/* * $Id: talk.c,v 1.6 1994/05/25 07:46:30 bert Exp bert $ * * communication with client and parsing the request * (part of diswww, a Discuss->WWW gateway) */ #ifndef lint static char rcsid_talk[] = "$Id: talk.c,v 1.6 1994/05/25 07:46:30 bert Exp bert $"; #endif #include "proto.h" /* the copyright notice is included in this file, too. */ #include "extern.h" #include "version.h" #include #include #include #include #include #include #include #include #include #include #include "status.h" /*** TODO: auto-confiscate this ***/ #if defined(__sun__) && !defined(__svr4__) && !defined(__NetBSD__) #define SUNOS4 #endif #if defined(SUNOS4) #define memmove(a, b, c) bcopy(b, a, c) #endif /*** end of TODO ***/ /* status codes */ char S_ok[] = "200 Document follows"; char S_moved[] = "301 The meeting has been moved"; char S_bad_request[] = "400 Bad request"; char S_forbidden[] = "403 Forbidden"; char S_not_found[] = "404 Not Found"; char S_internal_error[] = "500 Internal error"; char S_not_implemented[] = "501 Not implemented"; /* encoding types */ char T_plain[] = "text/plain"; char T_html[] = "text/html"; /* error reply formats */ char E_not_found_fmt[] = "Document '%s' does not exist on this gateway."; char E_bad_method_fmt[] = "Method '%s' isn't supported."; char E_missing_method[] = "No method found in request."; char E_mtg_error_fmt[] = "%s. (%s:%s)"; char E_trn_error_fmt[] = "%s. ([%d] in %s:%s)"; char error_title[] = "Error: %s\r\n\

Error: %s

\r\n"; char error_fmt[] = "

\r\n\ If you believe this is an error in the server and wish to report it,\r\n\ please send a mail message including the URL, information about your\r\n\ browser and any other relevant details to

\r\n\

\r\n"; char moved_message[] = "Document Moved\r\n\

Document Moved

\r\n\ The document you are looking for was moved to '%s'.

\r\n\ If you ever see this error message, then your client is way old.\r\n\ You should consider upgrading to a client that understands document\r\n\ forwarding.

\r\n\

\r\n"; /* random other static strings */ char header_fmt[] = "HTTP/1.0 %s\r\n\ Server: %s\r\n\ MIME-version: 1.0\r\n\ Content-type: %s\r\n"; char crlf[] = "\r\n"; char w_buf[SRV_REPLYSIZE]; /* temporary buffer for random output */ /* * read in a line of text. * The line is supposed to be terminated by CRLF or LF. * rl -- structure containing the socket fd and buffering information * line -- pointer to the line of text (passed by reference) * returns: 0 on success, <0 on error * Upon return, *line contains a line inside a fixed buffer (or NULL * if stream is empty). Note that this means any strings we want to * keep must be copied away before the next read. */ int read_line(struct clt_sock *rl, char **line) { int i, idx, size; /* * The part that has been read but not processed lies between * rl->begin and rl->size-1, inclusively. * (If rl->begin == rl->size, all data has been processed.) */ /* check if we already have a LF */ for (i = rl->begin; ((i < rl->size) && (rl->buf[i] != LF_CHAR)); i++); /* if we don't, move data to the beginning of the buffer */ if ((i >= rl->size) && (rl->begin <= rl->size) && (rl->begin > 0)) { rl->size -= rl->begin; /* after this, i stays >= rl->size */ memmove(&rl->buf[0], &rl->buf[rl->begin], (size_t)rl->size); rl->begin = 0; } if (i >= rl->size) { /* get a complete line */ if (rl->size >= SRV_BUFSIZE) { /* out of buffer space? */ SYSLOG_WARNING("line too long, ask a wizard to shrink the client. =)"); *line = NULL; return -1; /* drop the connection */ } /* assume select() already said reading was OK */ idx = rl->size; /* read data and adjust rl->size */ if ((size = read(rl->fd, &rl->buf[rl->size], SRV_BUFSIZE-rl->size)) <= 0) { *line = NULL; if (errno == EWOULDBLOCK) return 0; else { SYSLOG_EWARN("read from socket failed"); return -2; /* drop the connection */ } } rl->size += size; /* check only the newly read portion for LF's */ for (i = idx; ((i < rl->size) && (rl->buf[i] != LF_CHAR)); i++); } if (i >= rl->size) { *line = NULL; return 0; } /* strip [CR]LF and make the line into a \0-terminated string */ rl->buf[i] = 0; if ((i > 0) && (rl->buf[i-1] == CR_CHAR)) { rl->buf[i-1] = 0; #ifdef DEBUG } else { SYSLOG_NOTICE("broken client does not use CR."); #endif } idx = rl->begin; /* keep the value of rl->begin for return... */ rl->begin = i+1; /* ...and point rl->begin to next line */ *line = (&rl->buf[idx]); return 0; } /* * notify the client on error. * clt -- structure containing the socket fd * status -- status code and description (e.g., "404 Not Found") * fmt -- printf-style format to make the description of error * ... -- printf-style arguments * See also: send_moved_notice */ void send_error_notice(struct clt_sock *clt, char *status, char *fmt, ...) { va_list pvar; if (clt->ver) send_header(clt, status, T_html); fd_print(clt->fd, error_title, status, status); va_start(pvar, fmt); vsprintf(w_buf, fmt, pvar); va_end(pvar); fd_write(clt->fd, w_buf); fd_print(clt->fd, error_fmt, SRV_WEBMASTER); #ifdef DEBUG SYSLOG(LOG_DEBUG, "%s just got a %s", clt->host, status); #endif } /* * notify the client that a meeting was moved. * clt -- structure containing the socket fd * status -- status code and description (e.g., "303 The meeting moved") * url -- URL to point the client at * See also: send_error_notice */ void send_moved_notice(struct clt_sock *clt, char *status, char *url) { if (clt->ver) send_header2(clt, status, T_html, "URI: ", url, "The meeting has moved. \r\n" "Location: ", url, "\r\n", (char*)0); fd_print(clt->fd, moved_message, url, SRV_WEBMASTER); #ifdef DEBUG SYSLOG(LOG_DEBUG, "%s just got pointed at %s", clt->host, url); #endif } /* * send the default HTTP/1.0 reply headers to the client. * clt -- structure containing the socket fd * status -- status code and description (e.g., "200 OK") * type -- content type (must be "text/html" for errors) */ void send_header(struct clt_sock *clt, char *status, char *type) { fd_print(clt->fd, header_fmt, status, DISWWW_VERSION, type); fd_write(clt->fd, crlf); } /* * send default and specified HTTP/1.0 reply headers to the client. * clt -- structure containing the socket fd * status -- status code and description (e.g., "200 OK") * type -- content type (must be "text/html" for errors) * ... -- strings containing the additional headers */ void send_header2(struct clt_sock *clt, char *status, char *type, ...) { va_list pvar; char *arg; fd_print(clt->fd, header_fmt, status, DISWWW_VERSION, type); va_start(pvar, type); while (arg = va_arg(pvar, char*)) fd_write(clt->fd, arg); va_end(pvar); fd_write(clt->fd, crlf); } /* * read the request and headers from the client. * clt -- structure containing the socket fd * returns: 0 on success, <0 on errors */ int talk_to_client(struct clt_sock *clt) { char* line; if (! clt->method) { /* is this the first line? */ /* read request */ if (read_line(clt, &line) < 0) return -1; /* error? */ if (line == NULL) return -1; /* no data? */ /* tokenize request into method, path and protocol version */ if (! (clt->method = strtok(line, " "))) { /* assume not HTTP/1.0 */ send_error_notice(clt, S_bad_request, E_missing_method); return -1; } if (! (clt->path = strtok(NULL, " "))) { clt->path = "/"; clt->ver = NULL; } else { clt->ver = strtok(NULL," "); } /* replicate strings so buffer can change */ clt->method = sstrdup(clt->method); clt->path = sstrdup(clt->path); clt->ver = sstrdup(clt->ver); } if (clt->ver) { /* if not HTTP/1.0, we're done */ do { /* otherwise, read headers */ if (read_line(clt, &line) < 0) return -1; /* error? */ if (line == NULL) return 0; /* no data? */ if (! strncasecmp("User-Agent: ",line,12)) clt->agent = sstrdup(line+12); /* processing of headers goes here */ } while ((*line) != (char)0); } /* if we're here, we have a complete request */ if (strcasecmp(clt->method,"GET")) { send_error_notice(clt, S_not_implemented, E_bad_method_fmt, clt->method); return -1; } return 0; }