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-rw-r--r--content/fetchers/file/file.c844
1 files changed, 844 insertions, 0 deletions
diff --git a/content/fetchers/file/file.c b/content/fetchers/file/file.c
new file mode 100644
index 000000000..ff3a1b1f6
--- /dev/null
+++ b/content/fetchers/file/file.c
@@ -0,0 +1,844 @@
+/*
+ * 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
+ *
+ * file scheme URL handling. Based on the data fetcher by Rob Kendrick
+ *
+ * output dates and directory ordering are affected by the current locale
+ */
+
+#include "utils/config.h"
+
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+#include <strings.h>
+#include <time.h>
+#include <stdio.h>
+#include <stdarg.h>
+#ifdef HAVE_MMAP
+#include <sys/mman.h>
+#endif
+#include <libwapcaplet/libwapcaplet.h>
+
+#include "netsurf/inttypes.h"
+#include "utils/nsurl.h"
+#include "utils/dirent.h"
+#include "utils/corestrings.h"
+#include "utils/messages.h"
+#include "utils/utils.h"
+#include "utils/log.h"
+#include "utils/time.h"
+#include "utils/ring.h"
+#include "utils/file.h"
+#include "netsurf/fetch.h"
+#include "desktop/gui_internal.h"
+
+#include "content/fetch.h"
+#include "content/fetchers.h"
+#include "dirlist.h"
+#include "file.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 */
+
+ nsurl *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(const fetch_msg *msg,
+ struct fetch_file_context *ctx)
+{
+ ctx->locked = true;
+ fetch_send_callback(msg, ctx->fetchh);
+ ctx->locked = false;
+
+ return ctx->aborted;
+}
+
+static bool fetch_file_send_header(struct fetch_file_context *ctx,
+ const char *fmt, ...)
+{
+ fetch_msg msg;
+ char header[64];
+ va_list ap;
+ int len;
+
+ va_start(ap, fmt);
+ len = vsnprintf(header, sizeof header, fmt, ap);
+ va_end(ap);
+
+ if (len >= (int)sizeof(header) || len < 0) {
+ return false;
+ }
+
+ msg.type = FETCH_HEADER;
+ msg.data.header_or_data.buf = (const uint8_t *) header;
+ msg.data.header_or_data.len = len;
+
+ return fetch_file_send_callback(&msg, ctx);
+}
+
+/** callback to initialise the file fetcher. */
+static bool fetch_file_initialise(lwc_string *scheme)
+{
+ return true;
+}
+
+/** callback to initialise the file fetcher. */
+static void fetch_file_finalise(lwc_string *scheme)
+{
+}
+
+static bool fetch_file_can_fetch(const nsurl *url)
+{
+ return true;
+}
+
+/** callback to set up a file fetch context. */
+static void *
+fetch_file_setup(struct fetch *fetchh,
+ nsurl *url,
+ bool only_2xx,
+ bool downgrade_tls,
+ const char *post_urlenc,
+ const struct fetch_multipart_data *post_multipart,
+ const char **headers)
+{
+ struct fetch_file_context *ctx;
+ int i;
+ nserror ret;
+
+ ctx = calloc(1, sizeof(*ctx));
+ if (ctx == NULL)
+ return NULL;
+
+ ret = guit->file->nsurl_to_path(url, &ctx->path);
+ if (ret != NSERROR_OK) {
+ free(ctx);
+ return NULL;
+ }
+
+ ctx->url = nsurl_ref(url);
+
+ /* 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) {
+ continue;
+ }
+
+ /* 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') {
+ ret = nsc_snptimet(d, strlen(d), &ctx->file_etag);
+ if (ret != NSERROR_OK) {
+ NSLOG(fetch, WARNING,
+ "Bad If-None-Match value");
+ }
+ }
+ }
+
+ 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;
+ nsurl_unref(c->url);
+ free(c->path);
+ 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)
+{
+ fetch_msg msg;
+ 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, nsurl_access(ctx->url));
+
+ msg.type = FETCH_DATA;
+ msg.data.header_or_data.buf = (const uint8_t *) buffer;
+ msg.data.header_or_data.len = strlen(buffer);
+ if (fetch_file_send_callback(&msg, ctx))
+ goto fetch_file_process_error_aborted;
+
+ msg.type = FETCH_FINISHED;
+ fetch_file_send_callback(&msg, ctx);
+
+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)
+{
+#ifdef HAVE_MMAP
+ fetch_msg msg;
+ char *buf = NULL;
+ size_t buf_size;
+
+ 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);
+ msg.type = FETCH_NOTMODIFIED;
+ fetch_file_send_callback(&msg, ctx);
+ 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;
+
+ /* allocate the buffer storage */
+ if (buf_size > 0) {
+ buf = mmap(NULL, buf_size, PROT_READ, MAP_SHARED, fd, 0);
+ if (buf == MAP_FAILED) {
+ msg.type = FETCH_ERROR;
+ msg.data.error = "Unable to map memory for file data buffer";
+ fetch_file_send_callback(&msg, ctx);
+ 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",
+ guit->fetch->filetype(ctx->path))) {
+ goto fetch_file_process_aborted;
+ }
+
+ /* content length */
+ if (fetch_file_send_header(ctx, "Content-Length: %" PRIsizet,
+ 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;
+ }
+
+ msg.type = FETCH_DATA;
+ msg.data.header_or_data.buf = (const uint8_t *) buf;
+ msg.data.header_or_data.len = buf_size;
+ fetch_file_send_callback(&msg, ctx);
+
+ if (ctx->aborted == false) {
+ msg.type = FETCH_FINISHED;
+ fetch_file_send_callback(&msg, ctx);
+ }
+
+fetch_file_process_aborted:
+
+ if (buf != NULL)
+ munmap(buf, buf_size);
+ close(fd);
+#else
+ fetch_msg msg;
+ char *buf;
+ size_t buf_size;
+
+ ssize_t tot_read = 0;
+ ssize_t res;
+
+ FILE *infile;
+
+ /* 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);
+ msg.type = FETCH_NOTMODIFIED;
+ fetch_file_send_callback(&msg, ctx);
+ return;
+ }
+
+ infile = fopen(ctx->path, "rb");
+ if (infile == NULL) {
+ /* 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) {
+ msg.type = FETCH_ERROR;
+ msg.data.error =
+ "Unable to allocate memory for file data buffer";
+ fetch_file_send_callback(&msg, ctx);
+ fclose(infile);
+ 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",
+ guit->fetch->filetype(ctx->path))) {
+ goto fetch_file_process_aborted;
+ }
+
+ /* content length */
+ if (fetch_file_send_header(ctx, "Content-Length: %" PRIsizet,
+ 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 */
+ while (tot_read < fdstat->st_size) {
+ res = fread(buf, 1, buf_size, infile);
+ if (res == 0) {
+ if (feof(infile)) {
+ msg.type = FETCH_ERROR;
+ msg.data.error = "Unexpected EOF reading file";
+ fetch_file_send_callback(&msg, ctx);
+ goto fetch_file_process_aborted;
+ } else {
+ msg.type = FETCH_ERROR;
+ msg.data.error = "Error reading file";
+ fetch_file_send_callback(&msg, ctx);
+ goto fetch_file_process_aborted;
+ }
+ }
+ tot_read += res;
+
+ msg.type = FETCH_DATA;
+ msg.data.header_or_data.buf = (const uint8_t *) buf;
+ msg.data.header_or_data.len = res;
+ if (fetch_file_send_callback(&msg, ctx))
+ break;
+ }
+
+ if (ctx->aborted == false) {
+ msg.type = FETCH_FINISHED;
+ fetch_file_send_callback(&msg, ctx);
+ }
+
+fetch_file_process_aborted:
+
+ fclose(infile);
+ free(buf);
+#endif
+ 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;
+}
+
+/**
+ * Generate an output row of the directory listing.
+ *
+ * \param ctx The file fetching context.
+ * \param ent current directory entry.
+ * \param even is the row an even row.
+ * \param buffer The output buffer.
+ * \param buffer_len The space available in the output buffer.
+ * \return NSERROR_OK or error code on faliure.
+ */
+static nserror
+process_dir_ent(struct fetch_file_context *ctx,
+ struct dirent *ent,
+ bool even,
+ char *buffer,
+ size_t buffer_len)
+{
+ nserror ret;
+ char *urlpath = NULL; /* buffer for leaf entry path */
+ struct stat ent_stat; /* stat result of leaf entry */
+ char datebuf[64]; /* buffer for date text */
+ char timebuf[64]; /* buffer for time text */
+ nsurl *url;
+
+ /* skip hidden files */
+ if (ent->d_name[0] == '.') {
+ return NSERROR_BAD_PARAMETER;
+ }
+
+ ret = netsurf_mkpath(&urlpath, NULL, 2, ctx->path, ent->d_name);
+ if (ret != NSERROR_OK) {
+ return ret;
+ }
+
+ if (stat(urlpath, &ent_stat) != 0) {
+ ent_stat.st_mode = 0;
+ datebuf[0] = 0;
+ timebuf[0] = 0;
+ } else {
+ /* Get date in output format. a (day of week) and b
+ * (month) are both affected by the locale
+ */
+ if (strftime((char *)&datebuf, sizeof datebuf, "%a %d %b %Y",
+ localtime(&ent_stat.st_mtime)) == 0) {
+ datebuf[0] = '-';
+ datebuf[1] = 0;
+ }
+
+ /* Get time in output format */
+ if (strftime((char *)&timebuf, sizeof timebuf, "%H:%M",
+ localtime(&ent_stat.st_mtime)) == 0) {
+ timebuf[0] = '-';
+ timebuf[1] = 0;
+ }
+ }
+
+ ret = guit->file->path_to_nsurl(urlpath, &url);
+ if (ret != NSERROR_OK) {
+ free(urlpath);
+ return ret;
+ }
+
+ if (S_ISREG(ent_stat.st_mode)) {
+ /* regular file */
+ dirlist_generate_row(even,
+ false,
+ url,
+ ent->d_name,
+ guit->fetch->filetype(urlpath),
+ ent_stat.st_size,
+ datebuf, timebuf,
+ buffer, buffer_len);
+ } else if (S_ISDIR(ent_stat.st_mode)) {
+ /* directory */
+ dirlist_generate_row(even,
+ true,
+ url,
+ ent->d_name,
+ messages_get("FileDirectory"),
+ -1,
+ datebuf, timebuf,
+ buffer, buffer_len);
+ } else {
+ /* something else */
+ dirlist_generate_row(even,
+ false,
+ url,
+ ent->d_name,
+ "",
+ -1,
+ datebuf, timebuf,
+ buffer, buffer_len);
+ }
+
+ nsurl_unref(url);
+ free(urlpath);
+
+ return NSERROR_OK;
+}
+
+/**
+ * Comparison function for sorting directories.
+ *
+ * Correctly orders non zero-padded numerical parts.
+ * ie. produces "file1, file2, file10" rather than "file1, file10, file2".
+ *
+ * \param d1 first directory entry
+ * \param d2 second directory entry
+ */
+static int dir_sort_alpha(const struct dirent **d1, const struct dirent **d2)
+{
+ const char *s1 = (*d1)->d_name;
+ const char *s2 = (*d2)->d_name;
+
+ while (*s1 != '\0' && *s2 != '\0') {
+ if ((*s1 >= '0' && *s1 <= '9') &&
+ (*s2 >= '0' && *s2 <= '9')) {
+ int n1 = 0, n2 = 0;
+ while (*s1 >= '0' && *s1 <= '9') {
+ n1 = n1 * 10 + (*s1) - '0';
+ s1++;
+ }
+ while (*s2 >= '0' && *s2 <= '9') {
+ n2 = n2 * 10 + (*s2) - '0';
+ s2++;
+ }
+ if (n1 != n2) {
+ return n1 - n2;
+ }
+ if (*s1 == '\0' || *s2 == '\0')
+ break;
+ }
+ if (tolower(*s1) != tolower(*s2))
+ break;
+
+ s1++;
+ s2++;
+ }
+
+ return tolower(*s1) - tolower(*s2);
+}
+
+static void fetch_file_process_dir(struct fetch_file_context *ctx,
+ struct stat *fdstat)
+{
+ fetch_msg msg;
+ char buffer[1024]; /* Output buffer */
+ bool even = false; /* formatting flag */
+ char *title; /* pretty printed title */
+ nserror err; /* result from url routines */
+ nsurl *up; /* url of parent */
+
+ struct dirent **listing = NULL; /* directory entry listing */
+ int i; /* directory entry index */
+ int n; /* number of directory entries */
+
+ n = scandir(ctx->path, &listing, 0, dir_sort_alpha);
+ if (n < 0) {
+ 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;
+
+ msg.type = FETCH_DATA;
+ msg.data.header_or_data.buf = (const uint8_t *) buffer;
+
+ /* directory listing top */
+ dirlist_generate_top(buffer, sizeof buffer);
+ msg.data.header_or_data.len = strlen(buffer);
+ if (fetch_file_send_callback(&msg, ctx))
+ goto fetch_file_process_dir_aborted;
+
+ /* directory listing title */
+ title = gen_nice_title(ctx->path);
+ dirlist_generate_title(title, buffer, sizeof buffer);
+ free(title);
+ msg.data.header_or_data.len = strlen(buffer);
+ if (fetch_file_send_callback(&msg, ctx))
+ goto fetch_file_process_dir_aborted;
+
+ /* Print parent directory link */
+ err = nsurl_parent(ctx->url, &up);
+ if (err == NSERROR_OK) {
+ if (nsurl_compare(ctx->url, up, NSURL_COMPLETE) == false) {
+ /* different URL; have parent */
+ dirlist_generate_parent_link(nsurl_access(up),
+ buffer, sizeof buffer);
+
+ msg.data.header_or_data.len = strlen(buffer);
+ fetch_file_send_callback(&msg, ctx);
+ }
+ nsurl_unref(up);
+
+ if (ctx->aborted)
+ goto fetch_file_process_dir_aborted;
+
+ }
+
+ /* directory list headings */
+ dirlist_generate_headings(buffer, sizeof buffer);
+ msg.data.header_or_data.len = strlen(buffer);
+ if (fetch_file_send_callback(&msg, ctx))
+ goto fetch_file_process_dir_aborted;
+
+ for (i = 0; i < n; i++) {
+
+ err = process_dir_ent(ctx, listing[i], even, buffer,
+ sizeof(buffer));
+
+ if (err == NSERROR_OK) {
+ msg.data.header_or_data.len = strlen(buffer);
+ if (fetch_file_send_callback(&msg, ctx))
+ goto fetch_file_process_dir_aborted;
+
+ even = !even;
+ }
+ }
+
+ /* directory listing bottom */
+ dirlist_generate_bottom(buffer, sizeof buffer);
+ msg.data.header_or_data.len = strlen(buffer);
+ if (fetch_file_send_callback(&msg, ctx))
+ goto fetch_file_process_dir_aborted;
+
+ msg.type = FETCH_FINISHED;
+ fetch_file_send_callback(&msg, ctx);
+
+fetch_file_process_dir_aborted:
+
+ if (listing != NULL) {
+ for (i = 0; i < n; i++) {
+ free(listing[i]);
+ }
+ free(listing);
+ }
+}
+
+
+/* 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(lwc_string *scheme)
+{
+ struct fetch_file_context *c, *save_ring = NULL;
+
+ while (ring != NULL) {
+ /* Take the first entry from the ring */
+ c = ring;
+ RING_REMOVE(ring, c);
+
+ /* 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) {
+ RING_INSERT(save_ring, c);
+ continue;
+ }
+
+ /* Only process non-aborted fetches */
+ if (c->aborted == false) {
+ /* file fetches can be processed in one go */
+ fetch_file_process(c);
+ }
+
+ /* And now finish */
+ fetch_remove_from_queues(c->fetchh);
+ fetch_free(c->fetchh);
+
+ }
+
+ /* Finally, if we saved any fetches which were locked, put them back
+ * into the ring for next time
+ */
+ ring = save_ring;
+}
+
+nserror fetch_file_register(void)
+{
+ lwc_string *scheme = lwc_string_ref(corestring_lwc_file);
+ const struct fetcher_operation_table fetcher_ops = {
+ .initialise = fetch_file_initialise,
+ .acceptable = fetch_file_can_fetch,
+ .setup = fetch_file_setup,
+ .start = fetch_file_start,
+ .abort = fetch_file_abort,
+ .free = fetch_file_free,
+ .poll = fetch_file_poll,
+ .finalise = fetch_file_finalise
+ };
+
+ return fetcher_add(scheme, &fetcher_ops);
+}