solaris-fopen-sucks-20060916

[openafs.git] / src / auth / cellconfig.c

diff --git a/src/auth/cellconfig.c b/src/auth/cellconfig.c
index b20b038..a88dfd4 100644 (file)
--- a/src/auth/cellconfig.c
+++ b/src/auth/cellconfig.c
@@ -114,6 +114,113 @@ static int SaveKeys(struct afsconf_dir *adir);
  * CellServDB changes.
  */
 
+#if defined(AFS_SUN5_ENV) && !defined(__sparcv9)
+/* Solaris through 10 in 32 bit mode will return EMFILE if fopen can't
+   get an fd <= 255. We allow the fileserver to claim more fds than that.
+   This has always been a problem since pr_Initialize would have the same
+   issue, but hpr_Initialize makes it more likely that we would see this. 
+   Work around it. This is not generic. It's coded with the needs of
+   afsconf_* in mind only.
+
+   http://www.opensolaris.org/os/community/onnv/flag-days/pages/2006042001/
+*/
+
+#define BUFFER 4096
+
+struct afsconf_iobuffer {
+    int _file;
+    char *buffer;
+    char *ptr;
+    char *endptr;
+};
+
+typedef struct afsconf_iobuffer afsconf_FILE;
+
+static afsconf_FILE *
+afsconf_fopen(const char *fname, const char *fmode)
+{
+    int fd;
+    afsconf_FILE *iop;
+    
+    if ((fd = open(fname, O_RDONLY)) == -1) {
+       return NULL;
+    }
+    
+    iop = malloc(sizeof(struct afsconf_iobuffer));
+    if (iop == NULL) {
+       (void) close(fd);
+       errno = ENOMEM;
+       return NULL;
+    }
+    iop->_file = fd;
+    iop->buffer = malloc(BUFFER);
+    if (iop->buffer == NULL) {
+       (void) close(fd);
+       free((void *) iop);
+       errno = ENOMEM;
+       return NULL;
+    }
+    iop->ptr = iop->buffer;
+    iop->endptr = iop->buffer;
+    return iop;
+}
+
+static int
+afsconf_fclose(afsconf_FILE *iop)
+{
+    if (iop == NULL) {
+       return 0;
+    }
+    close(iop->_file);
+    free((void *)iop->buffer);
+    free((void *)iop);
+    return 0;
+}
+
+static char *
+afsconf_fgets(char *s, int n, afsconf_FILE *iop)
+{
+    char *p;
+    
+    p = s;
+    for (;;) {
+       char c;
+       
+       if (iop->ptr == iop->endptr) {
+           ssize_t len;
+           
+           if ((len = read(iop->_file, (void *)iop->buffer, BUFFER)) == -1) {
+               return NULL;
+           }
+           if (len == 0) {
+               *p = 0;
+               if (s == p) {
+                   return NULL;
+               }
+               return s;
+           }
+           iop->ptr = iop->buffer;
+           iop->endptr = iop->buffer + len;
+       }
+       c = *iop->ptr++;
+       *p++ = c;
+       if ((p - s) == (n - 1)) {
+           *p = 0;
+           return s;
+       }
+       if (c == '\n') {
+           *p = 0;
+           return s;
+       }
+    }
+}
+#define fopen afsconf_fopen
+#define fclose afsconf_fclose
+#define fgets afsconf_fgets
+#else
+#define afsconf_FILE FILE
+#endif /* AFS_SUN5_ENV && ! __sparcv9 */
+
 /* return port number in network byte order in the low 16 bits of a long; return -1 if not found */
 static afs_int32
 afsconf_FindService(register const char *aname)
@@ -311,7 +418,7 @@ afsconf_Open(register const char *adir)
        if (!(afsconf_path = getenv("AFSCONF"))) {
            /* The "AFSCONF" environment (or contents of "/.AFSCONF") will be typically set to something like "/afs/<cell>/common/etc" where, by convention, the default files for "ThisCell" and "CellServDB" will reside; note that a major drawback is that a given afs client on that cell may NOT contain the same contents... */
            char *home_dir;
-           FILE *fp;
+           afsconf_FILE *fp;
            size_t len;
 
            if (!(home_dir = getenv("HOME"))) {
@@ -366,26 +473,31 @@ afsconf_Open(register const char *adir)
     return tdir;
 }
 
-
 static int
 GetCellUnix(struct afsconf_dir *adir)
 {
     int rc;
     char tbuffer[256];
-    FILE *tf;
-
+    int fd;
+    
     strcompose(tbuffer, 256, adir->name, "/", AFSDIR_THISCELL_FILE, NULL);
-    tf = fopen(tbuffer, "r");
-    if (tf) {
-       /* FIXME: buffer overflow waiting to happen */
-       rc = fscanf(tf, "%s", tbuffer);
-       if (rc == 1) {
-           adir->cellName = (char *)malloc(strlen(tbuffer) + 1);
-           strcpy(adir->cellName, tbuffer);
-       }
-       fclose(tf);
+    fd = open(tbuffer, O_RDONLY, 0);
+    if (fd < 0) {
+        return -1;
     } else {
-       return -1;
+       int sz;
+
+       memset(tbuffer, 0, 256);
+        sz = read(fd, tbuffer, 255);
+        close(fd);
+        if (sz > 0) {
+           char *p = strchr(tbuffer, '\n');
+           if (p)
+               *p = '\0';
+
+            adir->cellName = (char *)malloc(sz + 1);
+            strncpy(adir->cellName, tbuffer, sz);
+        }
     }
     return 0;
 }
@@ -410,7 +522,7 @@ static int
 afsconf_OpenInternal(register struct afsconf_dir *adir, char *cell,
                     char clones[])
 {
-    FILE *tf;
+    afsconf_FILE *tf;
     register char *tp, *bp;
     register struct afsconf_entry *curEntry;
     struct afsconf_aliasentry *curAlias;
@@ -736,8 +848,7 @@ afsconf_GetAfsdbInfo(char *acellName, char *aservice,
                     struct afsconf_cell *acellInfo)
 {
     afs_int32 code;
-    int tservice, i;
-    size_t len;
+    int tservice, i, len;
     unsigned char answer[1024];
     unsigned char *p;
     char *dotcellname;