/* $Id: talk.c,v 1.5 94/03/11 23:10:32 bert Exp $ */ #include "extern.h" #include "proto.h" #include "version.h" #include #include #include #include #include #include #include #include #include #include #include "status.h" /* status codes */ char S_ok[] = "200 Document follows"; char S_bad_request[] = "400 Bad request"; char S_unauthorized[] = "401 Unauthorized"; 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 error_title[] = "Server Error: %s\r\n\

Server Error: %s

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

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

\r\n\

\r\n"; /* random other static strings */ char header_fmt[] = "HTTP/1.0 %s\r\n\ Server: diswww/%s\r\n\ MIME-version: 1.0\r\n\ Content-type: %s\r\n\r\n"; char w_buf[SRV_REPLYSIZE]; /* temporary buffer for random output */ /* * fd_write is just a simple wrapper for write() */ int fd_write(int fd, char* text) { return write(fd, text, strlen(text)); } /* * fd_print is similar to fprintf, but without buffering. * The caller needs to make sure that the length of the output string * won't be more than SRV_REPLYSIZE bytes long. */ int fd_print(int fd, const char* fmt, ...) { va_list pvar; va_start(pvar, fmt); vsprintf(w_buf, fmt, pvar); va_end(pvar); return fd_write(fd, w_buf); } /* * This copies the contents of the named file to the file descriptor. */ void fd_spew_file(int fd, char* fname) { int in, rr, ww, wp; if ((in = open(fname, 0, O_RDONLY)) < 0) { SYSLOG_ERROR("open() failed"); exit(10); } while ((rr = read(in, w_buf, SRV_REPLYSIZE)) > 0) { wp = 0; while (wp < rr) { if ((ww = write(fd, &w_buf[wp], rr-wp)) < 0) { SYSLOG_ERROR("write() failed"); exit(10); } wp += ww; } } if (rr < 0) { SYSLOG_ERROR("read() failed"); exit(10); } close(in); } /* * read_line reads a line of text from the socket in structure rl. * The line is supposed to be terminated by CRLF or LF. The function * returns status (<0 on error). A pointer to the line inside a * buffer (or NULL if stream is empty) is returned in variable line. * 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; } else { SYSLOG_NOTICE("broken client does not use CR."); } 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; } /* * This function is used to notify the client on error. The first * argument is the fd, the second is the status code string. The rest * are the printf-style format and arguments to make the description * of error condition. */ 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 } /* * This function is used to send the HTTP/1.0 reply header to the * client. The first argument is the status code string, and the * second is the MIME content-type identifier. */ void send_header(struct clt_sock *clt, char *status, char *type) { fd_print(clt->fd, header_fmt, status, DISWWW_VERSION, type); } /* * perform a conversation with client (read request and output reply) */ int talk_to_client(struct clt_sock *clt) { char* line; if (clt->reply) return 0; /* already done? */ 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 = strdup(clt->method); clt->path = strdup(clt->path); clt->ver = strdup(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 = strdup(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; }