diff options
Diffstat (limited to 'nss')
| -rw-r--r-- | nss/nss_files/files-XXX.c | 59 |
1 files changed, 51 insertions, 8 deletions
diff --git a/nss/nss_files/files-XXX.c b/nss/nss_files/files-XXX.c index 082d1ea2b7..b62208c324 100644 --- a/nss/nss_files/files-XXX.c +++ b/nss/nss_files/files-XXX.c @@ -179,8 +179,51 @@ CONCAT(_nss_files_end,ENTNAME) (void) return NSS_STATUS_SUCCESS; } -/* Parsing the database file into `struct STRUCTURE' data structures. */ +typedef enum +{ + gcr_ok = 0, + gcr_error = -1, + gcr_overflow = -2 +} get_contents_ret; + +/* Hack around the fact that fgets only accepts int sizes. */ +static get_contents_ret +get_contents (char *linebuf, size_t len, FILE *stream) +{ + size_t remaining_len = len; + char *curbuf = linebuf; + + do + { + int curlen = ((remaining_len > (size_t) INT_MAX) ? INT_MAX + : remaining_len); + char *p = fgets_unlocked (curbuf, curlen, stream); + + ((unsigned char *) curbuf)[curlen - 1] = 0xff; + + /* EOF or read error. */ + if (p == NULL) + return gcr_error; + + /* Done reading in the line. */ + if (((unsigned char *) curbuf)[curlen - 1] == 0xff) + return gcr_ok; + + /* Drop the terminating '\0'. */ + remaining_len -= curlen - 1; + curbuf += curlen - 1; + } + /* fgets copies one less than the input length. Our last iteration is of + REMAINING_LEN and once that is done, REMAINING_LEN is decremented by + REMAINING_LEN - 1, leaving the result as 1. */ + while (remaining_len > 1); + + /* This means that the current buffer was not large enough. */ + return gcr_overflow; +} + +/* Parsing the database file into `struct STRUCTURE' data structures. */ static enum nss_status internal_getent (struct STRUCTURE *result, char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO @@ -188,7 +231,7 @@ internal_getent (struct STRUCTURE *result, { char *p; struct parser_data *data = (void *) buffer; - int linebuflen = buffer + buflen - data->linebuffer; + size_t linebuflen = buffer + buflen - data->linebuffer; int parse_result; if (buflen < sizeof *data + 2) @@ -200,17 +243,16 @@ internal_getent (struct STRUCTURE *result, do { - /* Terminate the line so that we can test for overflow. */ - ((unsigned char *) data->linebuffer)[linebuflen - 1] = '\xff'; + get_contents_ret r = get_contents (data->linebuffer, linebuflen, stream); - p = fgets_unlocked (data->linebuffer, linebuflen, stream); - if (p == NULL) + if (r == gcr_error) { /* End of file or read error. */ H_ERRNO_SET (HOST_NOT_FOUND); return NSS_STATUS_NOTFOUND; } - else if (((unsigned char *) data->linebuffer)[linebuflen - 1] != 0xff) + + if (r == gcr_overflow) { /* The line is too long. Give the user the opportunity to enlarge the buffer. */ @@ -219,7 +261,8 @@ internal_getent (struct STRUCTURE *result, return NSS_STATUS_TRYAGAIN; } - /* Skip leading blanks. */ + /* Everything OK. Now skip leading blanks. */ + p = data->linebuffer; while (isspace (*p)) ++p; } |