lib: Add mlibc

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/lib/mlibc/sysdeps/lyre/generic/mntent.cpp b/lib/mlibc/sysdeps/lyre/generic/mntent.cpp
new file mode 100644
index 0000000..d064af3
--- /dev/null
+++ b/lib/mlibc/sysdeps/lyre/generic/mntent.cpp
@@ -0,0 +1,97 @@
+#include <errno.h>
+#include <mntent.h>
+#include <stdio.h>
+#include <limits.h>
+#include <string.h>
+#include <bits/ensure.h>
+
+namespace {
+
+char *internal_buf;
+size_t internal_bufsize;
+
+}
+
+#define SENTINEL (char *)&internal_buf
+
+FILE *setmntent(const char *name, const char *mode) {
+	return fopen(name, mode);
+}
+
+struct mntent *getmntent(FILE *f) {
+	static struct mntent mnt;
+	return getmntent_r(f, &mnt, SENTINEL, 0);
+}
+
+int addmntent(FILE *f, const struct mntent *mnt) {
+	if(fseek(f, 0, SEEK_END)) {
+		return 1;
+	}
+	return fprintf(f, "%s\t%s\t%s\t%s\t%d\t%d\n",
+		mnt->mnt_fsname, mnt->mnt_dir, mnt->mnt_type, mnt->mnt_opts,
+		mnt->mnt_freq, mnt->mnt_passno) < 0;
+}
+
+int endmntent(FILE *f) {
+	if(f) {
+		fclose(f);
+	}
+	return 1;
+}
+
+char *hasmntopt(const struct mntent *mnt, const char *opt) {
+	return strstr(mnt->mnt_opts, opt);
+}
+
+/* Adapted from musl */
+struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int buflen) {
+	int n[8];
+	bool use_internal = (linebuf == SENTINEL);
+	int len;
+	size_t i;
+
+	mnt->mnt_freq = 0;
+	mnt->mnt_passno = 0;
+
+	do {
+		if(use_internal) {
+			getline(&internal_buf, &internal_bufsize, f);
+			linebuf = internal_buf;
+		} else {
+			fgets(linebuf, buflen, f);
+		}
+		if(feof(f) || ferror(f)) {
+			return 0;
+		}
+		if(!strchr(linebuf, '\n')) {
+			fscanf(f, "%*[^\n]%*[\n]");
+			errno = ERANGE;
+			return 0;
+		}
+
+		len = strlen(linebuf);
+		if(len > INT_MAX) {
+			continue;
+		}
+
+		for(i = 0; i < sizeof n / sizeof *n; i++) {
+			n[i] = len;
+		}
+
+		sscanf(linebuf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
+			n, n + 1, n + 2, n + 3, n + 4, n + 5, n + 6, n + 7,
+			&mnt->mnt_freq, &mnt->mnt_passno);
+	} while(linebuf[n[0]] == '#' || n[1] == len);
+
+	linebuf[n[1]] = 0;
+	linebuf[n[3]] = 0;
+	linebuf[n[5]] = 0;
+	linebuf[n[7]] = 0;
+
+	mnt->mnt_fsname = linebuf + n[0];
+	mnt->mnt_dir = linebuf + n[2];
+	mnt->mnt_type = linebuf + n[4];
+	mnt->mnt_opts = linebuf + n[6];
+
+	return mnt;
+}