SecurityTests/cspxutils/utilLib/fileIo.c

   1 #include <unistd.h>
   2 #include <fcntl.h>
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include "fileIo.h"
   9
  10 int cspWriteFile(
  11         const char                      *fileName,
  12         const unsigned char     *bytes,
  13         unsigned                        numBytes)
  14 {
  15         int             rtn;
  16         int     fd;
  17
  18         fd = open(fileName, O_RDWR | O_CREAT | O_TRUNC, 0600);
  19         if(fd <= 0) {
  20                 return errno;
  21         }
  22         rtn = lseek(fd, 0, SEEK_SET);
  23         if(rtn < 0) {
  24                 return errno;
  25         }
  26         rtn = write(fd, bytes, (size_t)numBytes);
  27         if(rtn != (int)numBytes) {
  28                 if(rtn >= 0) {
  29                         printf("writeFile: short write\n");
  30                 }
  31                 rtn = EIO;
  32         }
  33         else {
  34                 rtn = 0;
  35         }
  36         close(fd);
  37         return rtn;
  38 }
  39
  40 /*
  41  * Read entire file.
  42  */
  43 int cspReadFile(
  44         const char              *fileName,
  45         unsigned char   **bytes,                // mallocd and returned
  46         unsigned                *numBytes)              // returned
  47 {
  48         int ourRtn = 0;
  49         int fd;
  50         char *buf;
  51         char *thisBuf;
  52         struct stat     sb;
  53         unsigned size;
  54         size_t toMove;
  55         ssize_t thisMoved;
  56         int irtn;
  57         off_t lrtn = 0;
  58
  59         *numBytes = 0;
  60         *bytes = NULL;
  61         fd = open(fileName, O_RDONLY, 0);
  62         if(fd <= 0) {
  63                 perror("open");
  64                 return errno;
  65         }
  66         irtn = fstat(fd, &sb);
  67         if(irtn) {
  68                 ourRtn = errno;
  69                 if(ourRtn == 0) {
  70                         fprintf(stderr, "***Bogus zero error on fstat\n");
  71                         ourRtn = -1;
  72                 }
  73                 else {
  74                         perror("fstat");
  75                 }
  76                 goto errOut;
  77         }
  78         size = sb.st_size;
  79         buf = thisBuf = (char *)malloc(size);
  80         if(buf == NULL) {
  81                 ourRtn = ENOMEM;
  82                 goto errOut;
  83         }
  84         lrtn = lseek(fd, 0, SEEK_SET);
  85         if(lrtn < 0) {
  86                 ourRtn = errno;
  87                 if(ourRtn == 0) {
  88                         fprintf(stderr, "***Bogus zero error on lseek\n");
  89                         ourRtn = -1;
  90                 }
  91                 else {
  92                         perror("lseek");
  93                 }
  94                 goto errOut;
  95         }
  96         toMove = size;
  97
  98         /*
  99          * On ppc this read ALWAYS returns the entire file. On i386, not so.
 100          */
 101         do {
 102                 thisMoved = read(fd, thisBuf, toMove);
 103                 if(thisMoved == 0) {
 104                         /* reading empty file: done */
 105                         break;
 106                 }
 107                 else if(thisMoved < 0) {
 108                         ourRtn = errno;
 109                         perror("read");
 110                         break;
 111                 }
 112                 size_t uThisMoved = (size_t)thisMoved;
 113                 if(uThisMoved != toMove) {
 114                         fprintf(stderr, "===Short read: asked for %ld, got %lu\n",
 115                                 toMove, uThisMoved);
 116                 }
 117                 toMove  -= thisMoved;
 118                 thisBuf += thisMoved;
 119         } while(toMove);
 120
 121         if(ourRtn == 0) {
 122                 *bytes = (unsigned char *)buf;
 123                 *numBytes = size;
 124         }
 125 errOut:
 126         close(fd);
 127         return ourRtn;
 128 }