[lxc-devel] [PATCH v2 2/3] lxccontainer.c: split up create_run_template() again
Serge Hallyn
serge.hallyn at ubuntu.com
Mon Oct 20 21:43:16 UTC 2014
(Just a note to clarify - I'm waiting on pushing 1/3 and 2/3 until 3/3 is
agreed-upon)
Quoting Serge Hallyn (serge.hallyn at ubuntu.com):
> Quoting TAMUKI Shoichi (tamuki at linet.gr.jp):
> > Split prepend_lxc_usernsexec() off from create_run_template() to allow
> > common use of the function.
> >
> > Signed-off-by: TAMUKI Shoichi <tamuki at linet.gr.jp>
>
> Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>
>
> > ---
> > v2:
> > - adjust to fit with the other patches.
> > - correct misspelling in commit message.
> >
> > src/lxc/lxccontainer.c | 230 ++++++++++++++++++++++++++-----------------------
> > 1 file changed, 121 insertions(+), 109 deletions(-)
> >
> > diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> > index 07ffc08..4df1a4b 100644
> > --- a/src/lxc/lxccontainer.c
> > +++ b/src/lxc/lxccontainer.c
> > @@ -878,6 +878,8 @@ static char *lxcbasename(char *path)
> >
> > /* Require that callers free the returned string. */
> > static char *figureout_rootfs(struct lxc_conf *conf);
> > +static char **prepend_lxc_usernsexec(char **tpath, struct lxc_conf *conf,
> > + int nargs, char **newargv);
> >
> > static bool create_run_template(struct lxc_container *c, char *tpath, bool quiet,
> > char *const argv[])
> > @@ -964,115 +966,11 @@ static bool create_run_template(struct lxc_container *c, char *tpath, bool quiet
> > exit(1);
> > newargv[nargs - 1] = NULL;
> >
> > - /*
> > - * If we're running the template in a mapped userns, then
> > - * we prepend the template command with:
> > - * lxc-usernsexec <-m map1> ... <-m mapn> --
> > - * and we append "--mapped-uid x", where x is the mapped uid
> > - * for our geteuid()
> > - */
> > - if (!lxc_list_empty(&conf->id_map)) {
> > - int n2args = 1;
> > - char txtuid[20];
> > - char txtgid[20];
> > - char **n2 = malloc(n2args * sizeof(*n2));
> > - struct lxc_list *it;
> > - struct id_map *map;
> > -
> > - if (!n2) {
> > - SYSERROR("out of memory");
> > - exit(1);
> > - }
> > - newargv[0] = tpath;
> > - tpath = "lxc-usernsexec";
> > - n2[0] = "lxc-usernsexec";
> > - lxc_list_for_each(it, &conf->id_map) {
> > - map = it->elem;
> > - n2args += 2;
> > - n2 = realloc(n2, n2args * sizeof(char *));
> > - if (!n2)
> > - exit(1);
> > - n2[n2args-2] = "-m";
> > - n2[n2args-1] = malloc(200);
> > - if (!n2[n2args-1])
> > - exit(1);
> > - ret = snprintf(n2[n2args-1], 200, "%c:%lu:%lu:%lu",
> > - map->idtype == ID_TYPE_UID ? 'u' : 'g',
> > - map->nsid, map->hostid, map->range);
> > - if (ret < 0 || ret >= 200)
> > - exit(1);
> > - }
> > - int hostid_mapped = mapped_hostid(geteuid(), conf, ID_TYPE_UID);
> > - int extraargs = hostid_mapped >= 0 ? 1 : 3;
> > - n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
> > - if (!n2)
> > - exit(1);
> > - if (hostid_mapped < 0) {
> > - hostid_mapped = find_unmapped_nsuid(conf, ID_TYPE_UID);
> > - n2[n2args++] = "-m";
> > - if (hostid_mapped < 0) {
> > - ERROR("Could not find free uid to map");
> > - exit(1);
> > - }
> > - n2[n2args++] = malloc(200);
> > - if (!n2[n2args-1]) {
> > - SYSERROR("out of memory");
> > - exit(1);
> > - }
> > - ret = snprintf(n2[n2args-1], 200, "u:%d:%d:1",
> > - hostid_mapped, geteuid());
> > - if (ret < 0 || ret >= 200) {
> > - ERROR("string too long");
> > - exit(1);
> > - }
> > - }
> > - int hostgid_mapped = mapped_hostid(getegid(), conf, ID_TYPE_GID);
> > - extraargs = hostgid_mapped >= 0 ? 1 : 3;
> > - n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
> > - if (!n2)
> > - exit(1);
> > - if (hostgid_mapped < 0) {
> > - hostgid_mapped = find_unmapped_nsuid(conf, ID_TYPE_GID);
> > - n2[n2args++] = "-m";
> > - if (hostgid_mapped < 0) {
> > - ERROR("Could not find free uid to map");
> > - exit(1);
> > - }
> > - n2[n2args++] = malloc(200);
> > - if (!n2[n2args-1]) {
> > - SYSERROR("out of memory");
> > - exit(1);
> > - }
> > - ret = snprintf(n2[n2args-1], 200, "g:%d:%d:1",
> > - hostgid_mapped, getegid());
> > - if (ret < 0 || ret >= 200) {
> > - ERROR("string too long");
> > - exit(1);
> > - }
> > - }
> > - n2[n2args++] = "--";
> > - for (i = 0; i < nargs; i++)
> > - n2[i + n2args] = newargv[i];
> > - n2args += nargs;
> > - // Finally add "--mapped-uid $uid" to tell template what to chown
> > - // cached images to
> > - n2args += 4;
> > - n2 = realloc(n2, n2args * sizeof(char *));
> > - if (!n2) {
> > - SYSERROR("out of memory");
> > - exit(1);
> > - }
> > - // note n2[n2args-1] is NULL
> > - n2[n2args-5] = "--mapped-uid";
> > - snprintf(txtuid, 20, "%d", hostid_mapped);
> > - n2[n2args-4] = txtuid;
> > - n2[n2args-3] = "--mapped-gid";
> > - snprintf(txtgid, 20, "%d", hostgid_mapped);
> > - n2[n2args-2] = txtgid;
> > - n2[n2args-1] = NULL;
> > - free(newargv);
> > - newargv = n2;
> > - }
> > + /* prepend the template command with lxc-usernsexec */
> > + if (!lxc_list_empty(&conf->id_map))
> > + newargv = prepend_lxc_usernsexec(&tpath, conf,
> > + nargs, newargv);
> > +
> > /* execute */
> > execvp(tpath, newargv);
> > SYSERROR("failed to execute template %s", tpath);
> > @@ -1141,6 +1039,120 @@ out:
> > return rootfs;
> > }
> >
> > +/*
> > + * If we're running the template in a mapped userns, then
> > + * we prepend the template command with:
> > + * lxc-usernsexec <-m map1> ... <-m mapn> --
> > + * and we append "--mapped-uid x", where x is the mapped uid
> > + * for our geteuid()
> > + */
> > +static char **prepend_lxc_usernsexec(char **tpath, struct lxc_conf *conf,
> > + int nargs, char **newargv)
> > +{
> > + int n2args = 1;
> > + char txtuid[20];
> > + char txtgid[20];
> > + int i, ret;
> > + char **n2 = malloc(n2args * sizeof(*n2));
> > + struct lxc_list *it;
> > + struct id_map *map;
> > +
> > + if (!n2) {
> > + SYSERROR("out of memory");
> > + exit(1);
> > + }
> > + newargv[0] = *tpath;
> > + *tpath = "lxc-usernsexec";
> > + n2[0] = "lxc-usernsexec";
> > + lxc_list_for_each(it, &conf->id_map) {
> > + map = it->elem;
> > + n2args += 2;
> > + n2 = realloc(n2, n2args * sizeof(char *));
> > + if (!n2)
> > + exit(1);
> > + n2[n2args-2] = "-m";
> > + n2[n2args-1] = malloc(200);
> > + if (!n2[n2args-1])
> > + exit(1);
> > + ret = snprintf(n2[n2args-1], 200, "%c:%lu:%lu:%lu",
> > + map->idtype == ID_TYPE_UID ? 'u' : 'g',
> > + map->nsid, map->hostid, map->range);
> > + if (ret < 0 || ret >= 200)
> > + exit(1);
> > + }
> > + int hostid_mapped = mapped_hostid(geteuid(), conf, ID_TYPE_UID);
> > + int extraargs = hostid_mapped >= 0 ? 1 : 3;
> > + n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
> > + if (!n2)
> > + exit(1);
> > + if (hostid_mapped < 0) {
> > + hostid_mapped = find_unmapped_nsuid(conf, ID_TYPE_UID);
> > + n2[n2args++] = "-m";
> > + if (hostid_mapped < 0) {
> > + ERROR("Could not find free uid to map");
> > + exit(1);
> > + }
> > + n2[n2args++] = malloc(200);
> > + if (!n2[n2args-1]) {
> > + SYSERROR("out of memory");
> > + exit(1);
> > + }
> > + ret = snprintf(n2[n2args-1], 200, "u:%d:%d:1",
> > + hostid_mapped, geteuid());
> > + if (ret < 0 || ret >= 200) {
> > + ERROR("string too long");
> > + exit(1);
> > + }
> > + }
> > + int hostgid_mapped = mapped_hostid(getegid(), conf, ID_TYPE_GID);
> > + extraargs = hostgid_mapped >= 0 ? 1 : 3;
> > + n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
> > + if (!n2)
> > + exit(1);
> > + if (hostgid_mapped < 0) {
> > + hostgid_mapped = find_unmapped_nsuid(conf, ID_TYPE_GID);
> > + n2[n2args++] = "-m";
> > + if (hostgid_mapped < 0) {
> > + ERROR("Could not find free uid to map");
> > + exit(1);
> > + }
> > + n2[n2args++] = malloc(200);
> > + if (!n2[n2args-1]) {
> > + SYSERROR("out of memory");
> > + exit(1);
> > + }
> > + ret = snprintf(n2[n2args-1], 200, "g:%d:%d:1",
> > + hostgid_mapped, getegid());
> > + if (ret < 0 || ret >= 200) {
> > + ERROR("string too long");
> > + exit(1);
> > + }
> > + }
> > + n2[n2args++] = "--";
> > + for (i = 0; i < nargs; i++)
> > + n2[i + n2args] = newargv[i];
> > + n2args += nargs;
> > + // Finally add "--mapped-uid $uid" to tell template what to chown
> > + // cached images to
> > + n2args += 4;
> > + n2 = realloc(n2, n2args * sizeof(char *));
> > + if (!n2) {
> > + SYSERROR("out of memory");
> > + exit(1);
> > + }
> > + // note n2[n2args-1] is NULL
> > + n2[n2args-5] = "--mapped-uid";
> > + snprintf(txtuid, 20, "%d", hostid_mapped);
> > + n2[n2args-4] = txtuid;
> > + n2[n2args-3] = "--mapped-gid";
> > + snprintf(txtgid, 20, "%d", hostgid_mapped);
> > + n2[n2args-2] = txtgid;
> > + n2[n2args-1] = NULL;
> > + free(newargv);
> > + newargv = n2;
> > + return newargv;
> > +}
> > +
> > static bool prepend_lxc_header(char *path, const char *t, char *const argv[])
> > {
> > long flen;
> > --
> > 1.9.0
> > _______________________________________________
> > lxc-devel mailing list
> > lxc-devel at lists.linuxcontainers.org
> > http://lists.linuxcontainers.org/listinfo/lxc-devel
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