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- /* Copyright 2001,2002,2003 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 */
- struct buf_t {
- char *buf;
- size_t len;
- size_t datalen;
- };
- #define BUF_OK(b) ((b) && (b)->buf && (b)->datalen <= (b)->len)
- /* Find the first instance of str on buf. If none exists, return -1.
- * Otherwise, return index of the first character in buf _after_ the
- * first instance of str.
- */
- static int find_str_in_str(const char *str, int str_len,
- const char *buf, int buf_len)
- {
- const char *location;
- const char *last_possible = buf + buf_len - str_len;
- assert(str && str_len > 0 && buf);
- if(buf_len < str_len)
- return -1;
- for(location = buf; location <= last_possible; location++)
- if((*location == *str) && !memcmp(location+1, str+1, str_len-1))
- return location-buf+str_len;
- return -1;
- }
- int find_on_inbuf(char *string, int string_len, buf_t *buf) {
- return find_str_in_str(string, string_len, buf->buf, buf->datalen);
- }
- /* Create and return a new buf of size 'size'
- */
- buf_t *buf_new_with_capacity(size_t size) {
- buf_t *buf;
- buf = (buf_t*)tor_malloc(sizeof(buf_t));
- buf->buf = (char *)tor_malloc(size);
- buf->len = size;
- buf->datalen = 0;
- // memset(buf->buf,0,size);
- assert(BUF_OK(buf));
- return buf;
- }
- buf_t *buf_new()
- {
- return buf_new_with_capacity(MAX_BUF_SIZE);
- }
- size_t buf_datalen(const buf_t *buf)
- {
- return buf->datalen;
- }
- size_t buf_capacity(const buf_t *buf)
- {
- return buf->len;
- }
- const char *_buf_peek_raw_buffer(const buf_t *buf)
- {
- return buf->buf;
- }
- void buf_free(buf_t *buf) {
- assert(buf && buf->buf);
- free(buf->buf);
- free(buf);
- }
- /* read from socket s, writing onto end of buf.
- * 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, buf_t *buf, int *reached_eof) {
- int read_result;
- #ifdef MS_WINDOWS
- int e;
- #endif
- assert(BUF_OK(buf) && reached_eof && (s>=0));
- /* this is the point where you would grow the buffer, if you want to */
- if(at_most > buf->len - buf->datalen)
- at_most = buf->len - buf->datalen; /* take the min of the two */
- if(at_most == 0)
- return 0; /* we shouldn't read anything */
- // log_fn(LOG_DEBUG,"reading at most %d bytes.",at_most);
- read_result = read(s, buf->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(e)) { /* 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,
- (int)buf->datalen);
- return read_result;
- }
- }
- int read_to_buf_tls(tor_tls *tls, int at_most, buf_t *buf) {
- int r;
- assert(tls && BUF_OK(buf));
-
- if (at_most > buf->len - buf->datalen)
- at_most = buf->len - buf->datalen;
- if (at_most == 0)
- return 0;
-
- r = tor_tls_read(tls, buf->buf+buf->datalen, at_most);
- if (r<0)
- return r;
- buf->datalen += r;
- log_fn(LOG_DEBUG,"Read %d bytes. %d on inbuf.",r, (int)buf->datalen);
- return r;
- }
- int flush_buf(int s, buf_t *buf, int *buf_flushlen)
- {
- /* 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_OK(buf) && buf_flushlen && (s>=0) && (*buf_flushlen <= buf->datalen));
- if(*buf_flushlen == 0) /* nothing to flush */
- return 0;
- write_result = write(s, buf->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(e)) { /* 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, buf->buf+write_result, buf->datalen);
- log_fn(LOG_DEBUG,"%d: flushed %d bytes, %d ready to flush, %d remain.",
- s,write_result,*buf_flushlen,(int)buf->datalen);
- return *buf_flushlen;
- /* XXX USE_TLS should change to return write_result like any sane function would */
- }
- }
- int flush_buf_tls(tor_tls *tls, buf_t *buf, int *buf_flushlen)
- {
- int r;
- assert(tls && BUF_OK(buf) && buf_flushlen);
- /* we want to let tls write even if flushlen is zero, because it might
- * have a partial record pending */
- r = tor_tls_write(tls, buf->buf, *buf_flushlen);
- if (r < 0) {
- return r;
- }
- buf->datalen -= r;
- *buf_flushlen -= r;
- memmove(buf->buf, buf->buf+r, buf->datalen);
- log_fn(LOG_DEBUG,"flushed %d bytes, %d ready to flush, %d remain.",
- r,*buf_flushlen,(int)buf->datalen);
- return r;
- }
- int write_to_buf(const char *string, int string_len, buf_t *buf) {
- /* append string to buf (growing as needed, return -1 if "too big")
- * return total number of bytes on the buf
- */
- assert(string && BUF_OK(buf));
- /* this is the point where you would grow the buffer, if you want to */
- if (string_len + buf->datalen > buf->len) { /* we're out of luck */
- log_fn(LOG_WARN, "buflen too small. Time to implement growing dynamic bufs.");
- return -1;
- }
- memcpy(buf->buf+buf->datalen, string, string_len);
- buf->datalen += string_len;
- log_fn(LOG_DEBUG,"added %d bytes to buf (now %d total).",string_len, (int)buf->datalen);
- return buf->datalen;
- }
- int fetch_from_buf(char *string, int string_len, buf_t *buf) {
- /* 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_OK(buf));
- assert(string_len <= buf->datalen); /* make sure we don't ask for too much */
- memcpy(string,buf->buf,string_len);
- buf->datalen -= string_len;
- memmove(buf->buf, buf->buf+string_len, buf->datalen);
- return buf->datalen;
- }
- /* There is a (possibly incomplete) http statement on *buf, of the
- * form "%s\r\n\r\n%s", headers, body.
- * If a) the headers include a Content-Length field and all bytes in
- * the body are present, or b) there's no Content-Length field and
- * all headers are present, then:
- * copy headers and body into the supplied args (and null terminate
- * them), remove them from buf, and return 1.
- * (If headers or body is NULL, discard that part of the buf.)
- * If a headers or body doesn't fit in the arg, return -1.
- *
- * Else, change nothing and return 0.
- */
- int fetch_from_buf_http(buf_t *buf,
- char *headers_out, int max_headerlen,
- char *body_out, int max_bodylen) {
- char *headers, *body;
- int i;
- int headerlen, bodylen, contentlen;
- assert(BUF_OK(buf));
- headers = buf->buf;
- i = find_on_inbuf("\r\n\r\n", 4, buf);
- if(i < 0) {
- log_fn(LOG_DEBUG,"headers not all here yet.");
- return 0;
- }
- body = buf->buf+i;
- headerlen = body-headers; /* includes the CRLFCRLF */
- bodylen = buf->datalen - headerlen;
- log_fn(LOG_DEBUG,"headerlen %d, bodylen %d.",headerlen,bodylen);
- if(headers_out && max_headerlen <= headerlen) {
- log_fn(LOG_WARN,"headerlen %d larger than %d. Failing.", headerlen, max_headerlen-1);
- return -1;
- }
- if(body_out && max_bodylen <= bodylen) {
- log_fn(LOG_WARN,"bodylen %d larger than %d. Failing.", bodylen, max_bodylen-1);
- return -1;
- }
- #define CONTENT_LENGTH "\r\nContent-Length: "
- i = find_str_in_str(CONTENT_LENGTH, strlen(CONTENT_LENGTH),
- headers, headerlen);
- if(i > 0) {
- contentlen = atoi(headers+i);
- /* XXX What if content-length is malformed? */
- log_fn(LOG_DEBUG,"Got a contentlen of %d.",contentlen);
- if(bodylen < contentlen) {
- log_fn(LOG_DEBUG,"body not all here yet.");
- return 0; /* not all there yet */
- }
- bodylen = contentlen;
- log_fn(LOG_DEBUG,"bodylen reduced to %d.",bodylen);
- }
- /* all happy. copy into the appropriate places, and return 1 */
- if(headers_out) {
- memcpy(headers_out,buf->buf,headerlen);
- headers_out[headerlen] = 0; /* null terminate it */
- }
- if(body_out) {
- memcpy(body_out,buf->buf+headerlen,bodylen);
- body_out[bodylen] = 0; /* null terminate it */
- }
- buf->datalen -= (headerlen+bodylen);
- memmove(buf->buf, buf->buf+headerlen+bodylen, buf->datalen);
- return 1;
- }
- /* There is a (possibly incomplete) socks handshake on buf, of one
- * of the forms
- * socks4: "socksheader username\0"
- * socks4a: "socksheader username\0 destaddr\0"
- * socks5 phase one: "version #methods methods"
- * socks5 phase two: "version command 0 addresstype..."
- * If it's a complete and valid handshake, and destaddr fits in addr_out,
- * then pull the handshake off the buf, assign to addr_out and port_out,
- * and return 1.
- * If it's invalid or too big, return -1.
- * Else it's not all there yet, leave buf alone and return 0.
- * If you want to specify the socks reply, write it into *reply
- * and set *replylen, else leave *replylen alone.
- * If returning 0 or -1, *addr_out and *port_out are undefined.
- */
- int fetch_from_buf_socks(buf_t *buf, char *socks_version,
- char *reply, int *replylen,
- char *addr_out, int max_addrlen,
- uint16_t *port_out) {
- unsigned char len;
- char *tmpbuf=NULL;
- uint32_t destip;
- enum {socks4, socks4a} socks4_prot = socks4a;
- char *next, *startaddr;
- struct in_addr in;
- if(buf->datalen < 2) /* version and another byte */
- return 0;
- switch(*(buf->buf)) { /* which version of socks? */
- case 5: /* socks5 */
- if(*socks_version != 5) { /* we need to negotiate a method */
- unsigned char nummethods = (unsigned char)*(buf->buf+1);
- assert(!*socks_version);
- log_fn(LOG_DEBUG,"socks5: learning offered methods");
- if(buf->datalen < 2+nummethods)
- return 0;
- if(!nummethods || !memchr(buf->buf+2, 0, nummethods)) {
- log_fn(LOG_WARN,"socks5: offered methods don't include 'no auth'. Rejecting.");
- *replylen = 2; /* 2 bytes of response */
- *reply = 5; /* socks5 reply */
- *(reply+1) = 0xFF; /* reject all methods */
- return -1;
- }
- buf->datalen -= (2+nummethods); /* remove packet from buf */
- memmove(buf->buf, buf->buf + 2 + nummethods, buf->datalen);
- *replylen = 2; /* 2 bytes of response */
- *reply = 5; /* socks5 reply */
- *(reply+1) = 0; /* choose the 'no auth' method */
- *socks_version = 5; /* remember that we've already negotiated auth */
- log_fn(LOG_DEBUG,"socks5: accepted method 0");
- return 0;
- }
- /* we know the method; read in the request */
- log_fn(LOG_DEBUG,"socks5: checking request");
- if(buf->datalen < 8) /* basic info plus >=2 for addr plus 2 for port */
- return 0; /* not yet */
- if(*(buf->buf+1) != 1) { /* not a connect? we don't support it. */
- log_fn(LOG_WARN,"socks5: command %d not '1'.",*(buf->buf+1));
- return -1;
- }
- switch(*(buf->buf+3)) { /* address type */
- case 1: /* IPv4 address */
- log_fn(LOG_DEBUG,"socks5: ipv4 address type");
- if(buf->datalen < 10) /* ip/port there? */
- return 0; /* not yet */
- destip = ntohl(*(uint32_t*)(buf->buf+4));
- in.s_addr = htonl(destip);
- tmpbuf = inet_ntoa(in);
- if(strlen(tmpbuf)+1 > max_addrlen) {
- log_fn(LOG_WARN,"socks5 IP takes %d bytes, which doesn't fit in %d",
- strlen(tmpbuf)+1,max_addrlen);
- return -1;
- }
- strcpy(addr_out,tmpbuf);
- *port_out = ntohs(*(uint16_t*)(buf->buf+8));
- buf->datalen -= 10;
- memmove(buf->buf, buf->buf+10, buf->datalen);
- return 1;
- case 3: /* fqdn */
- log_fn(LOG_DEBUG,"socks5: fqdn address type");
- len = (unsigned char)*(buf->buf+4);
- if(buf->datalen < 7+len) /* addr/port there? */
- return 0; /* not yet */
- if(len+1 > max_addrlen) {
- log_fn(LOG_WARN,"socks5 hostname is %d bytes, which doesn't fit in %d",
- len+1,max_addrlen);
- return -1;
- }
- memcpy(addr_out,buf->buf+5,len);
- addr_out[len] = 0;
- *port_out = ntohs(*(uint16_t*)(buf->buf+5+len));
- buf->datalen -= (5+len+2);
- memmove(buf->buf, buf->buf+(5+len+2), buf->datalen);
- return 1;
- default: /* unsupported */
- log_fn(LOG_WARN,"socks5: unsupported address type %d",*(buf->buf+3));
- return -1;
- }
- assert(0);
- case 4: /* socks4 */
- *socks_version = 4;
- if(buf->datalen < SOCKS4_NETWORK_LEN) /* basic info available? */
- return 0; /* not yet */
- if(*(buf->buf+1) != 1) { /* not a connect? we don't support it. */
- log_fn(LOG_WARN,"socks4: command %d not '1'.",*(buf->buf+1));
- return -1;
- }
- *port_out = ntohs(*(uint16_t*)(buf->buf+2));
- destip = ntohl(*(uint32_t*)(buf->buf+4));
- if(!*port_out || !destip) {
- log_fn(LOG_WARN,"socks4: Port or DestIP is zero.");
- return -1;
- }
- if(destip >> 8) {
- log_fn(LOG_DEBUG,"socks4: destip not in form 0.0.0.x.");
- in.s_addr = htonl(destip);
- tmpbuf = inet_ntoa(in);
- if(strlen(tmpbuf)+1 > max_addrlen) {
- log_fn(LOG_WARN,"socks4 addr (%d bytes) too long.", strlen(tmpbuf));
- return -1;
- }
- log_fn(LOG_DEBUG,"socks4: successfully read destip (%s)", tmpbuf);
- socks4_prot = socks4;
- }
- next = memchr(buf->buf+SOCKS4_NETWORK_LEN, 0, buf->datalen);
- if(!next) {
- log_fn(LOG_DEBUG,"Username not here yet.");
- return 0;
- }
- startaddr = next+1;
- if(socks4_prot == socks4a) {
- next = memchr(startaddr, 0, buf->buf+buf->datalen-startaddr);
- if(!next) {
- log_fn(LOG_DEBUG,"Destaddr not here yet.");
- return 0;
- }
- if(max_addrlen <= next-startaddr) {
- log_fn(LOG_WARN,"Destaddr too long.");
- return -1;
- }
- }
- log_fn(LOG_DEBUG,"Everything is here. Success.");
- strcpy(addr_out, socks4_prot == socks4 ? tmpbuf : startaddr);
- buf->datalen -= (next-buf->buf+1); /* next points to the final \0 on inbuf */
- memmove(buf->buf, next+1, buf->datalen);
- return 1;
- default: /* version is not socks4 or socks5 */
- log_fn(LOG_WARN,"Socks version %d not recognized. (Tor is not an httpd proxy.)",*(buf->buf));
- return -1;
- }
- }
- /*
- Local Variables:
- mode:c
- indent-tabs-mode:nil
- c-basic-offset:2
- End:
- */
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