From 2911006dcd808278e26b990dd26b268183fc27b4 Mon Sep 17 00:00:00 2001 From: Ingo Schwarze Date: Sun, 19 Jul 2015 06:05:16 +0000 Subject: Do not fork and exec gunzip(1), just link with libz instead. As discussed with deraadt@, that's cleaner and will help tame(2). Something like this was also suggested earlier by bapt at FreeBSD. Minus 50 lines of code, deleting one interface function (mparse_wait), no functional change intended. --- read.c | 114 ++++++++++++++++++----------------------------------------------- 1 file changed, 32 insertions(+), 82 deletions(-) (limited to 'read.c') diff --git a/read.c b/read.c index 40fb15a4..11b24ac1 100644 --- a/read.c +++ b/read.c @@ -23,19 +23,18 @@ #include #include #endif -#include #include #include #include #include -#include #include #include #include #include #include #include +#include #include "mandoc_aux.h" #include "mandoc.h" @@ -60,10 +59,10 @@ struct mparse { enum mandoclevel file_status; /* status of current parse */ enum mandoclevel wlevel; /* ignore messages below this */ int options; /* parser options */ + int gzip; /* current input file is gzipped */ int filenc; /* encoding of the current file */ int reparse_count; /* finite interp. stack */ int line; /* line number in the file */ - pid_t child; /* the gunzip(1) process */ }; static void choose_parser(struct mparse *); @@ -327,7 +326,6 @@ mparse_buf_r(struct mparse *curp, struct buf blk, size_t i, int start) int of; int lnn; /* line number in the real file */ int fd; - pid_t save_child; unsigned char c; memset(&ln, 0, sizeof(ln)); @@ -539,7 +537,6 @@ rerun: if (curp->secondary) curp->secondary->sz -= pos + 1; save_file = curp->file; - save_child = curp->child; if (mparse_open(curp, &fd, ln.buf + of) == MANDOCLEVEL_OK) { mparse_readfd(curp, fd, ln.buf + of); @@ -557,7 +554,6 @@ rerun: of = 0; mparse_buf_r(curp, ln, of, 0); } - curp->child = save_child; pos = 0; continue; default: @@ -611,6 +607,7 @@ static int read_whole_file(struct mparse *curp, const char *file, int fd, struct buf *fb, int *with_mmap) { + gzFile gz; size_t off; ssize_t ssz; @@ -628,7 +625,7 @@ read_whole_file(struct mparse *curp, const char *file, int fd, * concerned that this is going to tank any machines. */ - if (S_ISREG(st.st_mode)) { + if (curp->gzip == 0 && S_ISREG(st.st_mode)) { if (st.st_size > 0x7fffffff) { mandoc_msg(MANDOCERR_TOOLARGE, curp, 0, 0, NULL); return(0); @@ -641,6 +638,14 @@ read_whole_file(struct mparse *curp, const char *file, int fd, } #endif + if (curp->gzip) { + if ((gz = gzdopen(fd, "rb")) == NULL) { + perror(file); + exit((int)MANDOCLEVEL_SYSERR); + } + } else + gz = NULL; + /* * If this isn't a regular file (like, say, stdin), then we must * go the old way and just read things in bit by bit. @@ -659,7 +664,9 @@ read_whole_file(struct mparse *curp, const char *file, int fd, } resize_buf(fb, 65536); } - ssz = read(fd, fb->buf + (int)off, fb->sz - off); + ssz = curp->gzip ? + gzread(gz, fb->buf + (int)off, fb->sz - off) : + read(fd, fb->buf + (int)off, fb->sz - off); if (ssz == 0) { fb->sz = off; return(1); @@ -773,99 +780,42 @@ mparse_readfd(struct mparse *curp, int fd, const char *file) if (fd != STDIN_FILENO && close(fd) == -1) perror(file); - mparse_wait(curp); return(curp->file_status); } enum mandoclevel mparse_open(struct mparse *curp, int *fd, const char *file) { - int pfd[2]; - int save_errno; char *cp; curp->file = file; + cp = strrchr(file, '.'); + curp->gzip = (cp != NULL && ! strcmp(cp + 1, "gz")); - /* Unless zipped, try to just open the file. */ + /* First try to use the filename as it is. */ - if ((cp = strrchr(file, '.')) == NULL || - strcmp(cp + 1, "gz")) { - curp->child = 0; - if ((*fd = open(file, O_RDONLY)) != -1) - return(MANDOCLEVEL_OK); + if ((*fd = open(file, O_RDONLY)) != -1) + return(MANDOCLEVEL_OK); - /* Open failed; try to append ".gz". */ + /* + * If that doesn't work and the filename doesn't + * already end in .gz, try appending .gz. + */ + if ( ! curp->gzip) { mandoc_asprintf(&cp, "%s.gz", file); - file = cp; - } else - cp = NULL; - - /* Before forking, make sure the file can be read. */ - - save_errno = errno; - if (access(file, R_OK) == -1) { - if (cp != NULL) - errno = save_errno; + *fd = open(file, O_RDONLY); free(cp); - *fd = -1; - curp->child = 0; - mandoc_msg(MANDOCERR_FILE, curp, 0, 0, strerror(errno)); - return(MANDOCLEVEL_ERROR); - } - - /* Run gunzip(1). */ - - if (pipe(pfd) == -1) { - perror("pipe"); - exit((int)MANDOCLEVEL_SYSERR); - } - - switch (curp->child = fork()) { - case -1: - perror("fork"); - exit((int)MANDOCLEVEL_SYSERR); - case 0: - close(pfd[0]); - if (dup2(pfd[1], STDOUT_FILENO) == -1) { - perror("dup"); - exit((int)MANDOCLEVEL_SYSERR); + if (*fd != -1) { + curp->gzip = 1; + return(MANDOCLEVEL_OK); } - signal(SIGPIPE, SIG_DFL); - execlp("gunzip", "gunzip", "-c", file, NULL); - perror("exec"); - exit((int)MANDOCLEVEL_SYSERR); - default: - close(pfd[1]); - *fd = pfd[0]; - return(MANDOCLEVEL_OK); } -} -enum mandoclevel -mparse_wait(struct mparse *curp) -{ - int status; - - if (curp->child == 0) - return(MANDOCLEVEL_OK); + /* Neither worked, give up. */ - if (waitpid(curp->child, &status, 0) == -1) { - perror("wait"); - exit((int)MANDOCLEVEL_SYSERR); - } - curp->child = 0; - if (WIFSIGNALED(status)) { - mandoc_vmsg(MANDOCERR_FILE, curp, 0, 0, - "gunzip died from signal %d", WTERMSIG(status)); - return(MANDOCLEVEL_ERROR); - } - if (WEXITSTATUS(status)) { - mandoc_vmsg(MANDOCERR_FILE, curp, 0, 0, - "gunzip failed with code %d", WEXITSTATUS(status)); - return(MANDOCLEVEL_ERROR); - } - return(MANDOCLEVEL_OK); + mandoc_msg(MANDOCERR_FILE, curp, 0, 0, strerror(errno)); + return(MANDOCLEVEL_ERROR); } struct mparse * -- cgit