diff options
Diffstat (limited to 'libbb')
| -rw-r--r-- | libbb/gz_open.c | 75 | ||||
| -rw-r--r-- | libbb/libbb.h | 2 | ||||
| -rw-r--r-- | libbb/unarchive.c | 12 |
3 files changed, 83 insertions, 6 deletions
diff --git a/libbb/gz_open.c b/libbb/gz_open.c index dbaf3bb..ba4d6a5 100644 --- a/libbb/gz_open.c +++ b/libbb/gz_open.c @@ -56,3 +56,78 @@ extern FILE *gz_open(FILE *compressed_file, int *pid) } return(fdopen(unzip_pipe[0], "r")); } + +/* gz_open implementation using gunzip and a vfork/exec -- dodges OOM killer */ +extern FILE *gzvopen(FILE *compressed_file, int *pid) +{ + int unzip_pipe[2]; + off_t floc; + int cfile; + + /* create a new file descriptor for the input stream + * (it *must* be associated with a file) + * and seek to the same position in that fd as the stream. + */ + cfile = dup(fileno(compressed_file)); + floc = ftello(compressed_file); + lseek(cfile, floc, SEEK_SET); + + /* create the pipe */ + if (pipe(unzip_pipe)!=0) { + error_msg("gzvopen(): pipe error"); + return(NULL); + } + + *pid = vfork(); + + if (*pid < 0) { + error_msg("gzvopen(): fork failed"); + return(NULL); + } + + if (*pid==0) { + /* child process - reads STDIN, writes to pipe */ + + /* close unused read end of pipe */ + close(unzip_pipe[0]); + + /* connect child's stdout to the pipe write end */ + dup2(unzip_pipe[1], 1); + + /* connect child's stdin to the fd passed in to us */ + dup2(cfile, 0); + + /* execute the gunzip utility */ + execlp("gunzip","gunzip",NULL); + + /* if we get here, we had a failure - since we are + * using vfork(), we cannot call exit(), must call _exit(). + */ + _exit(-1); + } + + /* Parent process is executing here */ + + /* we have no more need of the duplicate fd */ + close(cfile); + + /* close the write end of the pipe */ + close(unzip_pipe[1]); + + /* return the read end of the pipe as a FILE */ + return(fdopen(unzip_pipe[0], "r")); +} + +extern void gzvclose(int gunzip_pid) +{ + if (kill(gunzip_pid, SIGTERM) == -1) { + perror("gzvclose()"); + fprintf(stderr,"%s: unable to kill gunzip pid.\n", + __FUNCTION__); + } + + if (waitpid(gunzip_pid, NULL, 0) == -1) { + fprintf(stderr,"%s: unable to wait on gunzip pid.\n", + __FUNCTION__); + } +} diff --git a/libbb/libbb.h b/libbb/libbb.h index 860dacd..238e5a7 100644 --- a/libbb/libbb.h +++ b/libbb/libbb.h @@ -270,6 +270,8 @@ char *fgets_str(FILE *file, const char *terminating_string); extern int unzip(FILE *l_in_file, FILE *l_out_file); extern void gz_close(int gunzip_pid); extern FILE *gz_open(FILE *compressed_file, int *pid); +extern void gzvclose(int gunzip_pid); +extern FILE *gzvopen(FILE *compressed_file, int *pid); extern struct hostent *xgethostbyname(const char *name); extern int create_icmp_socket(void); diff --git a/libbb/unarchive.c b/libbb/unarchive.c index bb70ccb..3251c71 100644 --- a/libbb/unarchive.c +++ b/libbb/unarchive.c @@ -749,7 +749,7 @@ char *deb_extract(const char *package_filename, FILE *out_stream, while ((ar_header = get_header_ar(deb_stream)) != NULL) { if (strcmp(ared_file, ar_header->name) == 0) { /* open a stream of decompressed data */ - uncompressed_stream = gz_open(deb_stream, &gunzip_pid); + uncompressed_stream = gzvopen(deb_stream, &gunzip_pid); archive_offset = 0; output_buffer = unarchive(uncompressed_stream, out_stream, get_header_tar, free_header_tar, extract_function, prefix, file_list); } @@ -757,7 +757,7 @@ char *deb_extract(const char *package_filename, FILE *out_stream, free (ar_header->name); free (ar_header); } - gz_close(gunzip_pid); + gzvclose(gunzip_pid); fclose(deb_stream); fclose(uncompressed_stream); free(ared_file); @@ -769,7 +769,7 @@ char *deb_extract(const char *package_filename, FILE *out_stream, file_header_t *tar_header; archive_offset = 0; fseek(deb_stream, 0, SEEK_SET); - unzipped_opkg_stream = gz_open(deb_stream, &unzipped_opkg_pid); + unzipped_opkg_stream = gzvopen(deb_stream, &unzipped_opkg_pid); /*fprintf(stderr, __FUNCTION__ ": processing opkg %s -- ared_file=%s\n", package_filename, ared_file);*/ /* walk through outer tar file to find ared_file */ @@ -779,7 +779,7 @@ char *deb_extract(const char *package_filename, FILE *out_stream, name_offset = 2; if (strcmp(ared_file, tar_header->name+name_offset) == 0) { /* open a stream of decompressed data */ - uncompressed_stream = gz_open(unzipped_opkg_stream, &gunzip_pid); + uncompressed_stream = gzvopen(unzipped_opkg_stream, &gunzip_pid); archive_offset = 0; /*fprintf(stderr, __FUNCTION__ ":%d: here -- found file\n", __LINE__);*/ output_buffer = unarchive(uncompressed_stream, @@ -791,14 +791,14 @@ char *deb_extract(const char *package_filename, FILE *out_stream, file_list); /*fprintf(stderr, __FUNCTION__ ":%d: unarchive complete\n", __LINE__);*/ free_header_tar(tar_header); - gz_close(gunzip_pid); + gzvclose(gunzip_pid); fclose(uncompressed_stream); break; } seek_sub_file(unzipped_opkg_stream, tar_header->size); free_header_tar(tar_header); } - gz_close(unzipped_opkg_pid); + gzvclose(unzipped_opkg_pid); fclose(unzipped_opkg_stream); fclose(deb_stream); free(ared_file); |