annotate objgrep/lowlevel.c @ 268:e493fcff28ab

cinitdump program written, compiles
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 19 Jan 2018 06:19:59 +0000
parents c25367bb7656
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
74
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
1 /*
167
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
2 * This C module implements the low-level steps of file mapping and access.
74
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
3 */
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
4
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
5 #include <sys/types.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
6 #include <sys/file.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
7 #include <sys/stat.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
8 #include <sys/mman.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
9 #include <stdio.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
10 #include <stdlib.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
11 #include <unistd.h>
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
12 #include "globals.h"
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
13
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
14 mmap_objfile()
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
15 {
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
16 int fd;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
17 struct stat st;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
18
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
19 fd = open(objfilename, O_RDONLY);
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
20 if (fd < 0) {
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
21 perror(objfilename);
167
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
22 exit(2);
74
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
23 }
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
24 fstat(fd, &st);
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
25 if (!S_ISREG(st.st_mode)) {
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
26 fprintf(stderr, "error: %s is not a regular file\n",
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
27 objfilename);
167
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
28 exit(2);
74
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
29 }
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
30 objfile_tot_size = st.st_size;
167
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
31 objfilemap = mmap(NULL, objfile_tot_size, PROT_READ, MAP_PRIVATE,
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
32 fd, 0L);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
33 if (objfilemap == MAP_FAILED) {
74
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
34 perror("mmap");
167
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
35 exit(2);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
36 }
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
37 close(fd);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
38 }
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
39
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
40 mmap_binfile()
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
41 {
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
42 int fd;
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
43 struct stat st;
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
44
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
45 fd = open(binfilename, O_RDONLY);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
46 if (fd < 0) {
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
47 perror(binfilename);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
48 exit(2);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
49 }
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
50 fstat(fd, &st);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
51 if (!S_ISREG(st.st_mode)) {
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
52 fprintf(stderr, "error: %s is not a regular file\n",
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
53 binfilename);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
54 exit(2);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
55 }
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
56 binfile_tot_size = st.st_size;
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
57 binfilemap = mmap(NULL, binfile_tot_size, PROT_READ, MAP_PRIVATE,
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
58 fd, 0L);
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
59 if (binfilemap == MAP_FAILED) {
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
60 perror("mmap");
c25367bb7656 objgrep: written, compiles
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents: 130
diff changeset
61 exit(2);
74
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
62 }
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
63 close(fd);
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
64 }
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
65
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
66 unsigned
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
67 get_u16(ptr)
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
68 u_char *ptr;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
69 {
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
70 return ptr[0] | ptr[1] << 8;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
71 }
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
72
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
73 get_s16(ptr)
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
74 u_char *ptr;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
75 {
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
76 int i;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
77
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
78 i = ptr[0] | ptr[1] << 8;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
79 if (i >= 32768)
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
80 i -= 65536;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
81 return(i);
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
82 }
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
83
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
84 unsigned
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
85 get_u32(ptr)
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
86 u_char *ptr;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
87 {
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
88 return ptr[0] | ptr[1] << 8 | ptr[2] << 16 | ptr[3] << 24;
2eef88395908 tiobjd: a little refactoring
Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
parents:
diff changeset
89 }