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Unverified Commit 6d8c2779 by Christian Brauner
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lxc-user-nic: bugfixes

Since find_line() was changed before count_entries() started counting lines wrong. It would report maximum reached before you actually reached your alloted maximum. Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
parent d75c14e2
Showing with 114 additions and 85 deletions
src/lxc/lxc_user_nic.c
......@@ -357,41 +357,94 @@ static char *get_eow(char *s, char *e)
return s;
}
static char *find_line(char *p, char *e, char *u, char *t, char *l)
static char *find_line(char *buf_start, char *buf_end, char *name,
char *net_type, char *net_link, char *net_dev,
bool *owner, bool *found, bool *keep)
{
char *p1, *p2, *ret;
char *end_of_line, *end_of_word, *line;
while ((p < e) && (p1 = get_eol(p, e)) < e) {
ret = p;
if (*p == '#')
while (buf_start < buf_end) {
size_t len;
char netdev_name[IFNAMSIZ];
*found = false;
*keep = true;
*owner = false;
end_of_line = get_eol(buf_start, buf_end);
if (end_of_line >= buf_end)
return NULL;
line = buf_start;
if (*buf_start == '#')
goto next;
while ((p < e) && isblank(*p))
p++;
while ((buf_start < buf_end) && isblank(*buf_start))
buf_start++;
/* Check whether the line contains the caller's name. */
end_of_word = get_eow(buf_start, buf_end);
/* corrupt db */
if (!end_of_word)
return NULL;
if (strncmp(buf_start, name, strlen(name)))
*found = false;
*owner = true;
buf_start = end_of_word + 1;
while ((buf_start < buf_end) && isblank(*buf_start))
buf_start++;
/* Check whether line is of the right network type. */
end_of_word = get_eow(buf_start, buf_end);
/* corrupt db */
if (!end_of_word)
return NULL;
if (strncmp(buf_start, net_type, strlen(net_type)))
*found = false;
buf_start = end_of_word + 1;
while ((buf_start < buf_end) && isblank(*buf_start))
buf_start++;
/* Check whether line is contains the right link. */
end_of_word = get_eow(buf_start, buf_end);
/* corrupt db */
if (!end_of_word)
return NULL;
p2 = get_eow(p, e);
if (!p2 || ((size_t)(p2 - p)) != strlen(u) || strncmp(p, u, strlen(u)))
return ret;
if (strncmp(buf_start, net_link, strlen(net_link)))
*found = false;
p = p2 + 1;
while ((p < e) && isblank(*p))
p++;
buf_start = end_of_word + 1;
while ((buf_start < buf_end) && isblank(*buf_start))
buf_start++;
p2 = get_eow(p, e);
if (!p2 || ((size_t)(p2 - p)) != strlen(t) || strncmp(p, t, strlen(t)))
return ret;
/* Check whether line contains the right network device. */
end_of_word = get_eow(buf_start, buf_end);
/* corrupt db */
if (!end_of_word)
return NULL;
len = end_of_word - buf_start;
/* corrupt db */
if (len >= IFNAMSIZ)
return NULL;
p = p2 + 1;
while ((p < e) && isblank(*p))
p++;
memcpy(netdev_name, buf_start, len);
netdev_name[len] = '\0';
*keep = lxc_nic_exists(netdev_name);
p2 = get_eow(p, e);
if (!p2 || ((size_t)(p2 - p)) != strlen(l) || strncmp(p, l, strlen(l)))
return ret;
if (net_dev && !strcmp(netdev_name, net_dev))
*found = true;
return line;
return ret;
next:
p = p1 + 1;
buf_start = end_of_line + 1;
}
return NULL;
......@@ -532,50 +585,30 @@ static char *get_new_nicname(char *br, int pid, char **cnic)
return nicname;
}
static bool get_nic_from_line(char *p, char **nic)
{
int ret;
char user[100], type[100], br[100];
ret = sscanf(p, "%99[^ \t\n] %99[^ \t\n] %99[^ \t\n] %99[^ \t\n]", user,
type, br, *nic);
if (ret != 4) {
*nic[0] = '\0';
return false;
}
return true;
}
struct entry_line {
char *start;
int len;
bool keep;
};
static bool cull_entries(int fd, char *me, char *t, char *br, char *nicname,
bool *found_nicname)
static bool cull_entries(int fd, char *name, char *net_type, char *net_link,
char *net_dev, bool *found_nicname)
{
int i, ret;
off_t len;
char *buf, *e, *nic, *p;
char *buf, *buf_end, *buf_start;
struct stat sb;
int n = 0;
bool found, keep;
struct entry_line *entry_lines = NULL;
nic = alloca(100);
if (!nic)
return false;
ret = fstat(fd, &sb);
if (ret < 0) {
usernic_error("Failed to fstat: %s\n", strerror(errno));
return false;
}
len = sb.st_size;
if (len == 0)
return true;
if (!sb.st_size)
return false;
buf = lxc_strmmap(NULL, sb.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (buf == MAP_FAILED) {
......@@ -584,55 +617,48 @@ static bool cull_entries(int fd, char *me, char *t, char *br, char *nicname,
return false;
}
p = buf;
e = buf + len;
while ((p = find_line(p, e, me, t, br))) {
buf_start = buf;
buf_end = buf + sb.st_size;
while ((buf_start = find_line(buf_start, buf_end, name, net_type,
net_link, net_dev, &(bool){true}, &found,
&keep))) {
struct entry_line *newe;
bool exists = false;
newe = realloc(entry_lines, sizeof(*entry_lines) * (n + 1));
if (!newe) {
free(entry_lines);
lxc_strmunmap(buf, sb.st_size);
return false;
}
if (found)
*found_nicname = true;
entry_lines = newe;
entry_lines[n].start = p;
entry_lines[n].len = get_eol(p, e) - entry_lines[n].start;
entry_lines[n].keep = true;
entry_lines[n].start = buf_start;
entry_lines[n].len = get_eol(buf_start, buf_end) - entry_lines[n].start;
entry_lines[n].keep = keep;
n++;
if (!get_nic_from_line(p, &nic))
continue;
if (nic[0] != '\0')
exists = lxc_nic_exists(nic);
if (!exists)
entry_lines[n - 1].keep = false;
if (exists && nicname)
if (!strcmp(nic, nicname))
*found_nicname = true;
p += entry_lines[n - 1].len + 1;
if (p >= e)
buf_start += entry_lines[n - 1].len + 1;
if (buf_start >= buf_end)
break;
}
p = buf;
buf_start = buf;
for (i = 0; i < n; i++) {
if (!entry_lines[i].keep)
continue;
memcpy(p, entry_lines[i].start, entry_lines[i].len);
p += entry_lines[i].len;
*p = '\n';
p++;
memcpy(buf_start, entry_lines[i].start, entry_lines[i].len);
buf_start += entry_lines[i].len;
*buf_start = '\n';
buf_start++;
}
free(entry_lines);
lxc_strmunmap(buf, sb.st_size);
ret = ftruncate(fd, p - buf);
ret = ftruncate(fd, buf_start - buf);
if (ret < 0)
usernic_error("Failed to set new file size: %s\n",
strerror(errno));
......@@ -640,16 +666,19 @@ static bool cull_entries(int fd, char *me, char *t, char *br, char *nicname,
return true;
}
static int count_entries(char *buf, off_t len, char *me, char *t, char *br)
static int count_entries(char *buf, off_t len, char *name, char *net_type, char *net_link)
{
char *e;
int count = 0;
e = &buf[len];
while ((buf = find_line(buf, e, me, t, br))) {
count++;
buf = get_eol(buf, e) + 1;
if (buf >= e)
bool owner = false;;
char *buf_end = &buf[len];
buf_end = &buf[len];
while ((buf = find_line(buf, buf_end, name, net_type, net_link, NULL,
&owner, &(bool){true}, &(bool){true}))) {
if (owner)
count++;
buf = get_eol(buf, buf_end) + 1;
if (buf >= buf_end)
break;
}
......
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