| Message ID | 20200727121457.7500-1-josef@pex.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [FFmpeg-devel,v2,1/2] avformat/url: fix logic for removing ".." path components | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/make | success | Make finished |
| andriy/make_fate | success | Make fate finished |
Josef Zlomek <josef@pex.com> 于2020年7月27日周一 下午8:15写道： > > Fixes: 8814 > > The logic for removing ".." path components and their corresponding > upper directories was reworked. > > Now, the function trim_double_dot_url splits the path by "/" into > components, and processes the components one ny one: > - if the component is "..", the last path component in tmp_path is removed > - if the component is not empty, it is added to tmp_path > > The duplicate logic was removed from ff_make_absolute_url. > > Signed-off-by: Josef Zlomek <josef@pex.com> > --- > libavformat/url.c | 90 ++++++++++++++++++++++------------------------- > 1 file changed, 43 insertions(+), 47 deletions(-) > > diff --git a/libavformat/url.c b/libavformat/url.c > index 20463a6674..343cbca9b9 100644 > --- a/libavformat/url.c > +++ b/libavformat/url.c > @@ -83,8 +83,10 @@ static void trim_double_dot_url(char *buf, const char *rel, int size) > const char *p = rel; > const char *root = rel; > char tmp_path[MAX_URL_SIZE] = {0, }; > - char *sep; > - char *node; > + int tmp_len = 0; > + const char *sep; > + const char *next; > + int last_is_dir; > > /* Get the path root of the url which start by "://" */ > if (p && (sep = strstr(p, "://"))) { > @@ -93,29 +95,45 @@ static void trim_double_dot_url(char *buf, const char *rel, int size) > if (!root) > return; > } > + if (*root == '/') > + ++root; > + > + /* Split the path by "/" and remove ".." and its corresponding directory. */ > + last_is_dir = 1; > + for (p = root; *p; p = next) { > + next = strchr(p, '/'); > + if (!next) { > + next = p + strlen(p); > + last_is_dir = 0; > + } > > - /* set new current position if the root node is changed */ > - p = root; > - while (p && (node = strstr(p, ".."))) { > - av_strlcat(tmp_path, p, node - p + strlen(tmp_path)); > - p = node + 3; > - sep = strrchr(tmp_path, '/'); > - if (sep) > - sep[0] = '\0'; > - else > - tmp_path[0] = '\0'; > - } > + if (next - p == 2 && !strncmp(p, "..", 2)) { > + /* remove the last directory from tmp_path */ > + while (tmp_len > 0 && tmp_path[--tmp_len] != '/') > + ; > + tmp_path[tmp_len] = '\0'; > + last_is_dir = 1; > + } else if (next > p) { > + /* copy the current path component to tmp_path (including '/') */ > + if (tmp_len) { > + av_strlcpy(tmp_path + tmp_len, "/", sizeof(tmp_path) - tmp_len); > + ++tmp_len; > + } > + av_strlcpy(tmp_path + tmp_len, p, FFMIN(sizeof(tmp_path) - tmp_len, > + next - p + 1)); > + tmp_len += next - p; > + tmp_path[tmp_len] = '\0'; > + } > > - if (!av_stristart(p, "/", NULL) && root != rel) > - av_strlcat(tmp_path, "/", size); > + /* skip "/" */ > + while (*next == '/') > + ++next; > + } > + if (last_is_dir && tmp_len) > + av_strlcpy(tmp_path + tmp_len, "/", sizeof(tmp_path) - tmp_len); > > - av_strlcat(tmp_path, p, size); > /* start set buf after temp path process. */ > av_strlcpy(buf, rel, root - rel + 1); > - > - if (!av_stristart(tmp_path, "/", NULL) && root != rel) > - av_strlcat(buf, "/", size); > - > av_strlcat(buf, tmp_path, size); > } > > @@ -175,14 +193,11 @@ void ff_make_absolute_url(char *buf, int size, const char *base, > > root = p = buf; > /* Get the path root of the url which start by "://" */ > - if (p && strstr(p, "://")) { > - sep = strstr(p, "://"); > - if (sep) { > - sep += 3; > - root = strchr(sep, '/'); > - if (!root) > - return; > - } > + if (p && (sep = strstr(p, "://"))) { > + sep += 3; > + root = strchr(sep, '/'); > + if (!root) > + return; > } > > /* Remove the file name from the base url */ > @@ -194,26 +209,7 @@ void ff_make_absolute_url(char *buf, int size, const char *base, > sep[1] = '\0'; > else > buf[0] = '\0'; > - while (av_strstart(rel, "..", NULL) && sep) { > - /* Remove the path delimiter at the end */ > - if (sep > root) { > - sep[0] = '\0'; > - sep = strrchr(buf, '/'); > - } > > - /* If the next directory name to pop off is "..", break here */ > - if (!strcmp(sep ? &sep[1] : buf, "..")) { > - /* Readd the slash we just removed */ > - av_strlcat(buf, "/", size); > - break; > - } > - /* Cut off the directory name */ > - if (sep) > - sep[1] = '\0'; > - else > - buf[0] = '\0'; > - rel += 3; > - } > av_strlcat(buf, rel, size); > trim_double_dot_url(tmp_path, buf, size); > memset(buf, 0, size); > -- > 2.17.1 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe". I have resubmit new patch v3 to the old thread, you can try that. Thanks Steven
diff --git a/libavformat/url.c b/libavformat/url.c index 20463a6674..343cbca9b9 100644 --- a/libavformat/url.c +++ b/libavformat/url.c @@ -83,8 +83,10 @@ static void trim_double_dot_url(char *buf, const char *rel, int size) const char *p = rel; const char *root = rel; char tmp_path[MAX_URL_SIZE] = {0, }; - char *sep; - char *node; + int tmp_len = 0; + const char *sep; + const char *next; + int last_is_dir; /* Get the path root of the url which start by "://" */ if (p && (sep = strstr(p, "://"))) { @@ -93,29 +95,45 @@ static void trim_double_dot_url(char *buf, const char *rel, int size) if (!root) return; } + if (*root == '/') + ++root; + + /* Split the path by "/" and remove ".." and its corresponding directory. */ + last_is_dir = 1; + for (p = root; *p; p = next) { + next = strchr(p, '/'); + if (!next) { + next = p + strlen(p); + last_is_dir = 0; + } - /* set new current position if the root node is changed */ - p = root; - while (p && (node = strstr(p, ".."))) { - av_strlcat(tmp_path, p, node - p + strlen(tmp_path)); - p = node + 3; - sep = strrchr(tmp_path, '/'); - if (sep) - sep[0] = '\0'; - else - tmp_path[0] = '\0'; - } + if (next - p == 2 && !strncmp(p, "..", 2)) { + /* remove the last directory from tmp_path */ + while (tmp_len > 0 && tmp_path[--tmp_len] != '/') + ; + tmp_path[tmp_len] = '\0'; + last_is_dir = 1; + } else if (next > p) { + /* copy the current path component to tmp_path (including '/') */ + if (tmp_len) { + av_strlcpy(tmp_path + tmp_len, "/", sizeof(tmp_path) - tmp_len); + ++tmp_len; + } + av_strlcpy(tmp_path + tmp_len, p, FFMIN(sizeof(tmp_path) - tmp_len, + next - p + 1)); + tmp_len += next - p; + tmp_path[tmp_len] = '\0'; + } - if (!av_stristart(p, "/", NULL) && root != rel) - av_strlcat(tmp_path, "/", size); + /* skip "/" */ + while (*next == '/') + ++next; + } + if (last_is_dir && tmp_len) + av_strlcpy(tmp_path + tmp_len, "/", sizeof(tmp_path) - tmp_len); - av_strlcat(tmp_path, p, size); /* start set buf after temp path process. */ av_strlcpy(buf, rel, root - rel + 1); - - if (!av_stristart(tmp_path, "/", NULL) && root != rel) - av_strlcat(buf, "/", size); - av_strlcat(buf, tmp_path, size); } @@ -175,14 +193,11 @@ void ff_make_absolute_url(char *buf, int size, const char *base, root = p = buf; /* Get the path root of the url which start by "://" */ - if (p && strstr(p, "://")) { - sep = strstr(p, "://"); - if (sep) { - sep += 3; - root = strchr(sep, '/'); - if (!root) - return; - } + if (p && (sep = strstr(p, "://"))) { + sep += 3; + root = strchr(sep, '/'); + if (!root) + return; } /* Remove the file name from the base url */ @@ -194,26 +209,7 @@ void ff_make_absolute_url(char *buf, int size, const char *base, sep[1] = '\0'; else buf[0] = '\0'; - while (av_strstart(rel, "..", NULL) && sep) { - /* Remove the path delimiter at the end */ - if (sep > root) { - sep[0] = '\0'; - sep = strrchr(buf, '/'); - } - /* If the next directory name to pop off is "..", break here */ - if (!strcmp(sep ? &sep[1] : buf, "..")) { - /* Readd the slash we just removed */ - av_strlcat(buf, "/", size); - break; - } - /* Cut off the directory name */ - if (sep) - sep[1] = '\0'; - else - buf[0] = '\0'; - rel += 3; - } av_strlcat(buf, rel, size); trim_double_dot_url(tmp_path, buf, size); memset(buf, 0, size);
Fixes: 8814 The logic for removing ".." path components and their corresponding upper directories was reworked. Now, the function trim_double_dot_url splits the path by "/" into components, and processes the components one ny one: - if the component is "..", the last path component in tmp_path is removed - if the component is not empty, it is added to tmp_path The duplicate logic was removed from ff_make_absolute_url. Signed-off-by: Josef Zlomek <josef@pex.com> --- libavformat/url.c | 90 ++++++++++++++++++++++------------------------- 1 file changed, 43 insertions(+), 47 deletions(-)