X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=include%2Flibelfu%2Ftypes.h;fp=include%2Flibelfu%2Ftypes.h;h=c1fbfda217da10e155d6cd2b451360f6a4b85016;hb=50b85e44529f195bf8156e9c0045d8b017ee26f5;hp=d6a758459d5add55a53899151508964b69f6e375;hpb=28507233568a6deb80e243bd82df1e93f0b136a0;p=centaur.git

diff --git a/include/libelfu/types.h b/include/libelfu/types.h
index d6a7584..c1fbfda 100644
--- a/include/libelfu/types.h
+++ b/include/libelfu/types.h
@@ -1,3 +1,12 @@
+/*!
+ * @file types.h
+ * @brief libelfu's Elfu* types.
+ *
+ * libelfu provides an abstraction of the data in ELF files
+ * to more closely model the dependencies between them, and
+ * thus to facilitate consistent editing.
+ */
+
 #ifndef __LIBELFU_TYPES_H__
 #define __LIBELFU_TYPES_H__
 
@@ -7,46 +16,90 @@
 #include <gelf.h>
 
 
+/*!
+ * ELFU model of a symbol table entry.
+ */
 typedef struct ElfuSym {
+  /*! Offset into linked string table */
   GElf_Word name;
 
+
+  /*! Explicit value */
   GElf_Addr value;
+
+  /*! Size of object referenced */
   GElf_Word size;
 
+
+  /*! Binding type (GLOBAL, LOCAL, ...) */
   unsigned char bind;
+
+  /*! Type (FUNC, SECTION, ...) */
   unsigned char type;
+
+  /*! Always 0, currently meaningless (see ELF spec) */
   unsigned char other;
 
+
+  /*! If non-null, the section referenced. */
   struct ElfuScn *scnptr;
+
+  /*! If scnptr is invalid, then this is ABS, COMMON, or UNDEF. */
   int shndx;
 
+
+  /*! Entry in a symbol table */
   CIRCLEQ_ENTRY(ElfuSym) elem;
 } ElfuSym;
 
 
+
+/*!
+ * ELFU model of a symbol table.
+ */
 typedef struct ElfuSymtab {
+  /*! All parsed symbols */
   CIRCLEQ_HEAD(Syms, ElfuSym) syms;
 } ElfuSymtab;
 
 
 
-typedef struct ElfuRel {
-  char *name;
 
+
+/*!
+ * ELFU model of a relocation entry.
+ */
+typedef struct ElfuRel {
+  /*! Location to patch */
   GElf_Addr offset;
-  GElf_Word info;
 
+
+  /*! Symbol to calculate value for */
   GElf_Word sym;
+
+  /*! Relocation type (machine specific) */
   unsigned char type;
 
+
+  /*! addendUsed == 0: Use addend from relocation destination (REL).
+   *  addendUsed != 0: Use explicit addend (RELA). */
   int addendUsed;
+
+  /*! Explicit addend in RELA tables */
   GElf_Sword addend;
 
+
+  /*! Element in table */
   CIRCLEQ_ENTRY(ElfuRel) elem;
 } ElfuRel;
 
 
+
+/*!
+ * ELFU model of a relocation table.
+ */
 typedef struct ElfuReltab {
+  /*! All parsed relocation entries */
   CIRCLEQ_HEAD(Rels, ElfuRel) rels;
 } ElfuReltab;
 
@@ -55,42 +108,105 @@ typedef struct ElfuReltab {
 
 
 
+
+/*!
+ * ELFU model of an ELF section.
+ *
+ * Several members of the SHDR are repeated in abstract form and take
+ * precedence if present. For example, if linkptr is non-NULL then
+ * it points to another section and the SHDR's numeric sh_link member
+ * is to be ignored and recomputed by the layouter.
+ */
 typedef struct ElfuScn {
+  /*! SHDR as per ELF specification.
+   *  Several values are ignored or recomputed from other members of
+   *  ElfuScn. */
   GElf_Shdr shdr;
 
+  /*! malloc()ed buffer containing this section's flat data backbuffer.
+   *  Present for all sections that occupy space in the file. */
+  char *databuf;
+
+
+  /*! Pointer to a section, meaning dependent on sh_type.
+   *  Preferred over sh_link if non-null. */
   struct ElfuScn *linkptr;
+
+  /*! Pointer to a section, meaning dependent on sh_type.
+   *  Preferred over sh_info if non-null. */
   struct ElfuScn *infoptr;
-  char *databuf;
 
+
+  /*! If this section is a clone of another section, then this
+   *  points to that other section.
+   *  Used during code injection to facilitate relocation. */
   struct ElfuScn *oldptr;
 
+
+  /*! Translated contents of a symbol table. */
   struct ElfuSymtab symtab;
+
+  /*! Translated contents of a relocation table. */
   struct ElfuReltab reltab;
 
+
+  /*! Element linking this section into an ElfuPhdr's childScnList,
+   *  or into an ElfuElf's orphanScnList. */
   CIRCLEQ_ENTRY(ElfuScn) elemChildScn;
 } ElfuScn;
 
 
+
+/*!
+ * ELFU model of an ELF PHDR.
+ */
 typedef struct ElfuPhdr {
+  /*! PHDR as per ELF specification. */
   GElf_Phdr phdr;
 
+
+  /*! Sections to be shifted in file/memory together with this PHDR */
   CIRCLEQ_HEAD(ChildScnList, ElfuScn) childScnList;
+
+  /*! PHDRs to be shifted in file/memory together with this PHDR */
   CIRCLEQ_HEAD(ChildPhdrList, ElfuPhdr) childPhdrList;
 
+
+  /*! Element linking this section into an ElfuPhdr's childPhdrList */
   CIRCLEQ_ENTRY(ElfuPhdr) elemChildPhdr;
+
+  /*! Element linking this section into an ElfuElf's phdrList */
   CIRCLEQ_ENTRY(ElfuPhdr) elem;
 } ElfuPhdr;
 
 
+
+/*!
+ * ELFU model of an ELF file header
+ */
 typedef struct {
+  /*! The ELF class -- ELFCLASS32/ELFCLASS64 */
   int elfclass;
+
+  /*! EHDR as per ELF specification */
   GElf_Ehdr ehdr;
 
+
+  /*! PHDRs that are not dependent on others.
+   *  Usually, LOAD and GNU_STACK. */
   CIRCLEQ_HEAD(PhdrList, ElfuPhdr) phdrList;
+
+  /*! Sections not in any PHDR, and thus not loaded at runtime.
+   *  Usually .symtab, .strtab, .shstrtab, .debug_*, ... */
   CIRCLEQ_HEAD(OrphanScnList, ElfuScn) orphanScnList;
 
+
+  /*! Pointer to ElfuScn containing .shstrtab.
+   *  Parsed from EHDR for convenience. */
   ElfuScn *shstrtab;
 
+  /*! Pointer to ElfuScn containing .symtab.
+   *  Parsed from list of sections for convenience. */
   ElfuScn *symtab;
 } ElfuElf;