From a3d70a3d2b5c052db039d097aaffa42008da24b5 Mon Sep 17 00:00:00 2001 From: "J. Richard Barnette" Date: Wed, 30 Oct 2013 11:36:45 -0700 Subject: Make crossystem.h more polite and more useful. This adds a VB_MAX_STRING_PROPERTY for callers that don't want to guess at how big to make their buffers. Additionally, it changes the size parameter to VbGetPropertyString() from int to size_t. BUG=None TEST=compile the code BRANCH=none Change-Id: I22809d48e13b535593cb22a56444e2dcb27791a5 Reviewed-on: https://chromium-review.googlesource.com/175039 Reviewed-by: Randall Spangler Tested-by: Richard Barnette Reviewed-by: Bill Richardson Commit-Queue: Richard Barnette --- host/arch/arm/lib/crossystem_arch.c | 4 +++- host/arch/x86/lib/crossystem_arch.c | 4 +++- host/include/crossystem.h | 15 ++++++++++++++- host/lib/crossystem.c | 6 ++++-- host/lib/include/crossystem_arch.h | 4 +++- utility/crossystem.c | 9 +++------ 6 files changed, 30 insertions(+), 12 deletions(-) diff --git a/host/arch/arm/lib/crossystem_arch.c b/host/arch/arm/lib/crossystem_arch.c index 99b86897..b5422dec 100644 --- a/host/arch/arm/lib/crossystem_arch.c +++ b/host/arch/arm/lib/crossystem_arch.c @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -533,7 +534,8 @@ int VbGetArchPropertyInt(const char* name) { return -1; } -const char* VbGetArchPropertyString(const char* name, char* dest, int size) { +const char* VbGetArchPropertyString(const char* name, char* dest, + size_t size) { char *str = NULL; char *rv = NULL; char *prop = NULL; diff --git a/host/arch/x86/lib/crossystem_arch.c b/host/arch/x86/lib/crossystem_arch.c index 9398a35a..2b379a71 100644 --- a/host/arch/x86/lib/crossystem_arch.c +++ b/host/arch/x86/lib/crossystem_arch.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -671,7 +672,8 @@ int VbGetArchPropertyInt(const char* name) { } -const char* VbGetArchPropertyString(const char* name, char* dest, int size) { +const char* VbGetArchPropertyString(const char* name, char* dest, + size_t size) { if (!strcasecmp(name,"arch")) { return StrCopy(dest, "x86", size); diff --git a/host/include/crossystem.h b/host/include/crossystem.h index c116b0c2..25b9cc0b 100644 --- a/host/include/crossystem.h +++ b/host/include/crossystem.h @@ -10,6 +10,12 @@ extern "C" { #endif +#include + +/* Recommended size for string property buffers used with + * VbGetSystemPropertyString(). */ +#define VB_MAX_STRING_PROPERTY ((size_t) 8192) + /* Reads a system property integer. * * Returns the property value, or -1 if error. */ @@ -19,8 +25,12 @@ int VbGetSystemPropertyInt(const char* name); * specified size. Returned string will be null-terminated. If the * buffer is too small, the returned string will be truncated. * + * The caller can expect an un-truncated value if the size provided is + * at least VB_MAX_STRING_PROPERTY. + * * Returns the passed buffer, or NULL if error. */ -const char* VbGetSystemPropertyString(const char* name, char* dest, int size); +const char* VbGetSystemPropertyString(const char* name, char* dest, + size_t size); /* Sets a system property integer. * @@ -28,6 +38,9 @@ const char* VbGetSystemPropertyString(const char* name, char* dest, int size); int VbSetSystemPropertyInt(const char* name, int value); /* Set a system property string. + * + * The maximum length of the value accepted depends on the specific + * property, not on VB_MAX_STRING_PROPERTY. * * Returns 0 if success, -1 if error. */ int VbSetSystemPropertyString(const char* name, const char* value); diff --git a/host/lib/crossystem.c b/host/lib/crossystem.c index b4824332..b4962591 100644 --- a/host/lib/crossystem.c +++ b/host/lib/crossystem.c @@ -3,6 +3,7 @@ * found in the LICENSE file. */ +#include #include #include #include @@ -69,7 +70,7 @@ typedef enum VbBuildOption { /* Return true if the FWID starts with the specified string. */ int FwidStartsWith(const char *start) { - char fwid[128]; + char fwid[VB_MAX_STRING_PROPERTY]; if (!VbGetSystemPropertyString("fwid", fwid, sizeof(fwid))) return 0; @@ -492,7 +493,8 @@ int VbGetSystemPropertyInt(const char* name) { } -const char* VbGetSystemPropertyString(const char* name, char* dest, int size) { +const char* VbGetSystemPropertyString(const char* name, char* dest, + size_t size) { static const char unknown_string[] = "unknown"; /* Check architecture-dependent properties first */ diff --git a/host/lib/include/crossystem_arch.h b/host/lib/include/crossystem_arch.h index 4044c749..50198b07 100644 --- a/host/lib/include/crossystem_arch.h +++ b/host/lib/include/crossystem_arch.h @@ -8,6 +8,8 @@ #ifndef VBOOT_REFERENCE_CROSSYSTEM_ARCH_H_ #define VBOOT_REFERENCE_CROSSYSTEM_ARCH_H_ +#include + #include "vboot_nvstorage.h" #include "vboot_struct.h" @@ -76,7 +78,7 @@ int VbGetArchPropertyInt(const char* name); * will be truncated. * * Returns the passed buffer, or NULL if error. */ -const char* VbGetArchPropertyString(const char* name, char* dest, int size); +const char* VbGetArchPropertyString(const char* name, char* dest, size_t size); /* Set an architecture-specific system property integer. * diff --git a/utility/crossystem.c b/utility/crossystem.c index d7007eeb..520f7fdf 100644 --- a/utility/crossystem.c +++ b/utility/crossystem.c @@ -11,9 +11,6 @@ #include "crossystem.h" -/* Max length of a string parameter */ -#define MAX_STRING 8192 - /* * Call arch specific init, if provided, otherwise use the 'weak' stub. */ @@ -153,7 +150,7 @@ int SetParam(const Param* p, const char* value) { * Returns 0 if success (match), non-zero if error (mismatch). */ int CheckParam(const Param* p, char* expect) { if (p->flags & IS_STRING) { - char buf[MAX_STRING]; + char buf[VB_MAX_STRING_PROPERTY]; const char* v = VbGetSystemPropertyString(p->name, buf, sizeof(buf)); if (!v || 0 != strcmp(v, expect)) return 1; @@ -175,7 +172,7 @@ int CheckParam(const Param* p, char* expect) { * Returns 0 if success, non-zero if error. */ int PrintParam(const Param* p) { if (p->flags & IS_STRING) { - char buf[MAX_STRING]; + char buf[VB_MAX_STRING_PROPERTY]; const char* v = VbGetSystemPropertyString(p->name, buf, sizeof(buf)); if (!v) return 1; @@ -197,7 +194,7 @@ int PrintParam(const Param* p) { int PrintAllParams(int force_all) { const Param* p; int retval = 0; - char buf[MAX_STRING]; + char buf[VB_MAX_STRING_PROPERTY]; const char* value; for (p = sys_param_list; p->name; p++) { -- cgit v1.2.1