add about: fetcher

rename fetchers to be more sensible 

svn path=/trunk/netsurf/; revision=11692

1 files changed, 642 insertions, 0 deletions

diff --git a/content/fetchers/file.c b/content/fetchers/file.c
new file mode 100644
index 000000000..2f69fe583
--- /dev/null
+++ b/content/fetchers/file.c
@@ -0,0 +1,642 @@
+/*
+ * Copyright 2010 Vincent Sanders <vince@netsurf-browser.org>
+ *
+ * This file is part of NetSurf.
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* file: URL handling. Based on the data fetcher by Rob Kendrick */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <inttypes.h>
+#include <string.h>
+#include <strings.h>
+#include <time.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <limits.h>
+#include <stdarg.h>
+
+#include "utils/config.h"
+#include "content/dirlist.h"
+#include "content/fetch.h"
+#include "content/fetchers/file.h"
+#include "content/urldb.h"
+#include "desktop/netsurf.h"
+#include "desktop/options.h"
+#include "utils/log.h"
+#include "utils/messages.h"
+#include "utils/url.h"
+#include "utils/utils.h"
+#include "utils/ring.h"
+
+/* Maximum size of read buffer */
+#define FETCH_FILE_MAX_BUF_SIZE (1024 * 1024)
+
+/** Context for a fetch */
+struct fetch_file_context {
+	struct fetch_file_context *r_next, *r_prev;
+
+	struct fetch *fetchh; /**< Handle for this fetch */
+
+	bool aborted; /**< Flag indicating fetch has been aborted */
+	bool locked; /**< Flag indicating entry is already entered */
+
+	char *url; /**< The full url the fetch refers to */
+	char *path; /**< The actual path to be used with open() */
+
+	time_t file_etag; /**< Request etag for file (previous st.m_time) */
+};
+
+static struct fetch_file_context *ring = NULL;
+
+/** issue fetch callbacks with locking */
+static inline bool fetch_file_send_callback(fetch_msg msg,
+		struct fetch_file_context *ctx, const void *data,
+		unsigned long size, fetch_error_code errorcode)
+{
+	ctx->locked = true;
+	fetch_send_callback(msg, ctx->fetchh, data, size, errorcode);
+	ctx->locked = false;
+
+	return ctx->aborted;
+}
+
+static bool fetch_file_send_header(struct fetch_file_context *ctx,
+		const char *fmt, ...)
+{
+	char header[64];
+	va_list ap;
+
+	va_start(ap, fmt);
+
+	vsnprintf(header, sizeof header, fmt, ap);
+
+	va_end(ap);
+
+	fetch_file_send_callback(FETCH_HEADER, ctx, header, strlen(header), 
+			FETCH_ERROR_NO_ERROR);
+
+	return ctx->aborted;
+}
+
+/** callback to initialise the file fetcher. */
+static bool fetch_file_initialise(const char *scheme)
+{
+	return true;
+}
+
+/** callback to initialise the file fetcher. */
+static void fetch_file_finalise(const char *scheme)
+{
+}
+
+/** callback to set up a file fetch context. */
+static void *
+fetch_file_setup(struct fetch *fetchh,
+		 const char *url,
+		 bool only_2xx,
+		 const char *post_urlenc,
+		 const struct fetch_multipart_data *post_multipart,
+		 const char **headers)
+{
+	struct fetch_file_context *ctx;
+	int i;
+
+	ctx = calloc(1, sizeof(*ctx));
+	if (ctx == NULL)
+		return NULL;
+
+	ctx->path = url_to_path(url);
+	if (ctx->path == NULL) {
+		free(ctx);
+		return NULL;
+	}
+
+	ctx->url = strdup(url);
+	if (ctx->url == NULL) {
+		free(ctx->path);
+		free(ctx);
+		return NULL;
+	}
+
+	/* Scan request headers looking for If-None-Match */
+	for (i = 0; headers[i] != NULL; i++) {
+		if (strncasecmp(headers[i], "If-None-Match:", 
+				SLEN("If-None-Match:")) == 0) {
+			/* If-None-Match: "12345678" */
+			const char *d = headers[i] + SLEN("If-None-Match:");
+
+			/* Scan to first digit, if any */
+			while (*d != '\0' && (*d < '0' || '9' < *d))
+				d++;
+
+			/* Convert to time_t */
+			if (*d != '\0')
+				ctx->file_etag = atoi(d);
+		}
+	}
+
+	ctx->fetchh = fetchh;
+
+	RING_INSERT(ring, ctx);
+
+	return ctx;
+}
+
+/** callback to free a file fetch */
+static void fetch_file_free(void *ctx)
+{
+	struct fetch_file_context *c = ctx;
+	free(c->url);
+	free(c->path);
+	RING_REMOVE(ring, c);
+	free(ctx);
+}
+
+/** callback to start a file fetch */
+static bool fetch_file_start(void *ctx)
+{
+	return true;
+}
+
+/** callback to abort a file fetch */
+static void fetch_file_abort(void *ctx)
+{
+	struct fetch_file_context *c = ctx;
+
+	/* To avoid the poll loop having to deal with the fetch context
+	 * disappearing from under it, we simply flag the abort here.
+	 * The poll loop itself will perform the appropriate cleanup.
+	 */
+	c->aborted = true;
+}
+
+static int fetch_file_errno_to_http_code(int error_no)
+{
+	switch (error_no) {
+	case ENAMETOOLONG:
+		return 400;
+	case EACCES:
+		return 403;
+	case ENOENT:
+		return 404;
+	default:
+		break;
+	}
+
+	return 500;
+}
+
+static void fetch_file_process_error(struct fetch_file_context *ctx, int code)
+{
+	char buffer[1024];
+	const char *title;
+	char key[8];
+
+	/* content is going to return error code */
+	fetch_set_http_code(ctx->fetchh, code);
+
+	/* content type */
+	if (fetch_file_send_header(ctx, "Content-Type: text/html"))
+		goto fetch_file_process_error_aborted;
+
+	snprintf(key, sizeof key, "HTTP%03d", code);
+	title = messages_get(key);
+
+	snprintf(buffer, sizeof buffer, "<html><head><title>%s</title></head>"
+			"<body><h1>%s</h1>"
+			"<p>Error %d while fetching file %s</p></body></html>",
+			title, title, code, ctx->url);
+
+	if (fetch_file_send_callback(FETCH_DATA, ctx, buffer, strlen(buffer), 
+			FETCH_ERROR_NO_ERROR))
+		goto fetch_file_process_error_aborted;
+
+	fetch_file_send_callback(FETCH_FINISHED, ctx, 0, 0, 
+			FETCH_ERROR_NO_ERROR);
+
+fetch_file_process_error_aborted:
+	return;
+}
+
+
+/** Process object as a regular file */
+static void fetch_file_process_plain(struct fetch_file_context *ctx,
+				     struct stat *fdstat)
+{
+	char *buf;
+	size_t buf_size;
+
+	ssize_t tot_read = 0;
+	ssize_t res;
+
+	int fd; /**< The file descriptor of the object */
+
+	/* Check if we can just return not modified */
+	if (ctx->file_etag != 0 && ctx->file_etag == fdstat->st_mtime) {
+		fetch_set_http_code(ctx->fetchh, 304);
+		fetch_file_send_callback(FETCH_NOTMODIFIED, ctx, 0, 0,
+				FETCH_ERROR_NO_ERROR);
+		return;
+	}
+
+	fd = open(ctx->path, O_RDONLY);
+	if (fd < 0) {
+		/* process errors as appropriate */
+		fetch_file_process_error(ctx,
+				fetch_file_errno_to_http_code(errno));
+		return;
+	}
+
+	/* set buffer size */
+	buf_size = fdstat->st_size;
+	if (buf_size > FETCH_FILE_MAX_BUF_SIZE)
+		buf_size = FETCH_FILE_MAX_BUF_SIZE;
+
+	/* allocate the buffer storage */
+	buf = malloc(buf_size);
+	if (buf == NULL) {
+		fetch_file_send_callback(FETCH_ERROR, ctx,
+			"Unable to allocate memory for file data buffer",
+			0, FETCH_ERROR_MEMORY);
+		close(fd);
+		return;
+	}
+
+	/* fetch is going to be successful */
+	fetch_set_http_code(ctx->fetchh, 200);
+
+	/* Any callback can result in the fetch being aborted.
+	 * Therefore, we _must_ check for this after _every_ call to
+	 * fetch_file_send_callback().
+	 */
+
+	/* content type */
+	if (fetch_file_send_header(ctx, "Content-Type: %s", 
+			fetch_filetype(ctx->path)))
+		goto fetch_file_process_aborted;
+
+	/* content length */
+	if (fetch_file_send_header(ctx, "Content-Length: %zd", fdstat->st_size))
+		goto fetch_file_process_aborted;
+
+	/* create etag */
+	if (fetch_file_send_header(ctx, "ETag: \"%10" PRId64 "\"", 
+			(int64_t) fdstat->st_mtime))
+		goto fetch_file_process_aborted;
+
+	/* main data loop */
+	do {
+		res = read(fd, buf, buf_size);
+		if (res == -1) {
+			fetch_file_send_callback(FETCH_ERROR, ctx, 
+					"Error reading file", 0, 
+					FETCH_ERROR_PARTIAL_FILE);
+			goto fetch_file_process_aborted;
+		}
+
+		if (res == 0) {
+			fetch_file_send_callback(FETCH_ERROR, ctx, 
+					"Unexpected EOF reading file", 0, 
+					FETCH_ERROR_PARTIAL_FILE);
+			goto fetch_file_process_aborted;
+		}
+
+		tot_read += res;
+
+		if (fetch_file_send_callback(FETCH_DATA, ctx, buf, res, 
+				FETCH_ERROR_NO_ERROR))
+			break;
+
+	} while (tot_read < fdstat->st_size);
+
+	if (ctx->aborted == false)
+		fetch_file_send_callback(FETCH_FINISHED, ctx, 0, 0, 
+				FETCH_ERROR_NO_ERROR);
+
+fetch_file_process_aborted:
+
+	close(fd);
+	free(buf);
+	return;
+}
+
+static char *gen_nice_title(char *path)
+{
+	char *nice_path, *cnv, *tmp;
+	char *title;
+	int title_length;
+
+	/* Convert path for display */
+	nice_path = malloc(strlen(path) * SLEN("&amp;") + 1);
+	if (nice_path == NULL) {
+		return NULL;
+	}
+
+	/* Escape special HTML characters */
+	for (cnv = nice_path, tmp = path; *tmp != '\0'; tmp++) {
+		if (*tmp == '<') {
+			*cnv++ = '&';
+			*cnv++ = 'l';
+			*cnv++ = 't';
+			*cnv++ = ';';
+		} else if (*tmp == '>') {
+			*cnv++ = '&';
+			*cnv++ = 'g';
+			*cnv++ = 't';
+			*cnv++ = ';';
+		} else if (*tmp == '&') {
+			*cnv++ = '&';
+			*cnv++ = 'a';
+			*cnv++ = 'm';
+			*cnv++ = 'p';
+			*cnv++ = ';';
+		} else {
+			*cnv++ = *tmp;
+		}
+	}
+	*cnv = '\0';
+
+	/* Construct a localised title string */
+	title_length = (cnv - nice_path) + strlen(messages_get("FileIndex"));
+	title = malloc(title_length + 1);
+
+	if (title == NULL) {
+		free(nice_path);
+		return NULL;
+	}
+
+	/* Set title to localised "Index of <nice_path>" */
+	snprintf(title, title_length, messages_get("FileIndex"), nice_path);
+
+	free(nice_path);
+
+	return title;
+}
+
+
+static void fetch_file_process_dir(struct fetch_file_context *ctx,
+				   struct stat *fdstat)
+{
+	char buffer[1024]; /* Output buffer */
+	bool even = false; /* formatting flag */
+	char *title; /* pretty printed title */
+	url_func_result res; /* result from url routines */
+	char *up; /* url of parent */
+	char *path; /* url for list entries */
+	bool compare; /* result of url compare */
+
+	DIR *scandir; /* handle for enumerating the directory */
+	struct dirent* ent; /* leaf directory entry */
+	struct stat ent_stat; /* stat result of leaf entry */
+	char datebuf[64]; /* buffer for date text */
+	char timebuf[64]; /* buffer for time text */
+	char urlpath[PATH_MAX]; /* buffer for leaf entry path */
+
+	scandir = opendir(ctx->path);
+	if (scandir == NULL) {
+		fetch_file_process_error(ctx,
+			fetch_file_errno_to_http_code(errno));
+		return;
+	}
+
+	/* fetch is going to be successful */
+	fetch_set_http_code(ctx->fetchh, 200);
+
+	/* force no-cache */
+	if (fetch_file_send_header(ctx, "Cache-Control: no-cache"))
+		goto fetch_file_process_dir_aborted;
+
+	/* content type */
+	if (fetch_file_send_header(ctx, "Content-Type: text/html"))
+		goto fetch_file_process_dir_aborted;
+
+	/* directory listing top */
+	dirlist_generate_top(buffer, sizeof buffer);
+	if (fetch_file_send_callback(FETCH_DATA, ctx, buffer, strlen(buffer), 
+			FETCH_ERROR_NO_ERROR))
+		goto fetch_file_process_dir_aborted;
+
+	/* directory listing title */
+	title = gen_nice_title(ctx->path);
+	dirlist_generate_title(title, buffer, sizeof buffer);
+	free(title);
+	if (fetch_file_send_callback(FETCH_DATA, ctx, buffer, strlen(buffer), 
+			FETCH_ERROR_NO_ERROR))
+		goto fetch_file_process_dir_aborted;
+
+	/* Print parent directory link */
+	res = url_parent(ctx->url, &up);
+	if (res == URL_FUNC_OK) {
+		res = url_compare(ctx->url, up, false, &compare);
+		if ((res == URL_FUNC_OK) && compare == false) {
+			dirlist_generate_parent_link(up, buffer, sizeof buffer);
+
+			fetch_file_send_callback(FETCH_DATA, ctx,
+						 buffer,
+						 strlen(buffer),
+						 FETCH_ERROR_NO_ERROR);
+
+		}
+		free(up);
+
+		if (ctx->aborted)
+			goto fetch_file_process_dir_aborted;
+
+	}
+
+	/* directory list headings */
+	dirlist_generate_headings(buffer, sizeof buffer);
+	if (fetch_file_send_callback(FETCH_DATA, ctx, buffer, strlen(buffer), 
+			FETCH_ERROR_NO_ERROR))
+		goto fetch_file_process_dir_aborted;
+
+	while ((ent = readdir(scandir)) != NULL) {
+
+		if (ent->d_name[0] == '.')
+			continue;
+
+		strncpy(urlpath, ctx->path, sizeof urlpath);
+		if (path_add_part(urlpath, sizeof urlpath, 
+				ent->d_name) == false)
+			continue;
+
+		if (stat(urlpath, &ent_stat) != 0) {
+			ent_stat.st_mode = 0;
+			datebuf[0] = 0;
+			timebuf[0] = 0;
+		} else {
+			/* Get date in output format */
+			if (strftime((char *)&datebuf, sizeof datebuf,
+				     "%a %d %b %Y",
+				     localtime(&ent_stat.st_mtime)) == 0) {
+				strncpy(datebuf, "-", sizeof datebuf);
+			}
+
+			/* Get time in output format */
+			if (strftime((char *)&timebuf, sizeof timebuf,
+				     "%H:%M",
+				     localtime(&ent_stat.st_mtime)) == 0) {
+				strncpy(timebuf, "-", sizeof timebuf);
+			}
+		}
+
+		if((path = path_to_url(urlpath)) == NULL)
+			continue;
+
+		if (S_ISREG(ent_stat.st_mode)) {
+			/* regular file */
+			dirlist_generate_row(even,
+					     false,
+					     path,
+					     ent->d_name,
+					     fetch_filetype(urlpath),
+					     ent_stat.st_size,
+					     datebuf, timebuf,
+					     buffer, sizeof(buffer));
+		} else if (S_ISDIR(ent_stat.st_mode)) {
+			/* directory */
+			dirlist_generate_row(even,
+					     true,
+					     path,
+					     ent->d_name,
+					     messages_get("FileDirectory"),
+					     -1,
+					     datebuf, timebuf,
+					     buffer, sizeof(buffer));
+		} else {
+			/* something else */
+			dirlist_generate_row(even,
+					     false,
+					     path,
+					     ent->d_name,
+					     "",
+					     -1,
+					     datebuf, timebuf,
+					     buffer, sizeof(buffer));
+		}
+
+		free(path);
+
+		if (fetch_file_send_callback(FETCH_DATA, ctx,
+					     buffer,
+					     strlen(buffer),
+					     FETCH_ERROR_NO_ERROR))
+			goto fetch_file_process_dir_aborted;
+
+		even = !even;
+	}
+
+	/* directory listing bottom */
+	dirlist_generate_bottom(buffer, sizeof buffer);
+	if (fetch_file_send_callback(FETCH_DATA, ctx, buffer, strlen(buffer), 
+			FETCH_ERROR_NO_ERROR))
+		goto fetch_file_process_dir_aborted;
+
+
+	fetch_file_send_callback(FETCH_FINISHED, ctx, 0, 0, 
+			FETCH_ERROR_NO_ERROR);
+
+fetch_file_process_dir_aborted:
+
+	closedir(scandir);
+}
+
+
+/* process a file fetch */
+static void fetch_file_process(struct fetch_file_context *ctx)
+{
+	struct stat fdstat; /**< The objects stat */
+
+	if (stat(ctx->path, &fdstat) != 0) {
+		/* process errors as appropriate */
+		fetch_file_process_error(ctx,
+				fetch_file_errno_to_http_code(errno));
+		return;
+	}
+
+	if (S_ISDIR(fdstat.st_mode)) {
+		/* directory listing */
+		fetch_file_process_dir(ctx, &fdstat);
+		return;
+	} else if (S_ISREG(fdstat.st_mode)) {
+		/* regular file */
+		fetch_file_process_plain(ctx, &fdstat);
+		return;
+	} else {
+		/* unhandled type of file */
+		fetch_file_process_error(ctx, 501);
+	}
+
+	return;
+}
+
+/** callback to poll for additional file fetch contents */
+static void fetch_file_poll(const char *scheme)
+{
+	struct fetch_file_context *c, *next;
+
+	if (ring == NULL) return;
+
+	/* Iterate over ring, processing each pending fetch */
+	c = ring;
+	do {
+		/* Take a copy of the next pointer as we may destroy
+		 * the ring item we're currently processing */
+		next = c->r_next;
+
+		/* Ignore fetches that have been flagged as locked.
+		 * This allows safe re-entrant calls to this function.
+		 * Re-entrancy can occur if, as a result of a callback,
+		 * the interested party causes fetch_poll() to be called
+		 * again.
+		 */
+		if (c->locked == true) {
+			continue;
+		}
+
+		/* Only process non-aborted fetches */
+		if (c->aborted == false) {
+			/* file fetches can be processed in one go */
+			fetch_file_process(c);
+		}
+
+
+		fetch_remove_from_queues(c->fetchh);
+		fetch_free(c->fetchh);
+
+		/* Advance to next ring entry, exiting if we've reached
+		 * the start of the ring or the ring has become empty
+		 */
+	} while ( (c = next) != ring && ring != NULL);
+}
+
+void fetch_file_register(void)
+{
+	fetch_add_fetcher("file",
+		fetch_file_initialise,
+		fetch_file_setup,
+		fetch_file_start,
+		fetch_file_abort,
+		fetch_file_free,
+		fetch_file_poll,
+		fetch_file_finalise);
+}