 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.
*
* Memory for t->val is allocated using malloc and must be free()'d to reclaim
* it.
*
* @p: Points to a pointer to the current position in the input being processed.
* Updated to point at the first character after the current token
* @t: Pointers to a token to fill in
* @delim: Delimiter character to look for, either newline or space
* @lower: true to convert the string to lower case when storing
* Returns the new value of t->val, on success, NULL if out of memory
*/
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 = *p;
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;
}
/**
* get_keyword() - Populate a keyword token with a type and value
*
* Updates the ->type field based on the keyword string in @val
* @t: Token to populate
*/
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_token() - 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: Points to a pointer to the current position in the input being processed.
* 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;
}
/**
* eol_or_eof() - Find end of line
*
* Increment *c until we get to the end of the current line, or EOF
*
* @c: Points to a pointer to the current position in the input being processed.
* Updated to point at the first character after the current token
*/
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;
get_token(c, &t, L_SLITERAL);
if (t.type != T_STRING) {
printf("Expected string: %.*s\n", (int)(*c - s), s);
return -EINVAL;
}
*dst = simple_strtol(t.val, NULL, 10);
free(t.val);
return 1;
}
/*
* 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(struct pxe_context *ctx, char **c, unsigned long base,
struct pxe_menu *cfg, int nest_level)
{
char *include_path;
char *s = *c;
int err;
char *buf;
int ret;
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(ctx, include_path, base);
if (err < 0) {
printf("Couldn't retrieve %s\n", include_path);
return err;
}
buf = map_sysmem(base, 0);
ret = parse_pxefile_top(ctx, buf, base, cfg, nest_level);
unmap_sysmem(buf);
return ret;
}
/*
* Parse lines that begin with 'menu'.
*
* base and nest are provided to handle the 'menu include' case.
*
* base should point to a location where it's safe to store the included file.
*
* 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(struct pxe_context *ctx, char **c, struct pxe_menu *cfg,
unsigned long base, int nest_level)
{
struct token t;
char *s = *c;
int err = 0;
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(ctx, c, base, cfg, nest_level + 1);
break;
case T_BACKGROUND:
err = parse_sliteral(c, &cfg->bmp);
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)
cfg->default_label = strdup(label->name);
if (!cfg->default_label)
return -ENOMEM;
break;
case T_LABEL:
parse_sliteral(c, &label->menu);
break;
default:
printf("Ignoring malformed menu command: %.*s\n",
(int)(*c - s), s);
}
eol_or_eof(c);
return 0;
}
/*
* Handles parsing a 'kernel' label.
* expecting "filename" or "<fit_filename>#cfg"
*/
static int parse_label_kernel(char **c, struct pxe_label *label)
{
char *s;
int err;
err = parse_sliteral(c, &label->kernel);
if (err < 0)
return err;
/* copy the kernel label to compare with FDT / INITRD when FIT is used */
label->kernel_label = strdup(label->kernel);
if (!label->kernel_label)
return -ENOMEM;
s = strstr(label->kernel, "#");
if (!s)
return 1;
label->config = strdup(s);
if (!label->config)
return -ENOMEM;
*s = 0;
return 1;
}
/*
* 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;
int len;
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:
case T_LINUX:
err = parse_label_kernel(c, label);
break;
case T_APPEND:
err = parse_sliteral(c, &label->append);
if (label->initrd)
break;
s = strstr(label->append, "initrd=");
if (!s)
break;
s += 7;
len = (int)(strchr(s, ' ') - s);
label->initrd = malloc(len + 1);
strlcpy(label->initrd, s, len);
label->initrd[len] = '\0';
break;
case T_INITRD:
if (!label->initrd)
err = parse_sliteral(c, &label->initrd);
break;
case T_FDT:
if (!label->fdt)
err = parse_sliteral(c, &label->fdt);
break;
case T_FDTDIR:
if (!label->fdtdir)
err = parse_sliteral(c, &label->fdtdir);
break;
case T_FDTOVERLAYS:
if (!label->fdtoverlays)
err = parse_sliteral(c, &label->fdtoverlays);
break;
case T_LOCALBOOT:
label->localboot = 1;
err = parse_integer(c, &label->localboot_val);
break;
case T_IPAPPEND:
err = parse_integer(c, &label->ipappend);
break;
case T_KASLRSEED:
label->kaslrseed = 1;
break;
case T_EOL:
break;
case T_SAY: {
char *p = strchr(s, '\n');
if (p) {
printf("%.*s\n", (int)(p - *c) - 1, *c + 1);
*c = p;
}
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
int parse_pxefile_top(struct pxe_context *ctx, char *p, ulong base,
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:
cfg->prompt = 1;
err = parse_menu(ctx, &p, cfg,
base + ALIGN(strlen(b) + 1, 4),
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:
case T_ONTIMEOUT:
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_FALLBACK:
err = parse_sliteral(&p, &label_name);
if (label_name) {
if (cfg->fallback_label)
free(cfg->fallback_label);
cfg->fallback_label = label_name;
}
break;
case T_INCLUDE:
err = handle_include(ctx, &p,
base + ALIGN(strlen(b), 4), cfg,
nest_level + 1);
break;
case T_PROMPT:
err = parse_integer(&p, &cfg->prompt);
// Do not fail if prompt configuration is undefined
if (err < 0)
eol_or_eof(&p);
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;
}
}

704
boot/pxe_utils.c
View File

@@ -216,54 +216,6 @@ static int get_relfile_envaddr(struct pxe_context *ctx, const char *file_path,
return get_relfile(ctx, file_path, file_addr, type, filesizep);
}
/**
* label_create() - crate a new PXE label
*
* Allocates memory for and initializes a pxe_label. This uses malloc, so the
* result must be free()'d to reclaim the memory.
*
* Returns a pointer to the label, or NULL if out of memory
*/
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;
}
/**
* label_destroy() - free the memory used by a pxe_label
*
* This frees @label itself as well as memory used by its name,
* kernel, config, append, initrd, fdt, fdtdir and fdtoverlay 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.
*
* @label: Label to free
*/
static void label_destroy(struct pxe_label *label)
{
free(label->name);
free(label->kernel_label);
free(label->kernel);
free(label->config);
free(label->append);
free(label->initrd);
free(label->fdt);
free(label->fdtdir);
free(label->fdtoverlays);
free(label);
}
/**
* label_print() - Print a label and its string members if they're defined
*
@@ -866,662 +818,6 @@ cleanup:
return 1; /* returning is always failure */
}
/** enum token_type - 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_LINUX,
T_APPEND,
T_INITRD,
T_LOCALBOOT,
T_DEFAULT,
T_PROMPT,
T_INCLUDE,
T_FDT,
T_FDTDIR,
T_FDTOVERLAYS,
T_ONTIMEOUT,
T_IPAPPEND,
T_BACKGROUND,
T_KASLRSEED,
T_FALLBACK,
T_SAY,
T_INVALID
};
/** struct token - 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},
{"linux", T_LINUX},
{"localboot", T_LOCALBOOT},
{"append", T_APPEND},
{"initrd", T_INITRD},
{"include", T_INCLUDE},
{"devicetree", T_FDT},
{"fdt", T_FDT},
{"devicetreedir", T_FDTDIR},
{"fdtdir", T_FDTDIR},
{"fdtoverlays", T_FDTOVERLAYS},
{"devicetree-overlay", T_FDTOVERLAYS},
{"ontimeout", T_ONTIMEOUT,},
{"ipappend", T_IPAPPEND,},
{"background", T_BACKGROUND,},
{"kaslrseed", T_KASLRSEED,},
{"fallback", T_FALLBACK,},
{"say", T_SAY,},
{NULL, T_INVALID}
};
/**
* enum lex_state - lexer state
*
* 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.
*
* This is 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.
*
* Memory for t->val is allocated using malloc and must be free()'d to reclaim
* it.
*
* @p: Points to a pointer to the current position in the input being processed.
* Updated to point at the first character after the current token
* @t: Pointers to a token to fill in
* @delim: Delimiter character to look for, either newline or space
* @lower: true to convert the string to lower case when storing
* Returns the new value of t->val, on success, NULL if out of memory
*/
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 = *p;
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;
}
/**
* get_keyword() - Populate a keyword token with a type and value
*
* Updates the ->type field based on the keyword string in @val
* @t: Token to populate
*/
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_token() - 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: Points to a pointer to the current position in the input being processed.
* 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;
}
/**
* eol_or_eof() - Find end of line
*
* Increment *c until we get to the end of the current line, or EOF
*
* @c: Points to a pointer to the current position in the input being processed.
* Updated to point at the first character after the current token
*/
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;
get_token(c, &t, L_SLITERAL);
if (t.type != T_STRING) {
printf("Expected string: %.*s\n", (int)(*c - s), s);
return -EINVAL;
}
*dst = simple_strtol(t.val, NULL, 10);
free(t.val);
return 1;
}
static int parse_pxefile_top(struct pxe_context *ctx, char *p, ulong base,
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(struct pxe_context *ctx, char **c, unsigned long base,
struct pxe_menu *cfg, int nest_level)
{
char *include_path;
char *s = *c;
int err;
char *buf;
int ret;
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(ctx, include_path, base);
if (err < 0) {
printf("Couldn't retrieve %s\n", include_path);
return err;
}
buf = map_sysmem(base, 0);
ret = parse_pxefile_top(ctx, buf, base, cfg, nest_level);
unmap_sysmem(buf);
return ret;
}
/*
* Parse lines that begin with 'menu'.
*
* base and nest are provided to handle the 'menu include' case.
*
* base should point to a location where it's safe to store the included file.
*
* 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(struct pxe_context *ctx, char **c, struct pxe_menu *cfg,
unsigned long base, int nest_level)
{
struct token t;
char *s = *c;
int err = 0;
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(ctx, c, base, cfg, nest_level + 1);
break;
case T_BACKGROUND:
err = parse_sliteral(c, &cfg->bmp);
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)
cfg->default_label = strdup(label->name);
if (!cfg->default_label)
return -ENOMEM;
break;
case T_LABEL:
parse_sliteral(c, &label->menu);
break;
default:
printf("Ignoring malformed menu command: %.*s\n",
(int)(*c - s), s);
}
eol_or_eof(c);
return 0;
}
/*
* Handles parsing a 'kernel' label.
* expecting "filename" or "<fit_filename>#cfg"
*/
static int parse_label_kernel(char **c, struct pxe_label *label)
{
char *s;
int err;
err = parse_sliteral(c, &label->kernel);
if (err < 0)
return err;
/* copy the kernel label to compare with FDT / INITRD when FIT is used */
label->kernel_label = strdup(label->kernel);
if (!label->kernel_label)
return -ENOMEM;
s = strstr(label->kernel, "#");
if (!s)
return 1;
label->config = strdup(s);
if (!label->config)
return -ENOMEM;
*s = 0;
return 1;
}
/*
* 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;
int len;
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:
case T_LINUX:
err = parse_label_kernel(c, label);
break;
case T_APPEND:
err = parse_sliteral(c, &label->append);
if (label->initrd)
break;
s = strstr(label->append, "initrd=");
if (!s)
break;
s += 7;
len = (int)(strchr(s, ' ') - s);
label->initrd = malloc(len + 1);
strncpy(label->initrd, s, len);
label->initrd[len] = '\0';
break;
case T_INITRD:
if (!label->initrd)
err = parse_sliteral(c, &label->initrd);
break;
case T_FDT:
if (!label->fdt)
err = parse_sliteral(c, &label->fdt);
break;
case T_FDTDIR:
if (!label->fdtdir)
err = parse_sliteral(c, &label->fdtdir);
break;
case T_FDTOVERLAYS:
if (!label->fdtoverlays)
err = parse_sliteral(c, &label->fdtoverlays);
break;
case T_LOCALBOOT:
label->localboot = 1;
err = parse_integer(c, &label->localboot_val);
break;
case T_IPAPPEND:
err = parse_integer(c, &label->ipappend);
break;
case T_KASLRSEED:
label->kaslrseed = 1;
break;
case T_EOL:
break;
case T_SAY: {
char *p = strchr(s, '\n');
if (p) {
printf("%.*s\n", (int)(p - *c) - 1, *c + 1);
*c = p;
}
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(struct pxe_context *ctx, char *p, unsigned long base,
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:
cfg->prompt = 1;
err = parse_menu(ctx, &p, cfg,
base + ALIGN(strlen(b) + 1, 4),
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:
case T_ONTIMEOUT:
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_FALLBACK:
err = parse_sliteral(&p, &label_name);
if (label_name) {
if (cfg->fallback_label)
free(cfg->fallback_label);
cfg->fallback_label = label_name;
}
break;
case T_INCLUDE:
err = handle_include(ctx, &p,
base + ALIGN(strlen(b), 4), cfg,
nest_level + 1);
break;
case T_PROMPT:
err = parse_integer(&p, &cfg->prompt);
// Do not fail if prompt configuration is undefined
if (err < 0)
eol_or_eof(&p);
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;
}
}
/*
*/
void destroy_pxe_menu(struct pxe_menu *cfg)

24
include/pxe_utils.h
View File

@@ -324,4 +324,28 @@ int pxe_probe(struct pxe_context *ctx, ulong pxefile_addr_r, bool prompt);
*/
int pxe_do_boot(struct pxe_context *ctx);
/*
* 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.
*/
int parse_pxefile_top(struct pxe_context *ctx, char *p, ulong base,
struct pxe_menu *cfg, int nest_level);
/**
* label_destroy() - free the memory used by a pxe_label
*
* This frees @label itself as well as memory used by its name,
* kernel, config, append, initrd, fdt, fdtdir and fdtoverlay 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.
*
* @label: Label to free
*/
void label_destroy(struct pxe_label *label);
#endif /* __PXE_UTILS_H */