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Commit 65fcb758 by Christian Brauner Committed by Stéphane Graber
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lxc-ls: use fewer syscalls when doing ipc

Signed-off-by: 's avatarChristian Brauner <christian.brauner@mailbox.org>
parent b1b14a4e
Showing with 73 additions and 105 deletions
src/lxc/lxc_ls.c
......@@ -103,6 +103,8 @@ static char *ls_get_config_item(struct lxc_container *c, const char *item,
bool running);
static char *ls_get_groups(struct lxc_container *c, bool running);
static char *ls_get_ips(struct lxc_container *c, const char *inet);
static int ls_recv_str(int fd, char **buf);
static int ls_send_str(int fd, const char *buf);
struct wrapargs {
const struct lxc_arguments *args;
char **grps_must;
......@@ -146,14 +148,9 @@ static void ls_print_table(struct ls *l, struct lengths *lht,
/*
* id can only be 79 + \0 chars long.
*/
static int ls_read_and_grow_buf(const int rpipefd, char **save_buf,
const char *id, ssize_t nbytes_id,
char **read_buf, ssize_t *read_buf_len);
static int ls_remove_lock(const char *path, const char *name,
char **lockpath, size_t *len_lockpath, bool recalc);
static int ls_serialize(int wpipefd, struct ls *n);
static int ls_write(const int wpipefd, const char *id, ssize_t nbytes_id,
const char *s);
static int my_parser(struct lxc_arguments *args, int c, char *arg);
static const struct option my_longopts[] = {
......@@ -483,7 +480,7 @@ static int ls_get(struct ls **m, size_t *size, const struct lxc_arguments *args,
if (args->ls_nesting && running) {
struct wrapargs wargs = (struct wrapargs){.args = NULL};
/* Open a socket so that the child can communicate with us. */
check = socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, wargs.pipefd);
check = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wargs.pipefd);
if (check == -1)
goto put_and_next;
......@@ -1004,67 +1001,86 @@ static int ls_remove_lock(const char *path, const char *name,
return 0;
}
static int ls_send_str(int fd, const char *buf)
{
size_t slen = 0;
if (buf)
slen = strlen(buf);
if (lxc_write_nointr(fd, &slen, sizeof(slen)) != sizeof(slen))
return -1;
if (slen > 0) {
if (lxc_write_nointr(fd, buf, slen) != (ssize_t)slen)
return -1;
}
return 0;
}
static int ls_serialize(int wpipefd, struct ls *n)
{
ssize_t nbytes = sizeof(n->ram);
if (lxc_write_nointr(wpipefd, &n->ram, nbytes) != nbytes)
if (lxc_write_nointr(wpipefd, &n->ram, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->swap);
if (lxc_write_nointr(wpipefd, &n->swap, nbytes) != nbytes)
if (lxc_write_nointr(wpipefd, &n->swap, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->init);
if (lxc_write_nointr(wpipefd, &n->init, nbytes) != nbytes)
if (lxc_write_nointr(wpipefd, &n->init, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->autostart);
if (lxc_write_nointr(wpipefd, &n->autostart, nbytes) != nbytes)
if (lxc_write_nointr(wpipefd, &n->autostart, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->running);
if (lxc_write_nointr(wpipefd, &n->running, nbytes) != nbytes)
if (lxc_write_nointr(wpipefd, &n->running, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->nestlvl);
if (lxc_write_nointr(wpipefd, &n->nestlvl, nbytes) != nbytes)
if (lxc_write_nointr(wpipefd, &n->nestlvl, (size_t)nbytes) != nbytes)
return -1;
if (ls_write(wpipefd, "NAME:", 5 + 1, n->name) == -1)
/* NAME */
if (ls_send_str(wpipefd, n->name) < 0)
return -1;
if (ls_write(wpipefd, "STATE:", 6 + 1, n->state) == -1)
/* STATE */
if (ls_send_str(wpipefd, n->state) < 0)
return -1;
if (ls_write(wpipefd, "GROUPS:", 7 + 1, n->groups) == -1)
/* GROUPS */
if (ls_send_str(wpipefd, n->groups) < 0)
return -1;
if (ls_write(wpipefd, "INTERFACE:", 10 + 1, n->interface) == -1)
/* INTERFACE */
if (ls_send_str(wpipefd, n->interface) < 0)
return -1;
if (ls_write(wpipefd, "IPV4:", 5 + 1, n->ipv4) == -1)
/* IPV4 */
if (ls_send_str(wpipefd, n->ipv4) < 0)
return -1;
if (ls_write(wpipefd, "IPV6:", 5 + 1, n->ipv6) == -1)
/* IPV6 */
if (ls_send_str(wpipefd, n->ipv6) < 0)
return -1;
return 0;
}
static int ls_write(const int wpipefd, const char *id, ssize_t nbytes_id,
const char *s)
static int ls_recv_str(int fd, char **buf)
{
if (lxc_write_nointr(wpipefd, id, nbytes_id) != nbytes_id)
size_t slen = 0;
if (lxc_read_nointr(fd, &slen, sizeof(slen)) != sizeof(slen))
return -1;
if (s) {
nbytes_id = strlen(s) + 1;
if (lxc_write_nointr(wpipefd, s, nbytes_id) != nbytes_id)
if (slen > 0) {
*buf = malloc(sizeof(char) * (slen + 1));
if (!*buf)
return -1;
} else {
if (lxc_write_nointr(wpipefd, "\0", 1) != 1)
if (lxc_read_nointr(fd, *buf, slen) != (ssize_t)slen)
return -1;
(*buf)[slen] = '\0';
}
return 0;
}
......@@ -1073,111 +1089,63 @@ static int ls_deserialize(int rpipefd, struct ls **m, size_t *len)
struct ls *n;
size_t sublen = 0;
ssize_t nbytes = 0;
int ret = -1;
/* get length */
nbytes = sizeof(sublen);
if (lxc_read_nointr(rpipefd, &sublen, nbytes) != nbytes)
return -1;
char *serialized = NULL;
serialized = malloc(LINELEN * sizeof(char));
if (!serialized)
if (lxc_read_nointr(rpipefd, &sublen, (size_t)nbytes) != nbytes)
return -1;
while (sublen-- > 0) {
n = ls_new(m, len);
if (!n)
goto out;
return -1;
nbytes = sizeof(n->ram);
if (lxc_read_nointr(rpipefd, &n->ram, nbytes) != nbytes)
goto out;
if (lxc_read_nointr(rpipefd, &n->ram, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->swap);
if (lxc_read_nointr(rpipefd, &n->swap, nbytes) != nbytes)
goto out;
if (lxc_read_nointr(rpipefd, &n->swap, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->init);
if (lxc_read_nointr(rpipefd, &n->init, nbytes) != nbytes)
goto out;
if (lxc_read_nointr(rpipefd, &n->init, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->autostart);
if (lxc_read_nointr(rpipefd, &n->autostart, nbytes) != nbytes)
goto out;
if (lxc_read_nointr(rpipefd, &n->autostart, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->running);
if (lxc_read_nointr(rpipefd, &n->running, nbytes) != nbytes)
goto out;
if (lxc_read_nointr(rpipefd, &n->running, (size_t)nbytes) != nbytes)
return -1;
nbytes = sizeof(n->nestlvl);
if (lxc_read_nointr(rpipefd, &n->nestlvl, nbytes) != nbytes)
goto out;
ssize_t buf_size = LINELEN;
if (ls_read_and_grow_buf(rpipefd, &n->name, "NAME:", 5 + 1, &serialized, &buf_size) == -1)
goto out;
if (ls_read_and_grow_buf(rpipefd, &n->state, "STATE:", 6 + 1, &serialized, &buf_size) == -1)
goto out;
if (ls_read_and_grow_buf(rpipefd, &n->groups, "GROUPS:", 7 + 1, &serialized, &buf_size) == -1)
goto out;
if (ls_read_and_grow_buf(rpipefd, &n->interface, "INTERFACE:", 10 + 1, &serialized, &buf_size) == -1)
goto out;
if (ls_read_and_grow_buf(rpipefd, &n->ipv4, "IPV4:", 5 + 1, &serialized, &buf_size) == -1)
goto out;
if (ls_read_and_grow_buf(rpipefd, &n->ipv6, "IPV6:", 5 + 1, &serialized, &buf_size) == -1)
goto out;
}
ret = 0;
out:
free(serialized);
if (lxc_read_nointr(rpipefd, &n->nestlvl, (size_t)nbytes) != nbytes)
return -1;
return ret;
}
/* NAME */
if (ls_recv_str(rpipefd, &n->name) < 0)
return -1;
static int ls_read_and_grow_buf(const int rpipefd, char **save_buf,
const char *id, ssize_t nbytes_id,
char **read_buf, ssize_t *read_buf_len)
{
char *inc, *tmp;
char buf[80]; /* id can only be 79 + \0 long */
/* STATE */
if (ls_recv_str(rpipefd, &n->state) < 0)
return -1;
if (lxc_read_nointr(rpipefd, buf, nbytes_id) != nbytes_id)
return -1;
/* GROUPS */
if (ls_recv_str(rpipefd, &n->groups) < 0)
return -1;
if (strcmp(id, buf) != 0)
return -1;
/* INTERFACE */
if (ls_recv_str(rpipefd, &n->interface) < 0)
return -1;
inc = *read_buf;
nbytes_id = 0;
do {
/* if the next read would overflow our buffer realloc */
if (nbytes_id + 1 >= *read_buf_len) {
*read_buf_len += LINELEN;
tmp = realloc(*read_buf, *read_buf_len);
if (!tmp)
return -1;
*read_buf = tmp;
/* Put inc back to where it was before the realloc so we
* can keep on reading in the string. */
inc = *read_buf + nbytes_id;
}
/* only read one byte at a time */
if (lxc_read_nointr(rpipefd, inc, 1) != 1)
/* IPV4 */
if (ls_recv_str(rpipefd, &n->ipv4) < 0)
return -1;
nbytes_id++;
} while (*inc++ != '\0');
if (nbytes_id > 1) {
/* save it where the caller wants it */
*save_buf = strdup(*read_buf);
if (!*save_buf)
/* IPV6 */
if (ls_recv_str(rpipefd, &n->ipv6) < 0)
return -1;
}
......
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