10:04 a.m.
From: Richard Jones <rjones(a)trick.home.annexia.org>
This just tidies up the main() function in the daemon. There is
no longer a huge fixed-sized buffer used for the kernel command
line. Variables are moved closer to where they are used. Some
local variables turned out to be unused - these are removed. Finally
the part that reads the kernel command line is moved into a separate
function.
There is only minimal functional change here (it now prints out
the kernel command line).
---
daemon/guestfsd.c | 104 +++++++++++++++++++++++++++++++++++++---------------
1 files changed, 74 insertions(+), 30 deletions(-)
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index bfd8139..a38452c 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -41,10 +41,11 @@
#include "daemon.h"
static void usage (void);
+static char *read_cmdline (void);
/* Also in guestfs.c */
-#define GUESTFWD_PORT "6666"
#define GUESTFWD_ADDR "10.0.2.4"
+#define GUESTFWD_PORT "6666"
int verbose = 0;
@@ -73,17 +74,9 @@ main (int argc, char *argv[])
{ "help", 0, 0, '?' },
{ 0, 0, 0, 0 }
};
- int c, n, r;
+ int c;
int dont_fork = 0;
- FILE *fp;
- char buf[4096];
- char *p, *p2;
- int sock;
- struct addrinfo *res, *rr;
- struct addrinfo hints;
- XDR xdr;
- uint32_t len;
- struct sigaction sa;
+ char *cmdline;
#ifdef HAVE_REGISTER_PRINTF_SPECIFIER
/* http://udrepper.livejournal.com/20948.html */
@@ -122,22 +115,22 @@ main (int argc, char *argv[])
exit (1);
}
- /* Set the verbose flag. */
- fp = fopen ("/proc/cmdline", "r");
- if (fp == NULL) {
- perror ("/proc/cmdline");
- goto next;
- }
- n = fread (buf, 1, sizeof buf - 1, fp);
- fclose (fp);
- buf[n] = '\0';
+ cmdline = read_cmdline ();
- verbose = strstr (buf, "guestfs_verbose=1") != NULL;
+ /* Set the verbose flag. */
+ verbose = cmdline && strstr (cmdline, "guestfs_verbose=1") != NULL;
if (verbose)
printf ("verbose daemon enabled\n");
- next:
+ if (verbose) {
+ if (cmdline)
+ printf ("linux commmand line: %s\n", cmdline);
+ else
+ printf ("could not read linux command line\n");
+ }
+
/* Make sure SIGPIPE doesn't kill us. */
+ struct sigaction sa;
memset (&sa, 0, sizeof sa);
sa.sa_handler = SIG_IGN;
sa.sa_flags = 0;
@@ -156,6 +149,9 @@ main (int argc, char *argv[])
umask (022);
/* Resolve the hostname. */
+ struct addrinfo *res, *rr;
+ struct addrinfo hints;
+ int r;
memset (&hints, 0, sizeof hints);
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_ADDRCONFIG;
@@ -167,7 +163,7 @@ main (int argc, char *argv[])
}
/* Connect to the given TCP socket. */
- sock = -1;
+ int sock = -1;
for (rr = res; rr != NULL; rr = rr->ai_next) {
sock = socket (rr->ai_family, rr->ai_socktype, rr->ai_protocol);
if (sock != -1) {
@@ -190,14 +186,13 @@ main (int argc, char *argv[])
/* Send the magic length message which indicates that
* userspace is up inside the guest.
*/
- len = GUESTFS_LAUNCH_FLAG;
- xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
- if (!xdr_uint32_t (&xdr, &len)) {
- fprintf (stderr, "xdr_uint32_t failed\n");
- exit (1);
- }
+ char lenbuf[4];
+ XDR xdr;
+ uint32_t len = GUESTFS_LAUNCH_FLAG;
+ xdrmem_create (&xdr, lenbuf, sizeof lenbuf, XDR_ENCODE);
+ xdr_uint32_t (&xdr, &len);
- if (xwrite (sock, buf, xdr_getpos (&xdr)) == -1)
+ if (xwrite (sock, lenbuf, 4) == -1)
exit (1);
xdr_destroy (&xdr);
@@ -216,6 +211,55 @@ main (int argc, char *argv[])
exit (0);
}
+/* Read /proc/cmdline. */
+static char *
+read_cmdline (void)
+{
+ int fd = open ("/proc/cmdline", O_RDONLY);
+ if (fd == -1) {
+ perror ("/proc/cmdline");
+ return NULL;
+ }
+
+ size_t len = 0;
+ ssize_t n;
+ char buf[256];
+ char *r = NULL;
+
+ for (;;) {
+ n = read (fd, buf, sizeof buf);
+ if (n == -1) {
+ perror ("read");
+ free (r);
+ close (fd);
+ return NULL;
+ }
+ if (n == 0)
+ break;
+ char *newr = realloc (r, len + n + 1); /* + 1 is for terminating NUL */
+ if (newr == NULL) {
+ perror ("realloc");
+ free (r);
+ close (fd);
+ return NULL;
+ }
+ r = newr;
+ memcpy (&r[len], buf, n);
+ len += n;
+ }
+
+ if (r)
+ r[len] = '\0';
+
+ if (close (fd) == -1) {
+ perror ("close");
+ free (r);
+ return NULL;
+ }
+
+ return r;
+}
+
/* Turn "/path" into "/sysroot/path".
*
* Caller must check for NULL and call reply_with_perror ("malloc")
--
1.6.2.5