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#include "format.h"
#include "gzip.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
struct segment empty_segment = {
.start = -1,
.end = -1,
.description = "No segment selected",
};
struct segment get_segment(void *mem, size_t len, ssize_t addr) {
if (addr < 0 || addr >= len) {
return empty_segment;
}
static char *buf = NULL;
if (buf != NULL) {
free(buf);
buf = NULL;
}
struct member *header = (struct member*) mem;
if (addr == 0) {
return (struct segment) {
.start = 0,
.end = 1,
.description = "ID1 = 31"
};
}
if (addr == 1) {
return (struct segment) {
.start = 1,
.end = 2,
.description = "ID2 = 139",
};
}
if (addr == 2) {
return (struct segment) {
.start = 2,
.end = 3,
.description = "CM (Compression Method)\n"
"CM = 8 is defalte",
};
}
if (addr == 3) {
buf = malloc(1000);
buf[0] = '\0';
for (int i = 0; i < 5; i++) {
if (header->flg & (1 << i)) {
strcat(buf, "- ");
strcat(buf, flag_str(1<<i));
strcat(buf, "\n");
}
}
return (struct segment) {
.start = 3,
.end = 4,
.description = buf,
};
}
if (addr >= 4 && addr < 8) {
buf = malloc(1000);
sprintf(buf, "Mtime=%i", header->mtime);
return (struct segment) {
.start = 4,
.end = 8,
.description = buf,
};
}
if (addr == 8) {
return (struct segment) {
.start = 8,
.end = 9,
.description = "XFL",
};
}
if (addr == 9) {
buf = malloc(1000);
sprintf(buf, "OS: %s\n", os_str(header->os));
return (struct segment) {
.start = 9,
.end = 10,
.description = buf,
};
}
void *ptr = ((struct member*) mem) + 1;
if (header->flg & FEXTRA) {
uint16_t xlen = *((uint16_t*) ptr);
if (mem + addr == ptr || mem + addr == ptr + 1) {
return (struct segment) {
.start = ptr - mem,
.end = ptr - mem + 1,
.description = "XLEN",
};
}
ptr = ((uint16_t*) ptr) + 1;
// if (mem + addr >= ptr && mem + addr < xlen) {
if (ptr - mem + addr < 2) {
return (struct segment) {
.start = ptr - mem,
.end = ptr - mem + xlen,
.description = "XLEN bytes of extra data",
};
}
ptr = ((uint8_t*) ptr) + 1 + xlen;
}
if (header->flg & FNAME) {
void *c = memchr(ptr, '\0', (ptr - mem) + len);
size_t start = ptr - mem;
size_t end = c - mem;
ptr = ((uint8_t*) c) + 1;
if (addr < c - mem + 1) {
return (struct segment) {
.start = start,
.end = end + 1,
.description = "Original filename",
};
}
}
if (header->flg & FCOMMENT) {
void *c = memchr(ptr, '\0', (ptr - mem) + len);
ptr = ((uint8_t*) c) + 1;
if (addr < c - mem + 1) {
size_t start = ptr - mem;
size_t end = c - mem;
return (struct segment) {
.start = start,
.end = end + 1,
.description = "File comment",
};
}
}
if (header->flg & FHCRC) {
if (addr < ptr - mem + 2) {
buf = malloc(1000);
fprintf(buf, "CRC16=" PRIu16, *((uint16_t*) ptr));
return (struct segment) {
.start = ptr - mem,
.end = ptr - mem + 2,
.description = buf,
};
}
ptr = (uint16_t*) ptr + 1;
}
if (len - addr < 4) {
buf = malloc(1000);
fprintf(buf, "ISIZE" PRIu32, *(((uint32_t*) ((uint8_t*) (mem + len))) - 1));
return (struct segment) {
.start = len - 4,
.end = len,
.description = buf,
};
}
if (len - addr - 4 < 4) {
buf = malloc(1000);
fprintf(buf, "CRC32" PRIu32, *(((uint32_t*) ((uint8_t*) (mem + len))) - 2));
return (struct segment) {
.start = len - 8,
.end = len - 4,
.description = buf,
};
}
if (ptr - mem <= addr && addr < ptr - mem + len - 8) {
return (struct segment) {
.start = ptr - mem,
.end = len - 8,
.description = "ZLIB compressed payload",
};
}
return empty_segment;
}
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