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- /* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- /* buffers.c */
- #include "or.h"
- extern or_options_t options; /* command-line and config-file options */
- /* Create a new buf of size MAX_BUF_SIZE. Write a pointer to it
- * into *buf, write MAX_BUF_SIZE into *buflen, and initialize
- * *buf_datalen to 0. Return 0.
- */
- int buf_new(char **buf, int *buflen, int *buf_datalen) {
- assert(buf && buflen && buf_datalen);
- *buf = (char *)tor_malloc(MAX_BUF_SIZE);
- // memset(*buf,0,MAX_BUF_SIZE);
- *buflen = MAX_BUF_SIZE;
- *buf_datalen = 0;
- return 0;
- }
- void buf_free(char *buf) {
- free(buf);
- }
- /* read from socket s, writing onto buf+buf_datalen.
- * read at most 'at_most' bytes, and in any case don't read more than will fit based on buflen.
- * If read() returns 0, set *reached_eof to 1 and return 0. If you want to tear
- * down the connection return -1, else return the number of bytes read.
- */
- int read_to_buf(int s, int at_most, char **buf, int *buflen, int *buf_datalen, int *reached_eof) {
- int read_result;
- #ifdef MS_WINDOWS
- int e;
- #endif
- assert(buf && *buf && buflen && buf_datalen && reached_eof && (s>=0));
- /* this is the point where you would grow the buffer, if you want to */
- if(at_most > *buflen - *buf_datalen)
- at_most = *buflen - *buf_datalen; /* take the min of the two */
- if(at_most == 0)
- return 0; /* we shouldn't read anything */
- if(!options.LinkPadding && at_most > 10*sizeof(cell_t)) {
- /* if no linkpadding: do a rudimentary round-robin so one
- * connection can't hog a thickpipe
- */
- at_most = 10*(CELL_PAYLOAD_SIZE - RELAY_HEADER_SIZE);
- /* XXX this still isn't perfect. now we read 10 relay data payloads per read --
- * but if we're reading from a connection that speaks cells, we always
- * read a partial cell from the network and can't process it yet. Good
- * enough for now though. (And maybe best, to stress our code more.)
- */
- }
- // log_fn(LOG_DEBUG,"reading at most %d bytes.",at_most);
- read_result = read(s, *buf+*buf_datalen, at_most);
- if (read_result < 0) {
- if(!ERRNO_EAGAIN(errno)) { /* it's a real error */
- return -1;
- }
- #ifdef MS_WINDOWS
- e = correct_socket_errno(s);
- if(!ERRNO_EAGAIN(errno)) { /* no, it *is* a real error! */
- return -1;
- }
- #endif
- return 0;
- } else if (read_result == 0) {
- log_fn(LOG_DEBUG,"Encountered eof");
- *reached_eof = 1;
- return 0;
- } else { /* we read some bytes */
- *buf_datalen += read_result;
- // log_fn(LOG_DEBUG,"Read %d bytes. %d on inbuf.",read_result, *buf_datalen);
- return read_result;
- }
- }
- int flush_buf(int s, char **buf, int *buflen, int *buf_flushlen, int *buf_datalen) {
- /* push from buf onto s
- * then memmove to front of buf
- * return -1 or how many bytes remain to be flushed */
- int write_result;
- #ifdef MS_WINDOWS
- int e;
- #endif
- assert(buf && *buf && buflen && buf_flushlen && buf_datalen && (s>=0) && (*buf_flushlen <= *buf_datalen));
- if(*buf_flushlen == 0) /* nothing to flush */
- return 0;
- /* this is the point where you would grow the buffer, if you want to */
- write_result = write(s, *buf, *buf_flushlen);
- if (write_result < 0) {
- if(!ERRNO_EAGAIN(errno)) { /* it's a real error */
- return -1;
- }
- #ifdef MS_WINDOWS
- e = correct_socket_errno(s);
- if(!ERRNO_EAGAIN(errno)) { /* no, it *is* a real error! */
- return -1;
- }
- #endif
- log_fn(LOG_DEBUG,"write() would block, returning.");
- return 0;
- } else {
- *buf_datalen -= write_result;
- *buf_flushlen -= write_result;
- memmove(*buf, *buf+write_result, *buf_datalen);
- // log_fn(LOG_DEBUG,"flushed %d bytes, %d ready to flush, %d remain.",
- // write_result,*buf_flushlen,*buf_datalen);
- return *buf_flushlen;
- }
- }
- int write_to_buf(char *string, int string_len,
- char **buf, int *buflen, int *buf_datalen) {
- /* append string to buf (growing as needed, return -1 if "too big")
- * return total number of bytes on the buf
- */
- assert(string && buf && *buf && buflen && buf_datalen);
- /* this is the point where you would grow the buffer, if you want to */
- if (string_len + *buf_datalen > *buflen) { /* we're out of luck */
- log_fn(LOG_DEBUG, "buflen too small. Time to implement growing dynamic bufs.");
- return -1;
- }
- memcpy(*buf+*buf_datalen, string, string_len);
- *buf_datalen += string_len;
- // log_fn(LOG_DEBUG,"added %d bytes to buf (now %d total).",string_len, *buf_datalen);
- return *buf_datalen;
- }
- int fetch_from_buf(char *string, int string_len,
- char **buf, int *buflen, int *buf_datalen) {
- /* There must be string_len bytes in buf; write them onto string,
- * then memmove buf back (that is, remove them from buf).
- *
- * Return the number of bytes still on the buffer. */
- assert(string && buf && *buf && buflen && buf_datalen);
- assert(string_len <= *buf_datalen); /* make sure we don't ask for too much */
- memcpy(string,*buf,string_len);
- *buf_datalen -= string_len;
- memmove(*buf, *buf+string_len, *buf_datalen);
- return *buf_datalen;
- }
- int find_on_inbuf(char *string, int string_len,
- char *buf, int buf_datalen) {
- /* find first instance of needle 'string' on haystack 'buf'. return how
- * many bytes from the beginning of buf to the end of string.
- * If it's not there, return -1.
- */
- char *location;
- char *last_possible = buf + buf_datalen - string_len;
- assert(string && string_len > 0 && buf);
- if(buf_datalen < string_len)
- return -1;
- for(location = buf; location <= last_possible; location++)
- if((*location == *string) && !memcmp(location+1, string+1, string_len-1))
- return location-buf+string_len;
- return -1;
- }
- /*
- Local Variables:
- mode:c
- indent-tabs-mode:nil
- c-basic-offset:2
- End:
- */
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