Fixed alignment problems in nss client/server

I fixed a handful of alignment problems in sss_client and nss responder.
Enumerating group and passwd with getgrent and getpwent now works correctly
on ARM.

Signed-off-by: George McCollister <georgem@novatech-llc.com>

3 files changed, 32 insertions, 7 deletions

diff --git a/src/sss_client/group.c b/src/sss_client/group.c
index 675b8b71e..e1b36e2a4 100644
--- a/src/sss_client/group.c
+++ b/src/sss_client/group.c
@@ -78,17 +78,19 @@ struct sss_nss_gr_rep {
 static int sss_nss_getgr_readrep(struct sss_nss_gr_rep *pr,
                                  uint8_t *buf, size_t *len)
 {
-    size_t i, l, slen, ptmem;
+    size_t i, l, slen, ptmem, pad;
     ssize_t dlen;
     char *sbuf;
     uint32_t mem_num;
+    uint32_t c;
 
     if (*len < 11) { /* not enough space for data, bad packet */
         return EBADMSG;
     }
 
-    pr->result->gr_gid = ((uint32_t *)buf)[0];
-    mem_num = ((uint32_t *)buf)[1];
+    SAFEALIGN_COPY_UINT32(&c, buf, NULL);
+    pr->result->gr_gid = c;
+    SAFEALIGN_COPY_UINT32(&mem_num, buf+sizeof(uint32_t), NULL);
 
     sbuf = (char *)&buf[8];
     slen = *len - 8;
@@ -127,9 +129,15 @@ static int sss_nss_getgr_readrep(struct sss_nss_gr_rep *pr,
     i++;
     dlen--;
 
+    /* Make sure pr->buffer[i+pad] is 32 bit aligned */
+    pad = 0;
+    while((i + pad) % 4) {
+        pad++;
+    }
+
     /* now members */
-    pr->result->gr_mem = (char **)&(pr->buffer[i]);
-    ptmem = sizeof(char *) * (mem_num + 1);
+    pr->result->gr_mem = (char **)&(pr->buffer[i+pad]);
+    ptmem = (sizeof(char *) * (mem_num + 1)) + pad;
     if (ptmem > dlen) {
         return ERANGE; /* not ENOMEM, ERANGE is what glibc looks for */
     }
diff --git a/src/sss_client/passwd.c b/src/sss_client/passwd.c
index 0d70b6843..aa5c76023 100644
--- a/src/sss_client/passwd.c
+++ b/src/sss_client/passwd.c
@@ -74,13 +74,16 @@ static int sss_nss_getpw_readrep(struct sss_nss_pw_rep *pr,
 {
     size_t i, slen, dlen;
     char *sbuf;
+    uint32_t c;
 
     if (*len < 13) { /* not enough space for data, bad packet */
         return EBADMSG;
     }
 
-    pr->result->pw_uid = ((uint32_t *)buf)[0];
-    pr->result->pw_gid = ((uint32_t *)buf)[1];
+    SAFEALIGN_COPY_UINT32(&c, buf, NULL);
+    pr->result->pw_uid = c;
+    SAFEALIGN_COPY_UINT32(&c, buf+sizeof(uint32_t), NULL);
+    pr->result->pw_gid = c;
 
     sbuf = (char *)&buf[8];
     slen = *len - 8;
diff --git a/src/sss_client/sss_cli.h b/src/sss_client/sss_cli.h
index 1953db2f4..2edd158db 100644
--- a/src/sss_client/sss_cli.h
+++ b/src/sss_client/sss_cli.h
@@ -408,6 +408,20 @@ int sss_pam_make_request(enum sss_cli_command cmd,
                                      uint8_t **repbuf, size_t *replen,
                                      int *errnop);
 
+#ifndef SAFEALIGN_COPY_UINT32
+static inline void
+safealign_memcpy(void *dest, const void *src, size_t n, size_t *counter)
+{
+    memcpy(dest, src, n);
+    if (counter) {
+        *counter += n;
+    }
+}
+
+#define SAFEALIGN_COPY_UINT32(dest, src, pctr) \
+    safealign_memcpy(dest, src, sizeof(uint32_t), pctr)
+#endif
+
 #endif /* _SSSCLI_H */
 
 #if 0