From fc1be3d5ab4863c173796fe23f4ed00984d6ce8a Mon Sep 17 00:00:00 2001 From: David Gibson Date: Mon, 12 Sep 2022 22:24:05 +1000 Subject: Clean up and rename conf_ns_open() conf_ns_open() opens file descriptors for the namespaces pasta needs, but it doesnt really have anything to do with configuration any more. For better clarity, move it to pasta.c and rename it pasta_open_ns(). This makes the symmetry between it and pasta_start_ns() more clear, since these represent the two basic ways that pasta can operate, either attaching to an existing namespace/process or spawning a new one. Since its no longer validating options, the errors it could return shouldn't cause a usage message. Just exit directly with an error instead. Signed-off-by: David Gibson --- conf.c | 72 +---------------------------------------------------------------- pasta.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ pasta.h | 1 + 3 files changed, 68 insertions(+), 71 deletions(-) diff --git a/conf.c b/conf.c index d1afea9..8477a6e 100644 --- a/conf.c +++ b/conf.c @@ -20,7 +20,6 @@ #include #include #include -#include #include #include #include @@ -574,73 +573,6 @@ static int conf_pasta_ns(int *netns_only, char *userns, char *netns, return 0; } -/** - * conf_ns_check() - Check if we can enter configured namespaces - * @arg: Execution context - * - * Return: 0 - */ -static int conf_ns_check(void *arg) -{ - struct ctx *c = (struct ctx *)arg; - - if ((!c->netns_only && setns(c->pasta_userns_fd, CLONE_NEWUSER)) || - setns(c->pasta_netns_fd, CLONE_NEWNET)) - c->pasta_userns_fd = c->pasta_netns_fd = -1; - - return 0; - -} - -/** - * conf_ns_open() - Open network, user namespaces descriptors from configuration - * @c: Execution context - * @userns: --userns argument, can be an empty string - * @netns: network namespace path - * - * Return: 0 on success, negative error code otherwise - */ -static int conf_ns_open(struct ctx *c, const char *userns, const char *netns) -{ - int ufd = -1, nfd = -1; - - nfd = open(netns, O_RDONLY | O_CLOEXEC); - if (nfd < 0) { - err("Couldn't open network namespace %s", netns); - return -ENOENT; - } - - if (!c->netns_only && *userns) { - ufd = open(userns, O_RDONLY | O_CLOEXEC); - if (ufd < 0) { - close(nfd); - err("Couldn't open user namespace %s", userns); - return -ENOENT; - } - } - - c->pasta_netns_fd = nfd; - c->pasta_userns_fd = ufd; - - NS_CALL(conf_ns_check, c); - - if (c->pasta_netns_fd < 0) { - err("Couldn't switch to pasta namespaces"); - return -ENOENT; - } - - if (!c->no_netns_quit) { - char buf[PATH_MAX]; - - strncpy(buf, netns, PATH_MAX); - strncpy(c->netns_base, basename(buf), PATH_MAX - 1); - strncpy(buf, netns, PATH_MAX); - strncpy(c->netns_dir, dirname(buf), PATH_MAX - 1); - } - - return 0; -} - /** * conf_ip4() - Verify or detect IPv4 support, get relevant addresses * @ifi: Host interface to attempt (0 to determine one) @@ -1598,9 +1530,7 @@ void conf(struct ctx *c, int argc, char **argv) if (c->mode == MODE_PASTA) { if (*netns) { - ret = conf_ns_open(c, userns, netns); - if (ret < 0) - usage(argv[0]); + pasta_open_ns(c, userns, netns); } else { pasta_start_ns(c, argc - optind, argv + optind); } diff --git a/pasta.c b/pasta.c index 0bdb655..0fd45e4 100644 --- a/pasta.c +++ b/pasta.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -101,6 +102,71 @@ netns: return 0; } +/** + * ns_check() - Check if we can enter configured namespaces + * @arg: Execution context + * + * Return: 0 + */ +static int ns_check(void *arg) +{ + struct ctx *c = (struct ctx *)arg; + + if ((!c->netns_only && setns(c->pasta_userns_fd, CLONE_NEWUSER)) || + setns(c->pasta_netns_fd, CLONE_NEWNET)) + c->pasta_userns_fd = c->pasta_netns_fd = -1; + + return 0; + +} + +/** + * pasta_open_ns() - Open network, user namespaces descriptors + * @c: Execution context + * @userns: --userns argument, can be an empty string + * @netns: network namespace path + * + * Return: 0 on success, negative error code otherwise + */ +void pasta_open_ns(struct ctx *c, const char *userns, const char *netns) +{ + int ufd = -1, nfd = -1; + + nfd = open(netns, O_RDONLY | O_CLOEXEC); + if (nfd < 0) { + err("Couldn't open network namespace %s", netns); + exit(EXIT_FAILURE); + } + + if (!c->netns_only && *userns) { + ufd = open(userns, O_RDONLY | O_CLOEXEC); + if (ufd < 0) { + close(nfd); + err("Couldn't open user namespace %s", userns); + exit(EXIT_FAILURE); + } + } + + c->pasta_netns_fd = nfd; + c->pasta_userns_fd = ufd; + + NS_CALL(ns_check, c); + + if (c->pasta_netns_fd < 0) { + err("Couldn't switch to pasta namespaces"); + exit(EXIT_FAILURE); + } + + if (!c->no_netns_quit) { + char buf[PATH_MAX] = { 0 }; + + strncpy(buf, netns, PATH_MAX - 1); + strncpy(c->netns_base, basename(buf), PATH_MAX - 1); + strncpy(buf, netns, PATH_MAX - 1); + strncpy(c->netns_dir, dirname(buf), PATH_MAX - 1); + } +} + /** * struct pasta_setup_ns_arg - Argument for pasta_setup_ns() * @c: Execution context diff --git a/pasta.h b/pasta.h index 19b2e54..a1937b2 100644 --- a/pasta.h +++ b/pasta.h @@ -6,6 +6,7 @@ #ifndef PASTA_H #define PASTA_H +void pasta_open_ns(struct ctx *c, const char *userns, const char *netns); void pasta_start_ns(struct ctx *c, int argc, char *argv[]); void pasta_ns_conf(struct ctx *c); void pasta_child_handler(int signal); -- cgit v1.2.3