diff options
Diffstat (limited to 'gopher.filter.dpi.c')
| -rw-r--r-- | gopher.filter.dpi.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/gopher.filter.dpi.c b/gopher.filter.dpi.c new file mode 100644 index 0000000..5e40b2a --- /dev/null +++ b/gopher.filter.dpi.c @@ -0,0 +1,469 @@ +#include <err.h> +#include <errno.h> +#include <stdarg.h> +#include <stdio.h> +#include <string.h> +#include <fcntl.h> +#include <sys/types.h> + +#include "dpi.h" +#include "io.h" + +static void respond_errstr(const char *errstr, const char *fmt, ...) { + va_list ap; + int err = errno; + va_start(ap, fmt); + dpi_send_header(NULL, "text/plain"); + vprintf(fmt, ap); + printf(": %s", errstr ? errstr : strerror(err)); + va_end(ap); +} + +static void respond_err(const char *fmt, ...) { + va_list ap; + int err = errno; + va_start(ap, fmt); + dpi_send_header(NULL, "text/plain"); + vprintf(fmt, ap); + printf(": %s", strerror(err)); + va_end(ap); +} + +static void respond_errx(const char *fmt, ...) { + va_list ap; + int err = errno; + va_start(ap, fmt); + dpi_send_header(NULL, "text/plain"); + vprintf(fmt, ap); + va_end(ap); +} + +static int parse_type_path(const char *url, char *type, char *path, size_t path_len) { + if (!*url) { + *path = '\0'; + *type = '\0'; + return 0; + } + *type = *url++; + while (path_len > 0 && *url != '\0') { + *path++ = *url++; + path_len--; + } + if (path_len <= 0) { + errno = EMSGSIZE; + return -1; + } + *path = '\0'; + return 0; +} + +static int parse_port_type_path(const char *url, char *port, size_t port_len, char *type, char *path, size_t path_len) { + while (port_len > 0 && *url != '\0' && *url != '/') { + *port++ = *url++; + port_len--; + } + if (port_len <= 0) { + errno = EMSGSIZE; + return -1; + } + *port = '\0'; + if (*url == '/') return parse_type_path(url + 1, type, path, path_len); + *path = '\0'; + *type = '\0'; + return 0; +} + +static int parse_url(const char *url, char *host, size_t host_len, char *port, size_t port_len, char *type, char *path, size_t path_len) { + if (!strncmp(url, "gopher:", 7)) url += 7; + if (!strncmp(url, "//", 2)) url += 2; + + while (host_len > 0 && *url != '\0' && *url != '/' && *url != ':') { + *host++ = *url++; + host_len--; + } + if (host_len <= 0) { + errno = EMSGSIZE; + return -1; + } + *host = '\0'; + if (*url == ':') return parse_port_type_path(url + 1, port, port_len, type, path, path_len); + *port = '\0'; + if (*url == '/') return parse_type_path(url + 1, type, path, path_len); + *path = '\0'; + return 0; +} + +static void parse_line(char *line, char *type, char **title, char **selector, char **host, char **port) { + *type = *line; + if (!*line) { + *title = *selector = *host = *port = NULL; + return; + } + + *title = ++line; + while (*line && *line != '\t') line++; + if (!*line) { + *selector = *host = *port = NULL; + return; + } + *line++ = '\0'; + + *selector = line; + while (*line && *line != '\t') line++; + if (!*line) { + *host = *port = NULL; + return; + } + *line++ = '\0'; + + *host = line; + while (*line && *line != '\t') line++; + if (!*line) { + *port = NULL; + return; + } + *line++ = '\0'; + + *port = line; + while (*line && *line >= '0' && *line <= '9') line++; + *line = '\0'; +} + +static int putchar_htmlenc(char c) { + switch (c) { + case '<': return printf("<"); + case '>': return printf(">"); + case '"': return printf("""); + default: return putchar(c); + } +} + +static void print_htmlenc(const char *str) { + char c; + while ((c = *str++)) putchar_htmlenc(c); +} + +static void render_line_info(const char *title) { + printf("<tr><td></td><td><pre>"); + print_htmlenc(title); + printf("</pre></td></tr>\n"); +} + +static void render_line_unknown(char type, const char *line) { + printf("<tr><td>"); + putchar_htmlenc(type); + printf("</td><td><pre>"); + print_htmlenc(line + 1); + printf("</pre></td></tr>\n"); +} + +static void render_line_empty() { + printf("<tr><td colspan=2></td></tr>\n"); +} + +static void render_line_line() { + printf("<tr><td colspan=2><hr></td></tr>\n"); +} + +static const char *icon(char type) { + switch (type) { + case '0': // text + return "<img src=\"data:image/gif;base64,R0lGODdhFAAXAPAAMf///wAAACwAAAAAFAAXAAACOYSPqcvtD02YtFYV4Ez55S5J1gZ0INicoWixVBmNpry80WG7JLfftozC9WK9UW2oIQGPwSTw+YI+CwA7\">"; + case '1': // menu + return "<img src=\"data:image/gif;base64,R0lGODdhFAAXAPAAMf///wAAACwAAAAAFAAXAAACOYSPqcvtD1OYNAZ1XcZtL1oZHpSNJGBqoYVO0QG+aJt263mTuUbL9AWcBYctoZEIdP1AzBisCc0UAAA7\">"; + case '7': // search + return "<img src=\"data:image/gif;base64,R0lGODdhFAAXAPAAMf///wAAACwAAAAAFAAXAAACQoSPqcvtD02YtNoKQkRUWT8l2hFypSSNZ7ZqoWqOJJzFjCqzOZmKK8oC7Wq/1FC36AiTRdxShPQdldLN7ILF6rLZAgA7\">"; + case '5': + case '9': // binary + return "<img src=\"data:image/gif;base64,R0lGODdhFAAXAPAAMf///wAAACwAAAAAFAAXAAACRoSPqcvtD02YtFYV4Ez55S4dlNSVIglsW3qy6QeTVxmvr4WqIDLKKGaL3H49IO2FNOZiSqRu0XsGRavqlLqLWLbcWfcbKAAAOw==\">"; + case '8': // telnet + return "<img src=\"data:image/gif;base64,R0lGODlhFAAXAPAAAP///wAAACH5BAAAAAAALAAAAAAUABcAAAJBhI+py+0PT5i0WmpClLrjr3GAN41lKYboGmad63rICZtyWrPza8a2ymORgKMN7IK8xJJI46L1aDGZv6nS2sxsQgUAOw==\">"; + case 'g': + case 'I': // image + return "<img src=\"data:image/gif;base64,R0lGODdhFAAXAPAAMf///wAAACwAAAAAFAAXAAACQISPqcvtD02YtFYV4EzZZtSBgMdJR2eV5jimJolebXzBsrRhJP6BXk6J+HqnW5E4M844uyPT5XzmhsLj71rDYgsAOw==\">"; + case 's': // audio + return "<img src=\"data:image/gif;base64,R0lGODlhFAAXAPAAAP///wAAACH5BAAAAAAALAAAAAAUABcAAAJIhI+py+0PTZi02gpCRDRqOS1fJoHjEaJlx5GuBoeYS8KZnNj6bbd73FP9eLzPEFgM/lKolLHGbLagJ1XpFW2MWJvk5YsBiycFADs=\">"; + case 'h': // web + return "<img src=\"data:image/gif;base64,R0lGODdhFAAXAPAAMf///wAAACwAAAAAFAAXAAACQISPqcvtD02YtFYV4Ey5g8x9iOeFovRd5gmWnHWO22HNo0Nh4JKvvE0DynY/Yo/RChJ1RqFpdywOI8OatZa6agsAOw==\">"; + default: + return ""; + } +} + +static void render_line_link(char type, const char *title, const char *selector, const char *host, const char *port) { + size_t indent = 0; + while (*title == ' ') { + title++; + indent++; + } + printf("<tr><td>%s</td><td><pre>%*s<a href=\"gopher://", icon(type), indent, ""); + if (host) { + print_htmlenc(host); + } + if (port && strcmp(port, "70")) { + putchar(':'); + print_htmlenc(port); + } + if (type) { + putchar('/'); + putchar_htmlenc(type); + putchar('/'); + } + if (selector) { + if (*selector == '/') selector++; + print_htmlenc(selector); + } + printf("\">"); + if (title) { + print_htmlenc(title); + } + printf("</a></pre></td></tr>\n"); +} + +static void render_line_search(char type, const char *title, const char *selector, const char *host, const char *port) { + size_t indent = 0; + while (*title == ' ') { + title++; + indent++; + } + printf("<tr><td>%s</td><td><form method=\"get\" action=\"gopher://", icon(type)); + if (host) { + print_htmlenc(host); + } + if (port && strcmp(port, "70")) { + putchar(':'); + print_htmlenc(port); + } + if (type) { + putchar('/'); + putchar_htmlenc(type); + putchar('/'); + } + if (selector) { + if (*selector == '/') selector++; + print_htmlenc(selector); + } + printf("\"><pre>%*s", indent, ""); + printf("\n%*s<input name=__gopher__query__ size=72 placeholder=\"", indent, ""); + if (title) { + print_htmlenc(title); + } + printf("\"></pre></form></td></tr>\n"); +} + +static void render_line_telnet(char type, const char *title, const char *host, const char *port) { + size_t indent = 0; + while (*title == ' ') { + title++; + indent++; + } + printf("<tr><td>%s</td><td><pre>%*s<a href=\"telnet://", icon(type), indent, ""); + if (host) { + print_htmlenc(host); + } + if (port && strcmp(port, "23")) { + putchar(':'); + print_htmlenc(port); + } + printf("\">"); + if (title) { + print_htmlenc(title); + } + printf("</a></pre></td></tr>\n"); +} + +static void render_line_href(char type, const char *title, const char *selector) { + size_t indent = 0; + while (*title == ' ') { + title++; + indent++; + } + printf("<tr><td>%s</td><td><pre>%*s<a href=\"", icon(type), indent, ""); + print_htmlenc(selector); + printf("\">"); + print_htmlenc(title); + printf("</a></pre></td></tr>\n"); +} + +static void render_line(char *line, size_t len) { + char type, *title, *selector, *host, *port; + if (len < 1) return; + line[len] = '\0'; + printf("<!--"); + print_htmlenc(line); + printf("-->\n"); + parse_line(line, &type, &title, &selector, &host, &port); + switch (type) { + case '0': + case '1': + case '5': + case '9': + case 'I': + case 'g': + case 's': + return render_line_link(type, title, selector, host, port); + case '7': + return render_line_search(type, title, selector, host, port); + case '8': + return render_line_telnet(type, title, host, port); + case 'h': + if (*selector == '/') selector++; + if (!strncmp(selector, "URL:", 4)) selector += 4; + return render_line_href(type, title, selector); + case 'i': + case '3': + return render_line_info(title); + case 'E': + return render_line_info(line); + case '.': + return render_line_empty(); + case '_': + return render_line_line(); + default: + return render_line_unknown(type, line); + } +} + +static void compact_buf(char *buf, size_t start, size_t end) { + size_t i; + for (i = start; i < end; i++) { + buf[i - start] = buf[i]; + } +} + +static size_t read_line(char *buf, size_t len) { + size_t i; + for (i = 0; i < len && buf[i] != '\r' && buf[i] != '\n'; i++); + if (buf[i] == '\r' || buf[i] == '\n') { + if (i+1 < len && buf[i+1] == '\n') i++; + render_line(buf, i); + return i+1; + } + return 0; +} + +static void read_response(int s) { + char buf[4096]; + size_t len; + size_t start = 0; + size_t end = 0; + int rc; + + while (1) { + /* fill up the buffer */ + len = sizeof(buf) - end; + rc = read_some(s, buf + end, &len); + if (rc < 0 && errno == EPIPE) break; + if (rc < 0) return warn("read_some"); + end += len; + /* read full lines */ + while ((len = read_line(buf + start, end - start))) start += len; + compact_buf(buf, start, end); + end -= start; + start = 0; + } + /* read the partial line */ + if (start < end) render_line(buf + start, end - start); + +} + +static void read_data(int s) { + char buf[4096]; + size_t len = sizeof(buf); + int rc; + while (1) { + rc = read_some(s, buf, &len); + if (rc < 0 && errno == EPIPE) return; + if (rc < 0) return warn("read response"); + rc = write_all(0, buf, len); + if (rc < 0) return warn("write response"); + } +} + +static void render_dir(int s, const char *url) { + dpi_send_header(url, "text/html"); + printf("<doctype html>"); + printf("<html><head><title>"); + print_htmlenc(url); + printf("</title></head><body><table>"); + read_response(s); + printf("</table></body></html>"); +} + +static void render_text(int s, const char *url) { + dpi_send_header(url, "text/plain"); + read_data(s); +} + +static void render_binary(int s, const char *url) { + // dpi_send_header(url, "application/octet-stream"); + dpi_send_header(url, "text/plain"); + read_data(s); +} + +static const char *detect_image_content_type(const char buf[4]) { + if (!strncmp(buf, "GIF8", 4)) return "image/gif"; + if (!strncmp(buf, "\x89PNG", 4)) return "image/png"; + if (!strncmp(buf, "\xff\xd8", 2)) return "image/jpeg"; + return "text/plain"; +} + +static void render_image(int s, const char *url) { + int rc; + char buf[4]; + rc = read_all(s, buf, sizeof(buf)); + if (rc < 0) return respond_err("read image"); + dpi_send_header(url, detect_image_content_type(buf)); + rc = write_all(0, buf, 4); + if (rc < 0) return warn("write image"); + read_data(s); +} + +static void fix_path(char *path) { + char *start, *end; + /* change form input name to query */ + start = strstr(path, "__gopher__query__="); + if (!start) return; + end = start + 18; + do *start++ = *end++; + while (*end); + if (start[-1] == '?') start--; + *start = '\0'; +} + +static void respond(const char *url) { + int rc; + const char *errstr = NULL; + char host[1024]; + char port[1024]; + char type; + char path[4096]; + int s; + rc = parse_url(url, host, sizeof(host), port, sizeof(port), &type, path, sizeof(path)); + if (rc < 0) return respond_err("parse_url"); + if (!*host) strcpy(host, "127.0.0.1"); + if (!*port) strcpy(port, "70"); + if (!type) type = '1'; + if (*path) fix_path(path); + s = tcp_connect(host, port, &errstr); + if (s < 0) return respond_errstr(errstr, "tcp_connect"); + rc = write_all(s, path, strlen(path)); + if (rc < 0) return respond_err("write request"); + rc = write_all(s, "\r\n", 2); + if (rc < 0) return respond_err("write request end"); + switch (type) { + case '1': return render_dir(s, url); + case '7': return render_dir(s, url); + case 'g': + case 'I': return render_image(s, url); + case '9': return render_binary(s, url); + default: return render_text(s, url); + } +} + +int main() { + char url[1024]; + setvbuf(stdout, NULL, _IONBF, BUFSIZ); + dpi_read_request(url, sizeof(url)); + respond(url); +} |